Name: ssvep-based experimental procedure for brain-robot interaction with humanoid robots
Uploaded: 2015-11-24T15:00:00.000+00:00
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Description: Watch this Scientific Journal Video about SSVEP-based Experimental Procedure for Brain-Robot Interaction with Humanoid Robots at JoVE.com

<p class="jove_content"> Les auteurs tiennent à exprimer leur gratitude à M. Hong Hu pour son aide dans l&#39;exécution des expériences rapportées dans le présent document. Ce travail a été financé en partie par la Fondation nationale des sciences naturelles de Chine (n ° 61473207). </p>

<p class="jove_title"> 1. Acquisition de signaux EEG </p><ol><li> Expliquer la procédure expérimentale pour le sujet et obtenir le consentement éclairé écrit de participer à des expériences. </li><li> Mesurer la circonférence de la tête du sujet en utilisant un ruban à mesurer et sélectionnez la taille de bonnet EEG qui est proche de la mesure. L&#39;arrangement d&#39;électrodes est basé sur le «système 10-20 international&quot; <sup>12.</sup> </li><li> Mesurez la distance entre le nasion et inion. Utilisez un crayon de marquage de la peau à l&#39;occasion de 10% de la distance de référence pour aligner le capuchon, et marquer le point médian de la distance que le sommet sur le cuir chevelu du sujet. </li><li> Placez le bouchon EEG sur le sujet en alignant la barre des 10% avec le milieu des électrodes PF1 et PF2. Électrode de position Cz de la capsule sur le sommet. </li><li> Assurez-vous que le Fz, Cz, Pz et Oz sont sur la ligne médiane de la tête, et que chaque paire d&#39;électrodes situées de chaque côté de la ligne médiane sont sur une ligne horizontale. </li><li>Enduire les électrodes REF1 et REF2 avec gel conducteur. Placer les électrodes de référence sur les mastoïdes gauche et droite à l&#39;aide de ruban adhésif médical. Serrez la jugulaire. </li><li> Placez une seringue pointe arrondie dans les porte-électrodes et injecter un gel conducteur dans chaque électrode dans l&#39;ordre suivant: d&#39;abord, le «terrain» électrode sur le front et le deuxième, les cinq électrodes utilisées dans l&#39;expérience, O2, O1, Oz, Pz et Cz. </li><li> Seat l&#39;objet dans un confortable fauteuil 60 cm en face d&#39;un moniteur de relance. Demandez au sujet de garder ses / ses yeux dans le même plan horizontal avec le centre de l&#39;écran. </li><li> Connecter les fils d&#39;électrodes au système d&#39;acquisition de données EEG. Configurez le taux d&#39;échantillonnage de 1 kHz. </li><li> Examiner la qualité du signal EEG sur le DPC dédié. Si il ya un problème avec une électrode particulière, gel réinjecter pour régler l&#39;impédance du canal. </li><li> Utilisez le CPS dédié à clignoter quatre images de robots à des fréquences de 4.615, 12, 15 et 20Hz comme stimuli visuels sur l&#39;interface utilisateur comme le montre <strong>la</strong> figure 2. </li></ol><p class="jove_title"> 2. Hors Analyser SSVEP Caractéristiques </p><ol><li> Mener des 32 essais d&#39;expériences de formation hors ligne pour chaque sujet et enregistrer leurs signaux cérébraux acquis du système EEG long de ce processus. <br /> Remarque: Ce processus est mené uniquement par des sujets pour la première fois de l&#39;expérience pour établir leurs vecteurs caractéristiques de SSVEP et de former le classificateur. </li><li> Quand un procès commence, sélectionnez un stimulus comme cible au hasard et afficher une flèche jaune au-dessus. </li><li> 1 secondes plus tard, scintiller les quatre stimuli visuels à des fréquences différentes sur l&#39;interface utilisateur pendant 5 sec. </li><li> Demander le sujet pour se concentrer sur l&#39;objectif de relance sélectionnée tout en gardant son / sa mouvement du corps à un minimum. </li><li> Après chaque essai, donner le sujet 3 sec pour se détendre, et ensuite commencer à l&#39;essai suivant. </li><li> Lorsque tous les essais sont terminés, lire les données enregistrées. Extrait d&#39;une époque données 3-sec être<html> entre 2 et 5 secondes après le déclenchement qui sélectionne un stimulus comme la cible dans chaque procès. </li><li> Calculer la densité spectrale de puissance (PSD) des époques de données en utilisant l&#39;analyseur de données hors ligne dans les scripts MATLAB. Utiliser l&#39;algorithme de traitement décrit en détail ci-dessous: <ol><li> Calculer les coefficients analyse de corrélation canonique (CCA) des données multicanal de l&#39;EEG avec des données de référence. CCA est une méthode statistique multivariée utilisée pour deux ensembles de données pour trouver leur corrélation sous-jacent <sup>13.</sup> Considérant le segment 3s de données multicanal EEG <em>X</em> et les données de référence <em>Y</em> de la même longueur, utiliser CCA pour trouver les vecteurs de poids, <em>W <sub>x</sub></em> et <em><sub>W</sub> y,</em> afin de maximiser le coefficient de corrélation <em>ρ entre</em> x <em>= X <sup>T</sup> W <sub>x</sub> et</em> y = <em>Y <sup>T</sup> W <sub>y.</sub></em> Définissez les données de référence pour être les signaux périodiques à certaines fréquences de stimulation. <br />/ftp_upload/53558/53558eq1.jpg &quot;/&gt; <br /> où <em><sub>f</sub> 1, f <sub>2,</sub> f <sub>3,</sub> f <sub>4 sont</sub></em> les fréquences de caractéristiques des quatre stimuli visuels. </li><li> Filtrer spatialement les données multicanal EEG <em>X</em> en utilisant les coefficients DPA calculée <em>W <sub>x</sub></em> pour obtenir une seule dimension filtrés données <em>x,</em> qui a la corrélation la plus évidente avec la combinaison linéaire des données de référence. </li><li> Calculer le PSD des données <em>x</em> filtré spatialement en utilisant la transformée de Fourier rapide (FFT). <br /><img alt="Equation 2" src="/files/ftp_upload/53558/53558eq2.jpg" /><br /> <em>où</em> N est la taille <em><sub>de FFT</sub></em> de l&#39;échantillon de données <em>x,</em> et FFT <em>(x, N <sub>FFT)</sub> renvoie</em> transformée de Fourier discrète <em><sub>FFT</sub></em> -point de <em>N x.</em> </li><li> Normaliser le PSD par rapport à sa valeur moyenne entre 3 et 30 Hz. <br /><img alt="Équation 3" src="/files/ftp_upload/53558/53558eq3.jpg" /><br /> où60; <img alt="Équation 3 Dénominateur" src="/files/ftp_upload/53558/53558eq3denominator.jpg" /> désigne la moyenne du spectre de puissance comprise entre 3 et 30 Hz. </li></ol></li><li> Calibrer les paramètres de classification pour les quatre fréquences de stimulation. Tout d&#39;abord, observer le spectre PSD normalisée qui correspond à son objectif de relance, et de configurer manuellement la fréquence avec la plus forte amplitude PSD que la fréquence de fonction. Basé sur la fréquence caractéristique, diviser les données PSD normalisées en deux ensembles: l&#39;un est acquise lorsque le stimulus correspondant est sélectionné comme cible, et l&#39;autre est acquise lorsque les stimuli non-cibles sont sélectionnés. Calculer la valeur moyenne de chaque série, respectivement. Déterminer le seuil de la médiane des deux valeurs moyennes de classer la cible et non-cible fixe <sup>14.</sup> </li></ol><p class="jove_title"> 3. Traitement des signaux du cerveau en ligne </p><ol><li> Ouvrir le processeur de signal en ligne comme <strong>le</strong> montre la figure <strong>3,</strong> qui est développé belon sur l&#39;environnement OpenViBE et les scripts MATLAB, sur le DPC pour traiter les signaux du cerveau en ligne. </li><li> Double-cliquez sur la boîte de Signal acquisition et de traitement, qui est marqué avec un cycle <strong>rouge</strong> dans la figure <strong>3,</strong> pour ouvrir la fenêtre de réglage OpenViBE. Configurer les paramètres de classification pour le sujet:. Définir le taux d&#39;échantillonnage de 1 kHz, régler la longueur de temps pour FFT que 3 sec, et régler les fréquences de longs selon les résultats de l&#39;analyse en ligne, <em>par exemple,</em> 4.667, 24, 15 et 20 Hz . </li><li> Cliquez sur le bouton commence à courir le processeur de signaux en ligne, qui traite les données en temps réel en utilisant l&#39;algorithme suivant en trois étapes. </li><li> Tout d&#39;abord, l&#39;algorithme acquiert des données provenant des canaux EEG Oz, O1, O2, Pz et CPZ du système EEG toutes les 0.5s, et extrait le segment de données de la dernière ligne de traitement 3s. </li><li> Deuxièmement, l&#39;algorithme traite le segment de données 3-sec en utilisant les algorithmes décrits à l&#39;étape 2.7, et calcule en temps réel le PSD pour Classification. </li><li> Troisièmement, l&#39;algorithme classe les schémas des ondes cérébrales en fonction des amplitudes PSD dans les quatre fréquences de fonction. Lorsque l&#39;amplitude de fréquence d&#39;une caractéristique est supérieur à un seuil donné, classifier le stimulus scintillement correspondant à la fréquence en tant que cible de SSVEP. </li></ol><p class="jove_title"> 4. Connecter le Robot Humanoïde </p><ol><li> Appuyez sur le bouton de la poitrine du robot humanoïde et attendez qu&#39;il démarre. <br /> Remarque: Ce processus prend environ 1 min et est terminée lorsque le robot dit &quot;OGNAK GNOUK&quot;, tandis que le bouton de la poitrine devient blanc. </li><li> Établir sa WiFi (Wireless Fidelity) connexion à la DPC <sup>15.</sup> </li><li> Ouvrez le contrôleur robot programmé en C ++ scripts Visual sur le DPC. Le contrôleur reçoit les résultats de la classification de la Signal Processor ligne par l&#39;intermédiaire de réalité virtuelle périphérique réseau (VRPN) interface, les traduit en commandes de robots, et contrôle les comportements correspondants du humanoid robot via une connexion sans fil. </li><li> Configurez le contrôleur de robot en entrant l&#39;adresse IP du robot en fonction de sa connexion WiFi, définissant trois séries de comportements du robot qui peut facilement être modifiée pour effectuer les trois tâches différentes, et en définissant les paramètres d&#39;exécution de ces <em>comportements</em> (par exemple., La vitesse de marche ou distance) pour adapter l&#39;exigence de tâche. <br /> NOTE: Plus de détails de ces comportements sont décrits dans les étapes 5.2.1, 5.3.1, 5.4.1 et. </li><li> Cliquez sur le bouton Générer de la plateforme Visual Studio pour exécuter le Contrôleur de Robot. </li><li> Ouvrez le programme Chorégraphe sur la CPS. Cliquez sur «Se connecter à&quot; bouton pour faire apparaître un widget de connexion. Sélectionnez le robot doit être contrôlée en fonction de son adresse IP, et double-cliquez sur son icône pour s&#39;y connecter. </li><li> Ouvrez l&#39;écran vidéo dans le menu d&#39;affichage dans la barre de menu Chorégraphe, et déplacer le moniteur à l&#39;avant de l&#39;interface utilisateur pour afficher des commentaires de la vidéo en direct depuis la caméra du robot. </li></ol> &lt;p class = &quot;jove_title&quot;&gt; 5. Mener des expériences de contrôle en boucle fermée </p><ol><li> Demander le sujet pour effectuer trois tâches de contrôle en boucle fermée spécifiques au sein des environnements différents afin d&#39;évaluer la performance de l&#39;interaction cerveau-robots. <br /> REMARQUE: ces tâches, qui sont importants dans les applications robotiques, car ils sont utiles pour aider les personnes handicapées et les personnes âgées dans leur vie quotidienne, besoin d&#39;activer différents comportements du robot. </li><li> Effectuer la première tâche de contrôle en boucle fermée à la téléprésence contrôler le robot humanoïde via des signaux du cerveau à marcher à travers les obstacles et pousser un interrupteur pour allumer la lumière, comme <strong>le</strong> montre la figure <strong>4.</strong> <ol><li> Pour accomplir la première tâche, contrôler les comportements des robots qui sont codées par les quatre stimuli SSVEP comme: un pas en avant avec une distance fixe de 0,15 m, tourner à gauche avec un radian fixe de 0,3 rad, en tournant à droite avec un radian fixe de 0,3 rad, et en poussant le commutateur à l&#39;aide de sa main droite. <br /> REMARQUE: la configuraprocessus d&#39;est décrite dans l&#39;étape 4.4. </li><li> Informer le sujet de l&#39;objectif de la tâche et les quatre comportements à être contrôlé. </li><li> Exécutez le Robot Controller comme dans les étapes 4.5-4.7, et commencer l&#39;expérience. Donnez le sujet de la liberté de percevoir l&#39;environnement et de prendre des décisions basées sur les commentaires de la vidéo en direct, et pour activer les comportements du robot en regardant fixement les stimuli correspondants. <br /> REMARQUE: aucune instruction ou de l&#39;aide devrait être accordée à l&#39;objet, sauf dans les situations d&#39;urgence, <em>par exemple,</em> le robot est sur ​​le point d&#39;entrer en collision avec un obstacle.. </li></ol></li><li> Effectuer la deuxième tâche à la téléprésence contrôler le robot humanoïde via des signaux du cerveau à marcher vers l&#39;escalier suivant le panneau de sortie, comme le montre la <strong>Figure 5.</strong> Lorsque confrontant passants, demandez au sujet de contrôler le robot à-dire &quot;excusez-moi&quot; et attendre que le passants à céder. <ol><li> Contrôler les comportements du robot codées par les quatre stimuli SSVEP que: marche en avant continuously à une vitesse de 0,05 m / s, en tournant à gauche en continu à une vitesse de 0,1 rad / s, en tournant à droite en continu à une vitesse de 0,1 rad / s, et l&#39;arrêt de tous les comportements de marche. </li><li> Mettez le Robot Controller à la fonction de commande posture dépendante <sup>16.</sup> <br /> REMARQUE: lorsque le robot marche, cette fonction utilise la quatrième relance que la commande d&#39;arrêter les comportements de marche; lorsque le robot ne marche pas, il utilise la quatrième relance de contrôler le robot à-dire &quot;excusez-moi&quot;. La fonction est implémentée dans les scripts C de par la détection de l&#39;état de marche du robot. </li><li> Informer le sujet de l&#39;objectif de la tâche et les cinq comportements à être contrôlé. </li><li> Exécutez le contrôleur de robot et commencer l&#39;expérience, comme décrit à l&#39;étape 5.2.3. </li></ol></li><li> Mener la troisième tâche de téléprésence contrôler le robot humanoïde à marcher vers une cible de ballon, de le ramasser et de le livrer à la main de l&#39;objet, comme le montre la <strong>Figure 6</strong>. <ol><li> Contrôler les comportements du robot codées par les quatre stimuli SSVEP que: un pas en avant avec une distance fixe de 0,15 m, tourner à gauche avec un radian fixe de 0,3 rad, en tournant à droite avec un radian fixe de 0,3 rad, et ramasser des objets. </li><li> Activez la fonction de contrôle posture dépendant dans le Contrôleur de Robot de réutiliser la quatrième relance que la commande de débarquer l&#39;objet quand il a déjà été ramassé. </li><li> Informer le sujet de l&#39;objectif de la tâche et les cinq comportements à être contrôlé. </li><li> Exécutez le contrôleur de robot et commencer l&#39;expérience, comme décrit à l&#39;étape 5.2.3. </li></ol></li></ol>

