Exam 4 Pre Material Flashcards
3 key ingredients needed for natural selection to occur
- Varitaion
- Heredity
- Differential reproduction
Sociality
The tendency of individuals of the same species to live in groups and display reciprocal cooperative behavior
Varying levels of sociality: Presocial
Sociality beyond coutship and mating
Varying levels of sociality: Subsocial
Aggregations: parental care of young for some length of time
Varying levels of sociality: Parasocial
Communal living, but everyone takes care of their own needs/young
Varying levels of sociality: Quasisocial
Community works together to care for young
Varying levels of sociality: Eusocialq
“true” social
Eusociality
Highest level of sociality and extreme altruism
Eusociality- Division of labor with a caste system
sterile worker classes(as) assist reproductive class
Eusociality- Cooperation among…
Group members in rearing offspring
Eusociality- Overlap of generations…
capable of contributing to colony function and living in single group
Social behavior: cooperation
- two or more individuals interact in a way that leads to mutual net benefits from joint actions
- but sometimes free riders cheats
Social behavior: Altruism
Behavior that benefits others at cost of fitness of the altruist
Kinship
individuals who are related behave altruistically to each other
- Natural selection favors traits that pass on genes: related individuals have similar genes
-Individuals = inclusive fitness
Reciprocity
- Individuals benefit by exchanging acts of altruism
- Natural selection favors reciprocal exchange wherein costs are paid back
Group selection
Natural selection acts at the level of the group
Path 1
Kinship
Path 2
Reciprocity
Reciprocal altruism
altruism between unrelated individuals when there will be repaymenet/promise of repayment k
Mobbing Behavior
antipredator tactc; common in birds
Path 3
Group selection
Group selection
Natural selection favors traits that promote survival and reproduction of groups
-kin selection is better
Which organsims are eusocial
Bees, hymenoptera
How has kin selection been used to explain the evolution of eusociality in Hymenoptera?
evolve more frequently in hymenopterans than clades that have diplodiploid sex determination.