Biol 3350 1st Edition Lecture 18 Outline of Last Lecture I. Sperm competition as a function of mating system: nonhuman primatesII. Male-Male Competition in HumansIII. Bateman’s PrinciplesIV. Alternative Male StrategiesV. Male Reproductive Tactics: InfanticideVI. Female Counterstrategies to InfanticideVII. Parental – Investment TheoryVIII. Sexual Selection and Mate ChoiceIX. Sexual Displays can be costlyX. How does the good-genes model work?Outline of Current Lecture I. Social interactions create the opportunity for both conflict and cooperationII. Adaptive Behaviors vs. Altruistic BehaviorsIII. AltruismIV. Hamilton’s RuleV. Beldings Ground SquirrelsVI. White Fronted Bee EatersVII. MeerkatsCurrent LectureI. Social interactions create the opportunity for both conflict and cooperationa. An individual behaves in ways to increase its own fitness relative to everyone else– natural selection is a competitive processb. When pairs cooperate in 3s, their survivorship is much enhancedc. Most human forms of punishment would fit into “spiteful” – tribal societies go oncattle raids, but not everyone wants to participate because people died. Societal level punishment – humiliate people who do not go on the raids; take energy and time from the actorsII. Adaptive Behaviors vs. Altruistic Behaviorsa. Adaptive:i. Cooperative and selfishii. Increase own fitnessiii. Favored by natural selectionb. Altruistic:These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. Altruistic and spitefulii. Decreases own fitnessIII. Altruisma. Can evolve if:i. The species benefits from the behavior of the altruistii. A relative of the altruist benefits from the behavior of the altruistb. Natural selection – the individual does a behavior that is compared to the rest of the groupc. If more relatives benefit from the behavior of the altruist, the altruistic genes canbe passed onto the next generationsIV. Hamilton’s Rulea. Alleles for altruistic behaviors will spread if: Br-C>0i. B = benefit to the recipientii. r= coefficient of relatedness1. r for relatives:a. Parent-offspring = 0.5b. Full siblings = 0.5c. Grandparent-grandchild = 0.25d. Half siblings = 0.25e. Uncle-nephew = 0.25f. Cousins = 0.125iii. C = cost of the actorb. Inclusive fitness is more than just one’s own fitnessV. Beldings Ground Squirrelsa. Whistling callers are attacked 2% time compared to 20% when you don’t call à whistling is not atruistic behaviorb. Trilling ground squirrels are attacked 8% of the time and non-trilling are attacked 4% of the time à trill increases chance of dyingc. If it is adaptive, relatives will benefitd. The more closely related to someone, the more likely it is that you will call when you see then out in an open, vulnerable positionVI. White Fronted Bee Eatersa. The nests had many adults incubating them and bringing food to them, not just the immediate father and motherb. Most nests have “helpers” which do not produce own offspring, but contribute to the reproductive success of other individualsc. Individuals who are widowed or who’s nests have failed end up being the helpersd. Young males help more frequently than females à Cooperative breadinge. With more helpers à better chance of offspring survival because receiving more foodf. Almost a linear relationshipg. 0.5 and 0.25 relatedness are more likely to help than by chance aloneh. Those who are distantly related or not related at all are less likely to help than close relativesVII. Meerkatsa. Meerkats are cooperatively breeding mammals as wellb. Usually only one female breeds, but all of the other members of the group helps to take care of that child by feeding it and protecting it from predatorsc. Closely related relatives help more than distantly related