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H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+dual-frequency+stimulation+method+to+increase+the+number+of+visual+stimuli+for+multi-class+SSVEP-based+brain-computer+interface+(BCI).">A new dual-frequency stimulation method to increase the number of visual stimuli for multi-class SSVEP-based brain-computer interface (BCI).</a> <em style='font-style: italic'>Brain Res</em>. <b>1515</b>, 66-77 (2013).</li><li>Wang, M., Daly, I., Allison, B., Jin, J., Zhang, Y., Chen, L., Wang, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+hybrid+BCI+paradigm+based+on+P300+and+SSVEP.">A new hybrid BCI paradigm based on P300 and SSVEP.</a> <em style='font-style: italic'>J Neurosci Methods</em>. <b>244</b>, 16-25 (2015).</li><li>Allison, B. Z., Jin, J., Zhang, Y., Wang, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+four-choice+hybrid+P300+SSVEP+BCI+for+improved+accuracy.">A four-choice hybrid P300 SSVEP BCI for improved accuracy.</a> <em style='font-style: italic'>Brain-Computer Interfaces</em>. <b>1</b>, 17-26 (2014).</li><li>Pan, J. H., Xie, Q., Herman, Y., Wang, F., Di, H., Laureys, S., Yu, R., Li, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detecting+awareness+in+patients+with+disorders+of+consciousness+using+a+hybrid+brain-computer+interface.">Detecting awareness in patients with disorders of consciousness using a hybrid brain-computer interface.</a> <em style='font-style: italic'>J. Neural. Eng</em>. <b>11</b>, 056007 (2014).</li><li>Li, J., Ji, H., Cao, L., Zhang, D., Gu, R., Xia, B., Wu, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+and+application+of+a+hybrid+brain+computer+interface+for+real+wheelchair+parallel+control+with+multi-degree+of+freedom.">Evaluation and application of a hybrid brain computer interface for real wheelchair parallel control with multi-degree of freedom.</a> <em style='font-style: italic'>Int J Neural Syst</em>. <b>24</b>, 1450014-14 (2014).</li><li>Zhao, J., Meng, Q., Li, W., Li, M., Chen, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SSVEP-based+hierarchical+architecture+for+control+of+a+humanoid+robot+with+mind.">SSVEP-based hierarchical architecture for control of a humanoid robot with mind.</a> <em style='font-style: italic'>Proc. 11th World Congress on Intelligent Control and Automation</em>. , 2401-2406 (2014).</li><li>Zhu, D., Bieger, J., Molina, G. G., Aarts, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+survey+of+stimulation+methods+used+in+SSVEP-based+BCIs.">A survey of stimulation methods used in SSVEP-based BCIs.</a> <em style='font-style: italic'>Comput Intell Neurosci</em>. <b>2010</b>, 1-12 (2010).</li><li>Muller-Putz, G. R., Scherer, R., Brauneis, C., Pfurtscheller, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Steady-state+visual+evoked+potential+(SSVEP)-based+communication:+impact+of+harmonic+frequency+components.">Steady-state visual evoked potential (SSVEP)-based communication: impact of harmonic frequency components.</a> <em style='font-style: italic'>J Neural Eng</em>. <b>2</b>, 123-130 (2005).</li></ol>

<p class='jove_content'>The authors have nothing to disclose.</p>

<p class="jove_content"> Cet article présente une procédure expérimentale basée SSVEP à établir le système d&#39;interaction cerveau-robot avec des robots humanoïdes en intégrant plusieurs programmes logiciels. Étant donné que l&#39;intention humaine est perçue par l&#39;interprétation des signaux d&#39;EEG en temps réel, il est essentiel de vérifier les connexions d&#39;électrodes EEG et des qualités de signal avant d&#39;effectuer l&#39;expérience. Si les signaux acquis de toutes les électrodes sont de mauvaises qualités, ...

<p class="jove_content"> Brain-Robot Interaction (BRI), qui fournit une voie de communication innovant entre l&#39;humain et un dispositif robotique via des signaux du cerveau, est prospective pour aider les personnes handicapées dans leur vie quotidienne <sup>1,2.</sup> Une variété de méthodes sont en mesure d&#39;acquérir les signaux du cerveau soit invasive ou non invasive, comme électrocorticographie (ECoG), électroencéphalogramme (EEG), l&#39;imagerie par résonance magnétique fonctionnelle (IRMf), etc. La méthode non-invasive la plus couramment utilisée pour la construction du système BRI est d&#39;acquérir des signaux EEG à partir des électrodes placées sur le cuir chevelu. Cette méthode est peu coûteuse, facile à utiliser, et offre une résolution temporelle acceptable <sup>3.</sup> Parmi une variété de dispositifs robotiques, robots humanoïdes sont avancés car ils sont créés pour imiter certains des mêmes tâches physiques et mentales que les humains subissent quotidiennement. BRI avec un robot humanoïde va jouer un rôle important en aidant les malades et les personnes âgées, ainsi que l&#39;exécution des emplois insalubres ou dangereux. Mais le contrôled&#39;un robot humanoïde à travers le système BRI est très difficile, car le robot humanoïde avec le mouvement du corps entier est conçu pour effectuer des tâches complexes telles que l&#39;assistance personnelle <sup>4, 5.</sup> </p><p class="jove_content"> Steady-State potentiels évoqués visuels (SSVEP) est un type de signal du cerveau provoquée par la modulation du stimulus visuel à une fréquence donnée <sup>6.</sup> Il contient des sinusoïdes à des fréquences fondamentales et harmoniques de la stimulation de scintillement, et bien en vue apparaît à travers le cortex visuel dans la région occipitale du cuir chevelu <sup>7.</sup> La raison du choix des signaux de SSVEP est que le système à base BRI-SSVEP donne un taux de transfert de l&#39;information relativement élevé et nécessite moins de formation <sup>8.</sup> Autres types d&#39;ondes cérébrales, comme les potentiels évoqués (ERP) <sup>9</sup> ou moteur-imagerie (MI) les potentiels <sup>10,</sup> peuvent également être intégrés dans cette procédure expérimentale. </p><p class="jove_content"> Notre procédure d&#39;interaction cerveau-robot humanoïderobots sont basées sur Cerebot - une plateforme de robot humanoïde de contrôle mental - constitué d&#39;un système d&#39;acquisition de données EEG et un robot humanoïde <sup>11.</sup> Le système EEG est capable d&#39;enregistrer des signaux bio-potentiel affichage acquises par divers types d&#39;électrodes de pré-processus et. Il fournit analogique multiples E / S et E / S numériques et est capable d&#39;enregistrer jusqu&#39;à 128 canaux de signaux simultanément à un taux d&#39;échantillonnage de 30 kHz avec une résolution de 16 bits. Ses kits de développement logiciel en C ++ et MATLAB sont faciles pour les utilisateurs de concevoir les procédures expérimentales. Le robot humanoïde possède 25 degrés de liberté et est équipé de plusieurs capteurs, y compris les 2 caméras, 4 micros, 2 télémètres sonar, 2 IR émetteurs et récepteurs, 1 planche d&#39;inertie, 9 capteurs tactiles, et 8 capteurs de pression. Il fournit Choregraphe et SDK C ++ pour créer et éditer les mouvements et les comportements des robots interactifs. </p><p class="jove_content"> L&#39;objectif global de cette méthode est d&#39;établir une procé expérimentale basée SSVEP-dure en intégrant plusieurs logiciels, comme OpenViBE, Chorégraphe, le logiciel central ainsi que de programmes développés utilisateur écrites en C ++ et MATLAB, afin de permettre l&#39;étude de l&#39;interaction cerveau-robot avec des robots humanoïdes <sup>11.</sup> <strong>La figure 1 montre</strong> la structure du système. L&#39;ordinateur de la présentation du stimulus dédié (CPS) affiche l&#39;interface utilisateur pour fournir le sujet avec des stimuli visuels, des instructions et des évaluations environnementales. L&#39;ordinateur de traitement de données dédié (DPC) exécute l&#39;enregistreur de données et l&#39;analyseur de données hors ligne dans le processus de formation en ligne, et exécute le processeur de signal en ligne et la commande du robot pour le contrôle en ligne du robot humanoïde. Comparé à d&#39;autres systèmes de contrôle basés SSVEP, notre système est plus fiable, plus souple, et surtout plus pratique pour être réutilisés et mis à jour comme il est développé en intégrant un certain nombre de logiciels normalisés, tels que OpenViBE, Chorégraphe, le logiciel central, et modules écrits en C ++et MATLAB. </p><p class="jove_content"> La procédure suivante a été examiné et approuvé par l&#39;université médicale comité d&#39;éthique de l&#39;hôpital général de Tianjin, et tous les sujets ont donné leur consentement par écrit. </p>

<table><tbody><tr><td>Cerebus EEG Data Acquisition System</td><td>Blackrock Microsystems</td><td>4176-9967</td><td></td></tr><tr><td>NAO humanoid robot</td><td>Aldebaran Robotics</td><td>H25</td><td></td></tr><tr><td>EEG cap</td><td>Neuroscan</td><td>8732</td><td></td></tr><tr><td>Ten20 Conductive gel</td><td>Weaver and company</td><td>10-20-8</td><td></td></tr></tbody></table>

ssvep-based experimental procedure for brain-robot interaction with humanoid robots

<p class='jove_content'>Brain-Robot Interaction (BRI), which provides an innovative communication pathway between human and a robotic device via brain signals, is prospective in helping the disabled in their daily lives. The overall goal of our method is to establish an SSVEP-based experimental procedure by integrating multiple software programs, such as OpenViBE, Choregraph, and Central software as well as user developed programs written in C++ and MATLAB, to enable the study of brain-robot interaction with humanoid robots.</p>
<p class='jove_content'>This is achieved by first placing EEG electrodes on a human subject to measure the brain responses through an EEG data acquisition system. A user interface is used to elicit SSVEP responses and to display video feedback in the closed-loop control experiments. The second step is to record the EEG signals of first-time subjects, to analyze their SSVEP features offline, and to train the classifier for each subject. Next, the Online Signal Processor and the Robot Controller are configured for the online control of a humanoid robot. As the final step, the subject completes three specific closed-loop control experiments within different environments to evaluate the brain-robot interaction performance.</p>
<p class='jove_content'>The advantage of this approach is its reliability and flexibility because it is developed by integrating multiple software programs. The results show that using this approach, the subject is capable of interacting with the humanoid robot via brain signals. This allows the mind-controlled humanoid robot to perform typical tasks that are popular in robotic research and are helpful in assisting the disabled.</p>

<p class="jove_content" fo:keep-together.within-page="1"> Les résultats présentés ici ont été obtenus à partir d&#39;un sujet mâle ayant corrigé à la normale la version. <strong>La figure 7 représente</strong> la procédure de traitement des données EEG, y compris l&#39;extraction d&#39;une époque de données multicanal <strong>(figure</strong> 7A), en filtrant spatialement les données à l&#39;aide des coefficients de DPA <strong>(figure</strong> 7B) , et le calcul du PSD normalisée <strong>(figure 7C).</strong> </p><p class="jov...

Watch this Scientific Journal Video about SSVEP-based Experimental Procedure for Brain-Robot Interaction with Humanoid Robots at JoVE.com

SSVEP-based Experimental Procedure for Brain-Robot Interaction with Humanoid Robots

<p class='jove_content'>The overall goal of this method is to establish an SSVEP-based experimental procedure by integrating multiple software programs to enable the study of brain-robot interaction with humanoid robots, which is prospective in assisting the sick and elderly as well as performing unsanitary or dangerous jobs.</p>

SSVEP basé procédure expérimentale pour Brain-Robot Interaction avec des robots humanoïdes

Brain-Robot Interaction (BRI), which provides an innovative communication pathway between human and a robotic device via brain signals, is prospective in ...

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13.1K vues.  Tianjin University. The overall goal of this method is to establish an SSVEP-based experimental procedure by integrating multiple software programs to enable the study of brain-robot interaction with humanoid robots, which is prospective in assisting the sick and elderly as well as performing unsanitary or dangerous jobs.

Vidéo: SSVEP-based Experimental Procedure for Brain-Robot Interaction with Humanoid Robots

Eusociality and Division of Labor

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Simulating Eusocial and Solitary Behavior
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">Note: In this simulation, you will portray either a eusocial or solitary animal. The goal of this simulation is to maximize your fitness by reproducing as many offspring as possible during the allotted five minutes. To do this, you must forage for resources and reproduce within the constraints of your assigned role.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Assuming a class size of 10, 4 individuals should form the solitary, or the carpenter bee group, and the remaining 6 students should form the eusocial, or the honeybee group. Note: The eusocial honeybee group will include one queen, one drone, and four workers. The queen and the drone will reproduce and protect the resources, while the workers will forage and steal resources. The solitary carpenter bee students must perform all of the tasks in this activity, with the exception of reproduction, by themselves.
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Store your resources for reproduction in the nest bowl provided by your instructor. These resources are represented by assorted beans that can be collected by foraging in the environment buckets or by stealing from other nests.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">The blue cups are male and the red cups are female, and they will be used to produce offspring. This is done by combining all four bean types in one red or blue cup to symbolize the resources needed to reproduce, and then stacking one completed cup inside a cup of the opposite color that also contains one of each bean type, to simulate a mating that produces two-cup offspring, one from each parent.
</div></li><li data-sub-note-item="1-5"><div class="lab-step">To reproduce, the solitary students will need to seek out another solitary student with an opposite-colored cup. Conversely, the eusocial queen and drone always reproduce with each other. HYPOTHESES: The hypotheses for this lab activity are based on the possible benefits of eusocial groups over solitary individuals. The alternate hypothesis could be that one group, either eusocial or solitary, will have an advantage over the other, given the ecological constraints, and this will be reflected in the number of offspring per capita. The null hypothesis might be that there will be advantage conferred by either of the strategies.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">If you are a worker in the honeybee group or a solitary student in the carpenter bee group, walk to the other side of the room to search through the rice on the foraging side of the room for one bean and bring the bean back to your bowl on the nest side of the room. Note: Even though this activity has a 5-minute time limit, running is not permitted. 
</div></li><li data-sub-note-item="1-7"><div class="lab-step">If a solitary student is not present at a neighboring bowl, you can try to steal one bean at a time, using a cup to scoop up the bean without touching the bean or the bowl with anything but the cup. You must immediately stop trying to steal if the solitary student makes it back to their bowl before you finish stealing. Note: Neighbors cannot steal from eusocial nests because the queen and drone do not leave their nest.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">You can create offspring at any time during the activity. Remember to label each cup that is contributed to an offspring with your name to keep track of your reproduction.  Note: Eusocial groups produce two offspring for their group every time they reproduce, while solitary students produce only one offspring per reproductive coupling.
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">If you were a solitary carpenter bee, record the number of offspring you produced in the appropriate row of the table. <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/36/Table_1_Eusociality_and_division_of_labor.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="2-2"><div class="lab-step">If you were a part of the eusocial honeybee group, record the number of offspring produced by your queen and drone.
</div></li><li data-sub-note-item="2-3"><div class="lab-step">To calculate the fitness for a solitary carpenter bee student, simply count the number of offspring that the student produced.
</div></li><li data-sub-note-item="2-4"><div class="lab-step">To calculate the fitness for a eusocial honeybee student, divide the number of offspring produced by the queen and drone by the number of members in the group, in this case 6, to get a per-student fitness value.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">When each student has calculated their respective fitness value, calculate the average number of offspring produced for each social category and plot these as a bar graph. <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/36/Table_2_Eusociality_and_division_of_labor.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 2</a>
</div></li><li data-sub-note-item="2-6"><div class="lab-step">Next, use Hamilton&#39;s equation to analyze the data. To do this, set r equal to the degree of relatedness, B to the class average eusocial fitness, and C to the class average solitary fitness.  r * B > C
</div></li><li data-sub-note-item="2-7"><div class="lab-step">Use these results to determine if altruistic behavior should persist in your eusocial honeybee group. Discuss the variables in Hamilton&#39;s equation that may contribute to this observation. Consider circumstances under which you would expect to see different results. 
</div></li></ul></li></ol>

Eusocialité et division du travail

Simulating Eusocial and Solitary Behavior
ExpandNote: In this simulation, you will portray either a eusocial or solitary animal. The goal of this ...

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Extinction

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Diversity and Extinction during the Paleogene Epoch
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">Begin this procedure by reading the extinction reading supplement that has been printed out for you. <br /><strong>NOTE:</strong> Alternatively, you may download the reading supplement at the link below.&nbsp; <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/24/Lab_20_Reading Supplement.docx" style="display:block;margin:20px;" target="_blank">Click here to download the extinction reading supplement</a>
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Using the information contained in the extinction reading supplements pertaining to the taxa of interest and the Chicxulub impact event, make predictions for each taxon listed in Table 1. Consider whether diversity in each taxon increased, decreased, or stayed the same immediately following the Cretaceous-Paleogene boundary and later on in the Paleogene epoch. <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/24/Table_1_Extinction.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Then, fill out the reasons for each of your predictions in the Contributing Factors column. HYPOTHESES: The experimental hypothesis is that many of the different taxa will show changes in diversity after the Cretaceous-Paleogene event, and again at the end of the Paleogene, with some increasing in diversity, while others decrease. The null hypothesis is that there will be no changes in diversity between taxa following the Cretaceous-Paleogene event, or at the end of the Paleogene.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Gather diversity data by going to the Paleobiology Database: <a href="http://www.paleobiodb.org" target="_blank">www.paleobiodb.org</a>.
</div></li><li data-sub-note-item="1-5"><div class="lab-step">In the center of the screen, click the yellow box labeled Download Data. Under the italicized heading, &#8220;What do you want to download?&#8221;, select Diversity over time on the left side and Comma-separated values on the right side.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">Scroll down to the heading &#8220;Select by taxonomy&#8221;.
</div></li><li data-sub-note-item="1-7"><div class="lab-step">In the first box labeled 'Taxon or taxa to include', type in the name of the taxon that data is being gathered on.  NOTE: Ensure the spelling is correct.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">Now, go to the dropdown menu right below that box labeled &#8220;Taxonomic resolution&#8221;, and select genera.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">Under the next heading, Select by time, type Maastrichtian into the first box and Chattian in the box directly below. Make sure the dropdown menu labeled Time rule is set to major and the Temporal resolution is set to stage.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">Select &#8220;Assume extant taxa range through to present&#8221;. Scroll back up to the middle of the page and click download. A save window will open.
</div></li><li data-sub-note-item="1-11"><div class="lab-step">Save the .csv file to a safe and accessible place and rename it to make it easy to identify.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">Open the file and scroll down to the main dataset under Records.  NOTE: The data are arranged in reverse time order by geological stage. The second column, interval_name, gives the accepted name of the stage in question. The next two columns give the appropriate dates of the stage in millions of years before the present. The final column, number of occurrences, gives a total count of the genera extant during that geological stage as determined from occurrence of fossils.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">To more easily work with this data, copy and paste each column into a new sheet. Be sure to label this sheet with the taxon in question, the data and time the data were obtained, and the data source.
</div></li><li data-sub-note-item="1-14"><div class="lab-step">Repeat this process for each of the taxa in Table 1 (steps 4 &#8211; 12). NOTE: Data from multiple taxa can be kept on the same sheet, so long as they are kept distinct and labeled appropriately.
</div></li><li data-sub-note-item="1-15"><div class="lab-step">To create line plots for each of the taxa showing the change in diversity over time, select the max_ma column and the number of occurrences column simultaneously.
</div></li><li data-sub-note-item="1-16"><div class="lab-step">In Excel, select Insert from the top toolbar and find the section labeled Charts. Select the bottom center icon, Insert Scatter Chart.
</div></li><li data-sub-note-item="1-17"><div class="lab-step">Then, select the Scatter with Straight Lines and Markers and a graph should appear. NOTE: Since the axis of this graph is in units of millions of years ago, the axis is in the reverse direction of time when put in numerical order.
</div></li><li data-sub-note-item="1-18"><div class="lab-step">To fix this, click on the green plus sign in the top-right corner of the graph and hover over Axes. This should reveal a small black arrow. Click the arrow to open up a small menu and select More Options.
</div></li><li data-sub-note-item="1-19"><div class="lab-step">This will open the Axis Options menu. Under Axis Options, click the box next to Values in reverse order. NOTE: It is also possible to change the axis scales from this menu, which can be used to eliminate the excess time that is not being analyzed in this lab. Keep any changes consistent between different graphs.
</div></li><li data-sub-note-item="1-20"><div class="lab-step">Double-click on the title at the top of the graph and change it to the taxon being represented.
</div></li><li data-sub-note-item="1-21"><div class="lab-step">Make a separate graph for each of the taxa in Table 1. Keep them organized and in one location. A separate sheet for graphs is recommended.
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">For each graph, identify the location of the Cretaceous-Paleogene boundary and draw a vertical line through the graph at this point.
</div></li><li data-sub-note-item="2-2"><div class="lab-step">Using the information from the graphs, fill out Table 2. In some cases, it may be helpful to go back to the original dataset and compare actual values, particularly when they are small. <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/24/Table_2_Extinction.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 2</a>
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Compare these values to the predictions made in Table 1 and discuss if the original contributing factors are still likely candidates.
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Using the dataset, calculate the percentage of total taxa that went extinct over the Cretaceous-Paleogene boundary using this equation.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">There is an event in the middle of the Paleogene known as the Paleocene-Eocene Thermal Maximum about 55.5 million years ago. This represents a high point in temperature during the Paleogene epoch at approximately 8 &#176;C higher than today&#39;s average temperature. Does this point seem to have an effect on diversity for any of the taxa? If yes, then which ones?
</div></li></ul></li></ol>

Extinction: Diversity and Extinction during the Paleogene Epoch - Procedure

Diversity and Extinction during the Paleogene Epoch
ExpandBegin this procedure by reading the extinction reading supplement that has been printed out for ...

Group Behavior

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">The Hawk-Dove Game
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">NOTE: In this activity, you will play the hawk and dove game with a single partner and then with multiple partners to observe hypothetical costs and benefits of the antagonist or cooperative behavior respectively. 
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Before the activity starts, review the cost-benefit table so that you understand how to score the game. <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/33/Table_1_Group_behavior.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="1-3"><div class="lab-step">HYPOTHESES: The experimental hypothesis for this exercise could be that the dove strategy will become more frequent between repeated partners, and the hawk strategy will become more frequent when interactions are with a variety of partners. The null hypothesis could be that there will be no change in strategy over time with repeat or different partner combinations. NOTE: Benefit can be determined by looking at the left column and choosing the row that corresponds to the card you played. The box that corresponds to the choice of your partner can be found in the top row. For the purposes of this game, B equals four and C equals three. So depending on the cards played, player one here, which is you, would gain a score of two, four, zero or one half. 
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Collect a set of two game cards. 
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Take out the cards labeled hawk and dove and place them face down on the table or conceal them in your hands. 
</div></li><li data-sub-note-item="1-6"><div class="lab-step">When the instructor gives the signal show either of the two cards to the student sitting across from you. Try to strategize how to receive the highest benefit from every interaction on your own but do not communicate with your partner. 
</div></li><li data-sub-note-item="1-7"><div class="lab-step">In the Single Partner Recording Table (Table 2) provided by your instructor, note the cards played as well as the benefit you received for that round.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">Repeat showing cards to the same partner and determining benefit on your instructor&#39;s signal for a total of 15 rounds.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">At the end of those rounds, the student with the highest total benefit value was determined to be the &#8220;winner&#8221;, or the most fit.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">As a class, determine the percentages of hawks and doves played as well as the average benefit received for each round, using this formula: Class average benefit=(sum total benefit)/(number of players)
</div></li><li data-sub-note-item="1-11"><div class="lab-step">For the second game, and then for each round of play, one row of students should rotate to their right, leaving all players with a new partner.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">Continue playing for 15 rounds or until students end up back in their starting positions, recording the data in the Multiple Partner Recording Table (Table 3) given to you by your instructor.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">For each round, determine the percentages of hawks and doves played that round, as well as the average benefit received.
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Cheating and Cooperation Exercise
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">NOTE: In this activity, you will exchange benefits, represented by colored or similar items, with your classmates. In this simulation, a cheater is defined as a person who gives fewer benefits than they receive. During this activity, you will observe the frequency of cheating behavior over time. 
</div></li><li data-sub-note-item="2-2"><div class="lab-step">HYPOTHESES: The experimental hypothesis is that cheaters will receive fewer benefits over time and cooperators will continue to provide equal benefits to one another. The null hypothesis is that the frequency of cheaters and cooperators does not change over time. 
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Each person should collect beads of one color to represent a tangible benefit, as well as one paper bag and a three-ring binder.
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Get into a group of three so that all members have objects of the same color.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">Now find another group with a different color to pair with. In each round, partners will exchange benefits without knowing what they are receiving from their partner and without discussion within their group.  NOTE: Benefits of a different color from your starting color are worth twice as much.
</div></li><li data-sub-note-item="2-6"><div class="lab-step">Turn face to face with a member from the other group while still being able to conceal the objects in your possession.  TIP:<strong> </strong>Setting up a screen using a notebook or sitting behind a desk can be helpful here.
</div></li><li data-sub-note-item="2-7"><div class="lab-step">When given a signal from the instructor, place zero to two benefits into the paper bag and pass it to your partner.
</div></li><li data-sub-note-item="2-8"><div class="lab-step">Simultaneously, receive the bag from your partner and then remove the benefits from the bag.
</div></li><li data-sub-note-item="2-9"><div class="lab-step">Make a note of how many benefits you gave away and how many you received in the Cheating and Cooperation Table (Table 4) provided by your instructor.
</div></li><li data-sub-note-item="2-10"><div class="lab-step">Turn to a new member from the other group and repeat the exchange.
</div></li><li data-sub-note-item="2-11"><div class="lab-step">Rotate through all of the members of the other group for as many rounds as the instructor determines - which will not be revealed until the game ends so as not to alter player behavior.
</div></li><li data-sub-note-item="2-12"><div class="lab-step">Once the game has ended, note for each round in the cheating and cooperation table whether you gave more than your partner, received more from them or if you gave the same amount.
</div></li><li data-sub-note-item="2-13"><div class="lab-step">Now total up all of the benefits in your possession, with benefits you&#39;ve received from the other group being worth twice as much.
</div></li><li data-sub-note-item="2-14"><div class="lab-step">For each round, the whole class should total up the number of cheaters - with cheaters defined as those who gave less than they received.
</div></li></ul></li><li data-note-item="3" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="3-1"><div class="lab-step">For both the single partner hawk-dove game and the multiple partners hawk-dove game, use the whole class data to plot the percentages as two separate lines - one for the percentage of hawks, and one for the percentage of doves, for each of the 15 rounds.
</div></li><li data-sub-note-item="3-2"><div class="lab-step">Take note of whether the cards played changed as more rounds were played.
</div></li><li data-sub-note-item="3-3"><div class="lab-step">Manipulate the values for B and C to see if you can find the point at which values of B and C would render the hawk strategy no longer effective (this would be the point when there is no benefit to choosing the hawk strategy over always choosing the dove strategy).
</div></li><li data-sub-note-item="3-4"><div class="lab-step">As a class, use the data from the cheating and cooperation activity to make a graph showing the percentage of rounds each individual player cheated versus the amount of benefits they ended with.
</div></li><li data-sub-note-item="3-5"><div class="lab-step">Consider whether it is better to be a cheater or a cooperator in this scenario and discuss as a class what makes this scenario different from the hawk-dove game.
</div></li><li data-sub-note-item="3-6"><div class="lab-step">Now, use the class data to graph the percentage of cheaters against the number of rounds, and look for any trends over time.
</div></li><li data-sub-note-item="3-7"><div class="lab-step">Consider which type of strategy would most likely evolve in a setting where partners interact repeatedly.
</div></li><li data-sub-note-item="3-8"><div class="lab-step">Then, note which tactic might be beneficial for a species that relies on cooperation. 
</div></li><li data-sub-note-item="3-9"><div class="lab-step">Discuss as a class what would likely happen if you increased or decreased the relative value of the benefits you receive.
</div></li></ul></li></ol>

Group Behavior: Hawk-Dove Game and Trading Exercise - Procedure

Comportement de groupe

The Hawk-Dove Game
ExpandNOTE: In this activity, you will play the hawk and dove game with a single partner and then with multiple partners to observe ...

Optimal Foraging

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Simulating Foraging with Artificial Habitats and Prey
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">NOTE: The foragers will hunt for prey represented by pinto beans in four buckets of rice with varying prey densities. Without knowing what these densities are, foragers must obtain as many prey items as possible in as little time as possible. 
</div></li><li data-sub-note-item="1-2"><div class="lab-step">HYPOTHESES: In this experiment, the experimental hypothesis could be that foragers will catch the most prey in the higher prey density bucket and also spend the most time foraging there.  The null hypothesis would then be that foragers will catch an equal number of prey in each bucket and that foragers will spend an equal amount of time foraging in each patch. 
</div></li><li data-sub-note-item="1-3"><div class="lab-step">To begin the foraging activity, record the names and role of each participant at the top of the student data collection sheet.  NOTE: Before starting the experiment, the forager is allowed to become familiar with the foraging process &#8211; the following steps are a practice round. 
</div></li><li data-sub-note-item="1-4"><div class="lab-step">The forager should kneel or sit in front of the average density bucket. 
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Once the timer says start, the forager may begin looking for the pinto beans representing the prey. The forager can spend as much time as they like foraging in this bucket. 
</div></li><li data-sub-note-item="1-6"><div class="lab-step">Once a prey item is located, the forager must signal that one has been found and place the prey in the cup next to the bucket.
</div></li><li data-sub-note-item="1-7"><div class="lab-step">Once they believe they have acquired most of the prey in the patch, they should tell the timer to stop the time and the practice round is over. 
</div></li><li data-sub-note-item="1-8"><div class="lab-step">To begin the simulation proper, the forager should sit or kneel in front of bucket A. 
</div></li><li data-sub-note-item="1-9"><div class="lab-step">The timer must be ready to start the stopwatch. 
</div></li><li data-sub-note-item="1-10"><div class="lab-step">The recorder should be ready to record the time each prey item is located, in addition to the time that the forager arrived at and left each bucket. 
</div></li><li data-sub-note-item="1-11"><div class="lab-step">When all parties are ready, the timer should start the stopwatch and say &#8220;start&#8221;,  and the forager should begin foraging. NOTE: The stopwatch will run through the rest of the round for buckets B and C.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">As the forager signals finding pinto beans and places them in the cup next to the bucket, the timer should tell the recorder the time.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">The recorder should then write the time in the student data collection sheet.  <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/34/Table_1_Optimal_foraging.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="1-14"><div class="lab-step">Once the forager has decided to move on to the next bucket, they should tell the timer &#8220;done&#8221;, and begin moving to the next patch. 
</div></li><li data-sub-note-item="1-15"><div class="lab-step">The recorder should record the time the forager left and the time they arrived at bucket B in the student data collection sheet.
</div></li><li data-sub-note-item="1-16"><div class="lab-step">Repeat the same procedure for buckets B and C. Once the forager has completed the activity, it is time for the next forager to begin using the same procedure. 
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">Before performing any data analysis, review the data collection sheet and compile your individual data for captured prey, foraging time, and travel time for each bucket in your student calculations table. <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/34/Table_2_Optimal_foraging.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 2</a>
</div></li><li data-sub-note-item="2-2"><div class="lab-step">After this, calculate your individual capture rate for each bucket by dividing the number of prey captured by the sum of the foraging time and travel time and record these values in your table. Individual capture rate =  Number of prey captured / (foraging time + travel time)
</div></li><li data-sub-note-item="2-3"><div class="lab-step">To calculate your Giving-Up-Time or a GUT for each bucket, subtract the time that the last prey item was acquired from the time you left the bucket.  GUT = time forager left bucket  -  time last prey item acquired
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Next, calculate the mean GUT for your foraging group and record the values in your table.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">Finally, calculate your scaled GUT for each bucket by dividing the bucket GUT by your group&#39;s mean GUT. Scaled GUT =  Bucket GUT / Group mean GUT NOTE: The scaled GUT will allow class data to be pooled later on without differences in individual foragers skewing the data. 
</div></li><li data-sub-note-item="2-6"><div class="lab-step">The instructor should now compile the data into the classroom spreadsheet.  <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/34/Table_3_Optimal_foraging.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 3</a>
</div></li><li data-sub-note-item="2-7"><div class="lab-step">Plot a bar graph of the average number of prey collected in each bucket. On the x-axis, A should represent the low prey density bucket, B should represent the medium prey density bucket, and C the high prey density bucket. Plot the y-axis as the number of prey items caught. 
</div></li><li data-sub-note-item="2-8"><div class="lab-step">Next, plot the graph of the class average scaled GUT, where the x-axis represents the buckets with varying levels of prey density and the y-axis shows the values for the average scaled GUT. 
</div></li><li data-sub-note-item="2-9"><div class="lab-step">Plot a third graph of the average time spent foraging in each bucket. 
</div></li><li data-sub-note-item="2-10"><div class="lab-step">Now review the Marginal Value Theorem (MVT) from the concepts video and examine the three graphs that you generated from your class data. Take note of whether the graphs conform to the predictions of MVT. 
</div></li></ul></li></ol>

Optimal Foraging: Foraging with Artificial Habitats and Prey - Procedure

Alimentation optimale

Simulating Foraging with Artificial Habitats and Prey
ExpandNOTE: The foragers will hunt for prey represented by pinto beans in four buckets of rice with ...

Sexual Selection and Mate Choice

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Sexual Selection Class Simulation
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">Note: In this activity, you and your classmates will portray a sexually reproducing population consisting of an equal number of male and female animals. You will simulate several different mating scenarios to determine how relative quality, attractiveness, sex, and parental commitment affect mate choice and reproductive success. The goal of this activity is to maximize your progeny. 
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Hypotheses: There are several overall hypotheses for female and male behavior for this activity. The main experimental hypothesis for female behavior is that females will mate with males of high quality more frequently than those of low quality, yielding a higher reproductive success. The null hypothesis is that females will not demonstrate preference towards high- or low-quality males in any of the four rounds of mating. For males, one experimental hypothesis is that males with a higher visible score will have greater reproductive success. Another could be that males will be more selective for females in scenarios in which they join females to care for offspring as opposed to scenarios in which they exhibit no parental commitment. The null hypothesis for male behavior might be that males will not demonstrate preference towards high- or low-quality females in any of the four rounds of mating. 
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Activity Overview: To begin, each student will be assigned a sex as well as a relative quality and attractiveness score. Remember - the goal is to maximize your reproductive success in each round. You do this by mating with partners of the highest possible quality which is rated on a scale of one to three with three being the highest possible score. Attractiveness scores, which follow the previously described scoring paradigm, correlate with quality but do not exactly predict the score. Though useful, they are not a perfect way to choose the best mate.  If you are assigned a male ID holder, you will have 16 gametes. However, if you are assigned a female ID holder, you will only have four. A successful mating occurs when one sperm and one egg are paper-clipped together and deposited at the fertilization area. 
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Note - Rules of the activity: 
<ul>
	<li>Assigned male and female identities for these experiments are not representative of students&#39; personal gender identities. </li>
	<li>Running is not permitted. </li>
	<li>Talking is not permitted.</li>
	<li>Hidden values cannot be shared but individuals can attempt to hide their visible scores. </li>
	<li>Respect the space around each individual and remain an arm&#39;s length away. </li>
	<li>Offspring will only be counted towards an individual score if both gametes are paper-clipped together and dropped off in the designated fertilization area before the end of the two-minute round. </li>
</ul>
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Round 1 &#8211; Hidden Quality Score
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">To begin the first simulation, take the clip-on ID holder you were randomly assigned and make sure it contains four gametes if you are assigned female or sixteen gametes if male. Males should also have a strip of white paper and two paperclips. 
</div></li><li data-sub-note-item="2-2"><div class="lab-step">Next, males should paperclip the white strip of paper over their quality score to hide it, but keep the attractiveness score visible. 
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Record your ID number for round one in table two.  <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/35/Table_2_sexual_selection.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 2</a>
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Next, clip on the ID holder and move to the designated mating area. 
</div></li><li data-sub-note-item="2-5"><div class="lab-step">When the instructor says begin, you may commence the mating simulation. You will have exactly two minutes to produce as many offspring as possible. Males may freely give their sperm to females, and females may choose to use these sperm immediately after which they would walk to the fertilization area and paperclip it to one of their eggs, or they may choose to wait until they receive other sperm to do so. 
</div></li><li data-sub-note-item="2-6"><div class="lab-step">Once the gametes have been deposited in the fertilization area, females may resume mating. 
</div></li><li data-sub-note-item="2-7"><div class="lab-step">When the two minutes have elapsed, all matings must stop and any gametes not in the fertilization area at this time will not be counted. 
</div></li><li data-sub-note-item="2-8"><div class="lab-step">The instructor should now tally all of the matings and record the numbers of the individuals who produced each offspring.
</div></li><li data-sub-note-item="2-9"><div class="lab-step">Now, find all the gametes that came with your ID holder and repackage them for the next round. 
</div></li></ul></li><li data-note-item="3" data-parent-collapse="">Round 2 &#8211; Hidden Attractiveness Score
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="3-1"><div class="lab-step">For the second round, obtain a new randomly assigned ID holder and again ensure it contains the proper number of gametes. 
</div></li><li data-sub-note-item="3-2"><div class="lab-step">Next, males should use the paperclip and strip of white paper to hide their attractiveness score (instead of the quality score, which was covered in round one).
</div></li><li data-sub-note-item="3-3"><div class="lab-step">Record the ID number of your clip in table two under round two.  Note: The mating simulation process for round two will be the same as round one.
</div></li><li data-sub-note-item="3-4"><div class="lab-step">Move to the designated mating area and with for the instructor to signal the start of the round. As before, males may freely give away their sperm while females will choose to use it now or wait for different sperm. When a female decides to fertilize an egg, she will walk to the fertilization area and paperclip the gametes together. 
</div></li><li data-sub-note-item="3-5"><div class="lab-step">Proceed with the simulation for two minutes, and at the signal from the instructor all mating activity should stop. 
</div></li><li data-sub-note-item="3-6"><div class="lab-step">The instructor should now tally all of the matings from this second round.
</div></li><li data-sub-note-item="3-7"><div class="lab-step">Now, find and return the gametes to your ID holder, and then return the holder to the instructor.
</div></li></ul></li><li data-note-item="4" data-parent-collapse="">Round 3 &#8211; Visible Quality and Attractiveness Scores
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="4-1"><div class="lab-step">For the third simulation, you should again obtain a new clip-on ID holder and check that it contains the appropriate number of gametes. Record the ID number of your clip in table two.
</div></li><li data-sub-note-item="4-2"><div class="lab-step">For this round, leave both attractiveness and quality scores visible on male IDs. Note: The mating simulation process for round three will be the same as the previous two rounds.
</div></li><li data-sub-note-item="4-3"><div class="lab-step">Move to the mating area and wait for the signal to begin the simulation.
</div></li><li data-sub-note-item="4-4"><div class="lab-step">Once the instructor starts the timer and gives the signal, commence mating. As before, males are allowed to freely give away their sperm to females and females may use the sperm immediately or wait for different sperm. Again, fertilized eggs only count if placed in the fertilization area. 
</div></li><li data-sub-note-item="4-5"><div class="lab-step">After the two-minute time limit, the instructor should tally all matings. 
</div></li><li data-sub-note-item="4-6"><div class="lab-step">Now, find and return the gametes to your ID holder, and then return the holder to the instructor.
</div></li></ul></li><li data-note-item="5" data-parent-collapse="">Round 4 &#8211; Increased Male Parental Care
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="5-1"><div class="lab-step">In the final round, males will again leave their attractiveness and quality scores visible. 
</div></li><li data-sub-note-item="5-2"><div class="lab-step">Obtain an ID holder and ensure it contains the appropriate number of gametes. 
</div></li><li data-sub-note-item="5-3"><div class="lab-step">Clip on the ID holder and move to the mating area. Note: As before, males may freely give away their sperm to females. However, in this round, once a female chooses to mate with a male, both the male and female will walk to the fertilization area to paperclip their gametes together. After placing the paper-clipped gametes on the table, both male and female actors may return to the mating area. 
</div></li><li data-sub-note-item="5-4"><div class="lab-step">The instructor should signal the start of the round and begin the timer &#8211; at this point participants can begin the simulation.
</div></li><li data-sub-note-item="5-5"><div class="lab-step">Once the two-minute time limit is up, all matings must stop. 
</div></li><li data-sub-note-item="5-6"><div class="lab-step">The instructor should tally all mating events.
</div></li><li data-sub-note-item="5-7"><div class="lab-step">Find and return the gametes to your ID holder. Give your ID holder to the instructor and notify them if any gametes or supplies are missing. 
</div></li></ul></li><li data-note-item="6" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="6-1"><div class="lab-step">To analyze the data generated during the mating activities, first split up into groups of four. 
</div></li><li data-sub-note-item="6-2"><div class="lab-step">Collect the class data from the instructor for ONE of the four rounds of mating. Note: In this activity, there were several types of females and males distinguished by different letters. These letter types correspond to specific combinations of quality and attractiveness scores. In the compiled data, the average number of matings and reproductive success has already been sorted by letter type for you by the instructor. 
</div></li><li data-sub-note-item="6-3"><div class="lab-step">Use these data to generate four graphs for the round you were assigned. First plot two graphs for the average number of matings against female and male type. 
</div></li><li data-sub-note-item="6-4"><div class="lab-step">Then plot the reproductive success for males and females against male or female type, giving a total of four graphs.
</div></li><li data-sub-note-item="6-5"><div class="lab-step">Once these graphs are complete, each group should present their data to the class, making sure to state the original hypothesis for your assigned round and whether or not the hypothesis was upheld.
</div></li><li data-sub-note-item="6-6"><div class="lab-step">After each group presents, discuss the overall results of the four rounds together. 
</div></li><li data-sub-note-item="6-7"><div class="lab-step">Note the affect that hiding the quality score had on the overall quality of mates chosen.
</div></li><li data-sub-note-item="6-8"><div class="lab-step">Note how hiding or revealing the attractiveness score affected the results.
</div></li><li data-sub-note-item="6-9"><div class="lab-step">Discuss the effect of male parental investment on the number and overall quality of mating pairs.
</div></li></ul></li></ol>

Sélection sexuelle et choix du partenaire

Sexual Selection Class Simulation
ExpandNote: In this activity, you and your classmates will portray a sexually reproducing population consisting of an ...

Evolutionary Relationships

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Forming an Evolutionary Hypothesis
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">NOTE: A cladogram is an important tool for forming an evolutionary hypothesis. A cladogram is a tree-shaped chart used to depict the hypothetical genealogical relationships between species. The tips or leaves of the chart represent specific species and the branches of the tree are different lengths. The different lengths represent the degree of change between each of the species. The common ancestor of all of the species that a specific line branches from is located at a node, where the branches intersect. Species that share a node are called a sister group.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">To begin, look at the provided blank cladogram and make a hypothesis about where the assigned animals should be placed on the tree. If a blank cladogram has not been provided please <a target="_blank" href="/files/ftp_upload/10562/Blank_Cladogram.png">download one here</a>.
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Next, observe the image of the fossilized animal.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Using the morphology, or physical characteristics, of the fossil, make a hypothesis about where on your cladogram it should be placed. Add a new line or mark to indicate your proposed position for the fossil.
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Comparing Gene Sequences Using BLAST
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">NOTE: Historically, cladograms have been constructed through the comparison of morphology. Now, genetic sequences can also be compared between species of interest to construct cladograms. DNA sequences are not usually preserved in fossils, so for this lab you will use the BLAST database to compare the DNA sequences of living species that are closely related to the fossil to thousands of other living species.
</div></li><li data-sub-note-item="2-2"><div class="lab-step">Before beginning this lab, your instructor will have downloaded the three preserved gene sequences to a folder on your desktop.
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Navigate to the BLAST homepage, which the instructor should have left open in your browser, and click on Saved Strategies from the menu at the top of the page.
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Click Open on the Evolutionary_Relationships_Gene1.txt file.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">Then, click View to go to the Standard Nucleotide BLAST search page. You should be able to see the DNA sequence in the Query Sequence box at the top-right of the screen.
</div></li><li data-sub-note-item="2-6"><div class="lab-step">Scroll to the bottom of the screen and click the BLAST button. Note: It will take a few moments to process and analyze the data. 
</div></li><li data-sub-note-item="2-7"><div class="lab-step">When the data has been processed, a graphic summary will appear.  NOTE: Your query sequence is represented by the blue line at the top of the box. Each of the lines below the blue line represents another sequence in the BLAST database that matches your query. The length and location of these bars represent where and how much of the sequence match up to the query. The color of the bar represents its score, or how identical the sequence is to the query. Below the graphic summary is the Sequences producing significant alignments list, which contains descriptions of the DNA sequences retrieved from the database that most closely align with the query sentence. These are listed in descending order, from the most similar at the top to the least similar at the bottom. On the right, there are several statistics on how closely related each database sequence is to the experimental sequence. The higher the Max, Total, Query Coverage, and Identity scores are, the more similar the query and retrieved sequences are to each other. Similarly, the lower the E value number, the less likely the sequences match was found by random chance and more significantly the alignment is accurate. An E value of 0 indicates a highly significant match.
</div></li><li data-sub-note-item="2-8"><div class="lab-step">Click on the name of the description of the most similar alignment listed. This will take you further down the page to the exact DNA sequence alignment between the retrieved sequence and the query sequence.
</div></li><li data-sub-note-item="2-9"><div class="lab-step">Click on the Sequence ID number. This will open a new tab with more specific information on the retrieved gene sequence.
</div></li><li data-sub-note-item="2-10"><div class="lab-step">Identify and record the scientific and common names of the organism, which should be listed next to Source.
</div></li><li data-sub-note-item="2-11"><div class="lab-step">Identify and record the protein that the gene codes for, which should be listed next to Definition.
</div></li><li data-sub-note-item="2-12"><div class="lab-step">Close the tab and hit Back to return to the Sequences producing significant alignments list.
</div></li><li data-sub-note-item="2-13"><div class="lab-step">Then, repeat steps 7 &#8211; 9 for the next most similar sequences.
</div></li><li data-sub-note-item="2-14"><div class="lab-step">After collecting several species names, return to the Sequences producing significant alignments list and click Select: All to check all of the boxes next to the names of each listed alignment sequence.
</div></li><li data-sub-note-item="2-15"><div class="lab-step">Click on Distance of tree results to create a phylogram based on the similarity of all of the BLAST result gene sequences to the query gene sequence.  Note: Your query fossil relative sequence will be highlighted in yellow.
</div></li><li data-sub-note-item="2-16"><div class="lab-step">Record your sequence&#8217;s location in relation to the other taxon groups shown in the tree.
</div></li><li data-sub-note-item="2-17"><div class="lab-step">Finally, return to the Saved Strategies tab and upload the next saved gene sequence.
</div></li><li data-sub-note-item="2-18"><div class="lab-step">Query the remaining two fossil relative DNA sequences as previously demonstrated (steps 1 &#8211; 16).
</div></li></ul></li><li data-note-item="3" data-parent-collapse="">Data Analysis
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="3-1"><div class="lab-step">Based on your gene sequence results, come up with a second hypothesis about where your fossil specimen fit in the original cladogram.
</div></li><li data-sub-note-item="3-2"><div class="lab-step">Compare this placement with your first hypothesis.
</div></li><li data-sub-note-item="3-3"><div class="lab-step">Compare your tree with your classmates&#8217;. If any of your classmates put the fossil on a different branch, ask them how they came to that decision.
</div></li></ul></li></ol>

Evolutionary Relationships: Using BLAST to Test Evolutionary Hypotheses - Procedure

Relations évolutives

Forming an Evolutionary Hypothesis
ExpandNOTE: A cladogram is an important tool for forming an evolutionary hypothesis. A cladogram is a tree-shaped chart ...

Evolution

Energy Dynamics

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Caterpillar Energy Dynamics
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">NOTE: In this lab you will grow caterpillars in conditions with and without food to examine the transfer of biomass in a typical trophic system.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Weigh and record the wet mass of enough leaves of cabbage to line the bottom of a plastic tub.
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Then, collect two batches of five caterpillars from their cabbage habitat, and weigh and record the wet mass of each batch separately in individual weigh boats. Make sure to tare the balance before each measurement. HYPOTHESES: The experimental hypothesis is that only a fraction of energy will be transferred between the trophic levels of the cabbage and the caterpillars and a significant amount will be lost as waste and heat energy. The null hypothesis is that there will be no significant difference between the energy input from the cabbage, and the obtained energy stored as biomass in the caterpillars.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Place the weighed cabbage and five caterpillars in a plastic tub lined with damp paper towels, leaving the lid slightly cracked open for ventilation, but not wide enough for the animals to escape.
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Place the other five caterpillars in a second clean container prepared the same way, but with no cabbage.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">After three days, transfer the caterpillars to new weigh boats, and weigh and record the final wet mass of both groups of caterpillars and the cabbage.
</div></li><li data-sub-note-item="1-7"><div class="lab-step">Then place the caterpillar waste, or frass, and cabbage into two separate dishes, and put both dishes into a 37 &#176;C incubator to dry for 48 hours.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">Euthanize the weighed caterpillars by putting them into a minus 20 &#176;C freezer for 24 hours.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">Then, transfer the dishes to a 37 &#176;C incubator for 48 hours.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">After drying, weigh and record the dry mass of the uneaten cabbage, the two groups of caterpillars, and the frass, and use these data to calculate the percent biomass of the caterpillars.
</div></li><li data-sub-note-item="1-11"><div class="lab-step">Finally, discard all of the dried organisms and plates into the hazardous waste bin, and wipe down your workspace with 70% ethanol.
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">Take a look at the data you collected. Ensure the initial wet mass, the final wet mass, and the final dry mass columns are accurately filled out in your table. <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/13/Table_1_Energy_Dynamics.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="2-2"><div class="lab-step">NOTE: Remember an object&#39;s biomass is equal to its dry mass. Therefore, percent biomass for each group is the final dry mass divided by the final wet mass times 100. For example, obtain the percent biomass of the cabbage by dividing the final dry mass by the final wet mass and multiplying by 100. This means that approximately 15% of the cabbage&#39;s total weight is biomass.
</div></li><li data-sub-note-item="2-3"><div class="lab-step">After this, estimate the initial biomass of the cabbage and caterpillars by multiplying the percent biomass by the initial wet mass, and put the values in this new table. NOTE: Remember, biomass equals dry mass. Therefore, the final dry mass is equal to the final biomass of each group.
</div></li><li data-sub-note-item="2-4"><div class="lab-step">To calculate the approximate initial and final energy in the form of kilocalories within the cabbage, caterpillars, and frass, multiply the biomass values recorded in your table by the conversions, and record the calculated values in the table. <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/13/Table_2_Energy_Dynamics.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Table 2</a>
</div></li><li data-sub-note-item="2-5"><div class="lab-step">After this, subtract the initial energy from the final energy to obtain the change in energy for each group.
</div></li><li data-sub-note-item="2-6"><div class="lab-step">NOTE: The negative sign denotes loss in energy, and positive indicates gain.
</div></li><li data-sub-note-item="2-7"><div class="lab-step">Using your data table, calculate the energy in kilocalories that the fed caterpillars lost to respiration. The formula is the energy gained from cabbage, which is the positive of the energy lost by cabbage, minus the biomass gained from cabbage, minus the energy lost via frass. <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/13/Table_3_Energy_Dynamics.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Table 3</a>
</div></li><li data-sub-note-item="2-8"><div class="lab-step">Then, repeat the same calculation for the unfed group of caterpillars. Make another column in the table and note this down.
</div></li><li data-sub-note-item="2-9"><div class="lab-step">Finally, add up all of the energy gained via biomass and cabbage consumption, and the energy lost via frass and respiration for each group of caterpillars. NOTE: For both groups of caterpillars the net energy is zero, meaning that this experiment obeyed the first law of thermodynamics.
</div></li></ul></li></ol>

Studying Energy Dynamics and Productivity - Procedure

Dynamique de l’énergie

Caterpillar Energy Dynamics
ExpandNOTE: In this lab you will grow caterpillars in conditions with and without food to examine the transfer of biomass in a ...

Animal Behavior

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Making Choice Chambers
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">Before beginning the experiments, use one of the Sharpies from the lab table to trace a line around the circumference of the bottom of both bottles. One line should be 1 cm from the base of the bottle and the other should be 1.5 cm from the base of the bottle.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Use a razor blade to make a small cut in each bottle at the mark. 
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Then, insert the scissors and carefully cut along the line until the bottoms of the bottles are removed completely.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Fit one bottle bottom into the other.
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Tape the bottles together to make a secure chamber.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">Use the razor blade and scissors to poke a hole into the center of the chamber. 
</div></li><li data-sub-note-item="1-7"><div class="lab-step">Take a piece of tape and fold the edge onto itself to make a tab and place the tape over the hole.  Note: The tab helps with easy removal and reattachment of the tape to the chamber.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">Use the Sharpie to label one side of the chamber A and the other side B.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">Upon receiving the colony of <em>Drosophila</em>, perform a count to make sure there are 40 living individuals in the vial.
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Geotaxis
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">To perform a geotaxis assay, first attach a clean, empty bottle cap to each end of the choice chamber and turn the fly vial upside down onto its lid.
</div></li><li data-sub-note-item="2-2"><div class="lab-step">Open the tape flap in the center of the choice chamber.
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Insert the funnel into the hole and tap all of the flies into the chamber. HYPOTHESES: The alternate hypothesis is that more flies will be moving against gravity, or up, regardless of the orientation of the choice chamber. Alternatively, if the flies are positively geotactic, then more flies will move down, or with gravity. The null hypothesis is that the flies will have no preference with regard to gravity and will move randomly within the chamber. 
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Once the <em>Drosophila</em> are in the chamber, close the tape flap, rotate the chamber so that it stands vertically with side A on the bottom, and start the timer.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">Immediately, count the number of <em>Drosophila</em> that are moving up and the number that are moving down. Record these data for time point 0 in the table. 
</div></li><li data-sub-note-item="2-6"><div class="lab-step">After 30 seconds, rotate the chamber so that side B is on the bottom and count the number of <em>Drosophila</em> that are moving up or down. Record these data for time point 30 in the table.
</div></li><li data-sub-note-item="2-7"><div class="lab-step">After 60 seconds, rotate the chamber so that side A is on the bottom again and record the number of moving flies for time point 60.  <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/15/Table_1_Animal_behavior.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="2-8"><div class="lab-step">Hold the chamber over the fly vial and carefully open the cap to return all of the <em>Drosophila</em> back to their empty vial. 
</div></li></ul></li><li data-note-item="3" data-parent-collapse="">Phototaxis
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="3-1"><div class="lab-step">To perform a phototaxis analysis, first cover side A of the choice chamber with tin foil, taking care that the foil reaches to the exact center between the two sides. 
</div></li><li data-sub-note-item="3-2"><div class="lab-step">Ensure the caps are secured on both ends of the chamber.  HYPOTHESES: In this exercise, the alternative hypothesis is that more flies will be found in the light side of the choice chamber, if the flues are attracted to light, or on the dark side if they are repelled by light. The null hypothesis is that <em>Drosophila</em> will have no preference with regard to either stimulus. Therefore, equal numbers of flies will be found on either side of the choice chamber.
</div></li><li data-sub-note-item="3-3"><div class="lab-step">Open the tape flap in the center of the choice chamber, insert the funnel into the hole, and tap all 40 flies into the chamber as previously described.
</div></li><li data-sub-note-item="3-4"><div class="lab-step">Set the timer to sound an alarm at 10 minutes.
</div></li><li data-sub-note-item="3-5"><div class="lab-step">When the alarm sounds, stop the timer, and count the number of flies in the open side B of the chamber.
</div></li><li data-sub-note-item="3-6"><div class="lab-step">Subtract that number from the total number of flies added to the choice chamber to calculate the number of flies in the covered side A.
</div></li><li data-sub-note-item="3-7"><div class="lab-step">Record these data in the table for time point 10.  <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/15/Table_2_Animal_behavior.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Table 2</a>
</div></li><li data-sub-note-item="3-8"><div class="lab-step">Carefully, return all of the flies back to their empty vial.
</div></li></ul></li><li data-note-item="4" data-parent-collapse="">Chemotaxis
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="4-1"><div class="lab-step">HYPOTHESES: In this exercise, the alternative hypothesis is that more flies will be found on the side of the chamber with the apple cider vinegar if the flies are attracted to the odor. Or, if the flies are repelled by the vinegar, then more of them will be found on the side of the chamber presenting the odorless water. The null hypothesis is that <em>Drosophila</em> will have no preference with regard to either stimulus and will move randomly in the chamber.  Use an individual disposable plastic pipette to dispense two drops of the apple cider vinegar onto one cotton ball for side A of the chamber. 
</div></li><li data-sub-note-item="4-2"><div class="lab-step">Use an individual disposable plastic pipette to dispense two drops of the distilled water onto a cotton ball for side B of the chamber. 
</div></li><li data-sub-note-item="4-3"><div class="lab-step">Fold two pieces of tape over themselves to create individual pieces of double-sided tape and use the tape to attach each cotton ball to the inside of the single bottle cap.
</div></li><li data-sub-note-item="4-4"><div class="lab-step">Screw the bottle caps with the cotton balls onto their corresponding sides of the chamber.
</div></li><li data-sub-note-item="4-5"><div class="lab-step">Transfer all of the flies into the chamber and set the timer to sound an alarm after 10 minutes. 
</div></li><li data-sub-note-item="4-6"><div class="lab-step">When the alarm sounds, stop the timer and record the number of flies in each side of the chamber. <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/15/Table_3_Animal_behavior.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Table 3</a>
</div></li><li data-sub-note-item="4-7"><div class="lab-step">At the end of the final experiment, funnel the flies into a morgue tube containing 70% ethanol. 
</div></li><li data-sub-note-item="4-8"><div class="lab-step">Dismantle the choice chambers for recycling.  NOTE: Since all of the chemicals used in these experiments are lab safe, the liquids can be disposed of down the sink, the chambers rinsed, and the solids can be thrown away in the trash. 
</div></li></ul></li><li data-note-item="5" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="5-1"><div class="lab-step">Gather all of the data collected for the geotaxis, phototaxis, and chemotaxis experiments.
</div></li><li data-sub-note-item="5-2"><div class="lab-step">Plot these values as bar graphs for different conditions and different time points.
</div></li><li data-sub-note-item="5-3"><div class="lab-step">Use these data to draw inferences about the behavior of <em>drosophila melanogaster</em>. 
</div></li></ul></li></ol>

Animal Behavior: Studying Taxis Behavior of Drosophila - Procedure

Comportement animal

Making Choice Chambers
ExpandBefore beginning the experiments, use one of the Sharpies from the lab table to trace a line around the circumference of the ...

Artificial Selection

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Observing Artificial Selection in Plants 
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">To begin the experiment, collect five two-week old grown plants from the generation one population that appear healthy. Note: Plants should appear green, not wilted, and not have damaged leaves. Experimental Hypothesis: The experimental hypothesis for this lab might be that the number of lead trichomes varies naturally, but the average number will increase over generations if only plants with the highest number of trichomes are interbred or decrease if those with the least are interbred. Null Hypothesis: The null hypothesis might be that the average number of trichomes will not change over subsequent generations after artificial selection.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Label each plant with a letter from A to E and with both partners&#8217; names.
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Record any natural differences you see between your plant samples. Note: All of the plants are the same age, so any observed variation is due to expressed phenotype, not development.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Use a hand lens to count the number of trichomes found on the petiole of the lowest leaf, not including the round, first-grown cotyledons for each plant. Note: It can be helpful to shine a light onto the plant and to hold it against a dark background, such as a lab bench, during the trichome analysis. 
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Both partners will conduct counts on each plant independently and compare answers. If the counts are different, enlist a third counter or take the average of the two results.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">After this, determine the median number of trichomes for the entire class.  <a target="__blank" style="display:block;padding:20px;" href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/2/Lab_2_Table_A.xlsx">Click Here to download Table A</a>
</div></li><li data-sub-note-item="1-7"><div class="lab-step">Determine the top and bottom 10% of the plants from the class trichome count. These groups will make up the two artificially selected lines: high hairiness and low hairiness, respectively.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">If more than 10% of the plants have no trichomes, select 10% of those plants randomly for the low hairiness plant line.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">Separate the two groups of selected plants and label them clearly.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">Move the plants to a well-lit area and keep them well watered until they develop flowers. Note: Flowers typically develop around 14 days.
</div></li><li data-sub-note-item="1-11"><div class="lab-step">When the flowers are fully developed, use a pollination wand or paintbrush to rub the stigma and anther of one plant&#8217;s flowers for a few seconds.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">Using the same wand or brush, rub the inside of each flower of every other plant in the same selection line.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">Using a different wand or brush, repeat steps 11 through 12 on the other line. Note: Take care not to cross the lines. Spread the pollen only among the appropriately selected plants.
</div></li><li data-sub-note-item="1-14"><div class="lab-step">Return the generation one plants to the growing areas. When the plants reach approximately 1 month old, they should produce mature seed pods.
</div></li><li data-sub-note-item="1-15"><div class="lab-step">Allow the plants to dry out once the seed pods turn yellow.
</div></li><li data-sub-note-item="1-16"><div class="lab-step">Break the seed pods open and collect the seeds.
</div></li><li data-sub-note-item="1-17"><div class="lab-step">Obtain new pots for the generation two seeds.
</div></li><li data-sub-note-item="1-18"><div class="lab-step">Fill the pots with moist potting soil about halfway and add a fertilizer pellet to each pot.
</div></li><li data-sub-note-item="1-19"><div class="lab-step">Fill the pots with more soil to fill just below the lip.
</div></li><li data-sub-note-item="1-20"><div class="lab-step">Make a shallow depression in the soil of each pot with a probe.
</div></li><li data-sub-note-item="1-21"><div class="lab-step">Touch a clean toothpick to a gluestick and use the toothpick to transplant the seeds into the soil one by one.
</div></li><li data-sub-note-item="1-22"><div class="lab-step">Cover the seeds with a thin layer of soil.
</div></li><li data-sub-note-item="1-23"><div class="lab-step">Label the pots with their hairiness line and place them in the designated growing area.
</div></li><li data-sub-note-item="1-24"><div class="lab-step">Use a plastic dropper to water the plants as needed to ensure they do not dry out.
</div></li><li data-sub-note-item="1-25"><div class="lab-step">When the plants are two weeks old, collect five plants from each line and label them A to E.
</div></li><li data-sub-note-item="1-26"><div class="lab-step">Then, count the trichomes on these plants as previously described (steps 4- 5).
<a target="__blank" style="display:block;padding:20px;" href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/2/Lab_2_Table_B.xlsx">Click Here to download Table B</a>
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Data Analysis
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">Create a frequency graph based on the generation one class data with the trichome count on the x axis and the number of plants on the y axis. Label the mean. 
</div></li><li data-sub-note-item="2-2"><div class="lab-step">Then, create frequency graphs for both of the selected hairiness lines.
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Compare the frequency graphs for generation one and both hairiness lines.
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Take note of phenotypic shifts observed in the selected hairiness lines.
</div></li></ul></li></ol>

Artificial Selection: Visualization in Plants and Data Analysis - Procedure

Sélection artificielle

Observing Artificial Selection in Plants 
ExpandTo begin the experiment, collect five two-week old grown plants from the generation one population that ...

Natural Selection

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Simulating Natural Selection
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">To begin, cut the white, black, and gray pipe cleaners into quarters, which should produce a total of 100 pieces that are 3 inches long.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Then, cut the green pipe cleaners in the quantities and lengths specified in the video, taking care to minimize waste. This approximates a normal distribution of lengths and should result in an additional 100 pieces total. NOTE: One 12-inch pipe cleaner should yield multiple lengths, for example, a 5-inch piece and a 7-inch piece. Use this advantage to reduce waste.
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Now, cut one sheet of black and one sheet of white construction paper into approximately 3-inch strips measured along the long edge of the paper.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Tape these strips down to cover the base of a dissecting tray to create an alternating pattern of black and white strips. NOTE: In the first simulation, you will use the white, gray, and black pipe cleaner segments against a black and white background to simulate different selection pressures due to predation on a population. You will select your prey using two different strategies, eyes-open and eyes-closed. For each of these strategies, you will perform four rounds consisting of 25 selections, alternating between two partners. After each round you will restore the population back to its original size using the proportions of phenotypes present after selection.
</div></li><li data-sub-note-item="1-5"><div class="lab-step">To begin the first scenario, count out 12 white, 12 black, and 26 gray pipe cleaner segments with your partner. Hypotheses: Here the experimental hypothesis might be that different predation strategies, such as having the eyes open or closed, will result in distinct selection pressures on the populations. Further, different phenotypes may be positively selected in the alternate scenarios. The null hypothesis might be that different predation strategies will have no effect on the populations or phenotypes.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">Mix the pipe cleaner segments together as best as possible. Then, sprinkle them into the papered tray. NOTE: Ideally, the pipe cleaners will be spread out. However, this may not occur due to their self-adhering nature.
</div></li><li data-sub-note-item="1-7"><div class="lab-step">Once the segments are in the tray, separate them as best as possible without moving them too far from where they landed. As few segments as possible should be touching.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">Have the first partner close their eyes. When given an audible signal by the second partner, the first should open their eyes and grab the first pipe cleaner they see from the tray as quickly as possible.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">Set the removed pipe cleaner to the side.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">Alternating partners, repeat this process a total of 25 times (steps 8 &#8211; 9).
</div></li><li data-sub-note-item="1-11"><div class="lab-step">Count the remaining pipe cleaners by color and record this in the data collection table for Scenario 1. <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/23/Lab_23_Tables_1_and_2.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Tables 1 and 2</a>
</div></li><li data-sub-note-item="1-12"><div class="lab-step">Then, restore the population to 50 by adding one pipe cleaner of the same color for each of the remaining pipe cleaners. Hold these to the side until they are all gathered.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">Then, sprinkle the pipe cleaners into the tray as previously described (steps 6-7). Repeat this process for three more rounds consisting of 25 selections each and record the counts for each of the rounds in the data collection table for Scenario 1.
</div></li><li data-sub-note-item="1-14"><div class="lab-step">Remove all pipe cleaners from the tray after the fourth round.
</div></li><li data-sub-note-item="1-15"><div class="lab-step">For Scenario 2, again count out 12 white, 12 black, and 26 gray pipe cleaner segments and sprinkle them randomly into the tray.
</div></li><li data-sub-note-item="1-16"><div class="lab-step">Follow the same protocol as in Scenario 1. However, when given the signal, the grabbing partner should keep their eyes closed. To aid in accuracy, it may help to position the hand near to the tray before grabbing.
</div></li><li data-sub-note-item="1-17"><div class="lab-step">Repeat this process 25 times, switching partner roles, and record the remaining pipe cleaner amounts in the data collection table for Scenario 2.
</div></li><li data-sub-note-item="1-18"><div class="lab-step">Then, restore the population to 50 based on that count. Do this for all four rounds. NOTE: In the second simulation, you will be using the eyes-open and eyes-closed predation strategies as previously described to select pipe cleaners of various lengths.
</div></li><li data-sub-note-item="1-19"><div class="lab-step">For Scenario 3, gather all 100 of the pipe cleaners that have been cut to varying lengths to represent different phenotypes.
</div></li><li data-sub-note-item="1-20"><div class="lab-step">One partner should hold all the pipe cleaners upright and loosely in one hand resting on the tabletop, such that the bottom end of each pipe cleaner rests against the tabletop.
</div></li><li data-sub-note-item="1-21"><div class="lab-step">Now, the partner that is not holding the pipe cleaners should close their eyes. When given an audible signal, the partner should open their eyes and grab the first pipe cleaner they see from their partner&#39;s hand.
</div></li><li data-sub-note-item="1-22"><div class="lab-step">Repeat this process 50 times (step 21). However, the partners should not switch roles during the round this time. The partner holding the pipe cleaners should always be the one giving the signal and never grabbing from the bunch.
</div></li><li data-sub-note-item="1-23"><div class="lab-step">After the first round consisting of 50 selections, count the remaining pipe cleaners by length. Then, record this information in the data collection table for scenario three. <a href="https://www-jove-com.bdigitaluss.remotexs.co/CDNSource/lm/labs/23/Lab_23_Tables_3_and_4.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Tables 3 and 4</a>
</div></li><li data-sub-note-item="1-24"><div class="lab-step">Add one pipe cleaner of the same length as each of the remaining ones to restore the population to 100. This will likely require more pipe cleaners than were originally cut. Try to use scraps from the class to reduce waste.
</div></li><li data-sub-note-item="1-25"><div class="lab-step">Repeat this for three more rounds, alternating which partner holds or grabs each round.
</div></li><li data-sub-note-item="1-26"><div class="lab-step">To perform Scenario 4, gather the varied-length pipe cleaners in their original proportions.
</div></li><li data-sub-note-item="1-27"><div class="lab-step">Now repeat the grabbing process, as described in Scenario 3. However, only remove 30 pipe cleaners instead of 50.
</div></li><li data-sub-note-item="1-28"><div class="lab-step">Divide the count at the end of each round by two for each phenotype 4 inches or below, rounding fractions down.
</div></li><li data-sub-note-item="1-29"><div class="lab-step">Then, record these values in the data recording table for Scenario 4.
</div></li><li data-sub-note-item="1-30"><div class="lab-step">Use the relative proportions of the phenotypes in the final population to restore the population to 100. When restoring the population to 100, it may be necessary to calculate relative proportions of phenotypes.
</div></li><li data-sub-note-item="1-31"><div class="lab-step">Repeat this for three more rounds, again alternating holding and grabbing the pipe cleaners.
</div></li><li data-sub-note-item="1-32"><div class="lab-step">For each scenario calculate the survival for each phenotype, that is the proportion of the phenotype surviving.
</div></li><li data-sub-note-item="1-33"><div class="lab-step">Then, calculate the relative fitness, or w, between each round. As reproductive rate does not vary in this simulation, this should always be considered equal, or 1.
</div></li><li data-sub-note-item="1-34"><div class="lab-step">Also, calculate the selection coefficients for each phenotype.
</div></li><li data-sub-note-item="1-35"><div class="lab-step">Now, use the relative frequencies of each phenotype to create histograms with appropriately labeled axes for each scenario showing the population before any selection took place and then alongside these in a different color after four rounds of selection.
</div></li><li data-sub-note-item="1-36"><div class="lab-step">Identify the type of selection taking place in each scenario and label the graphs. 
</div></li><li data-sub-note-item="1-37"><div class="lab-step">Develop a hypothesis to explain your observations. 
</div></li></ul></li></ol>

Natural Selection: Calculating Fitness and Selection - Procedure

Sélection naturelle

Simulating Natural Selection
ExpandTo begin, cut the white, black, and gray pipe cleaners into quarters, which should produce a total of 100 pieces that ...