Lecture 1: Introduction
•***Not just about surviving, but also reproducing successfully
•Darwin’s theor y of natural selection
1)Variation: organisms’ characteristics VARY WITHIN species
2)Inheritance: some of this variance is PASSED DOWN across generations
3)Selection: individuals with particular heritable characteristics are MORE LIKELY TO
PRODUCE offspring t hat survive
oThen, what/why some characteristics are selected, but not others?
oForms of selection
A)Survival: adaptations that promote the organism’s survival are selected
B)Sexual selection : adaptations that increase access to mates are selected
Intrasexual: adaptations for competition WITHIN sex for mates (huge
pressure because if you are larger more likely to win get female more
Intersexual: adaptations for selection by the other sex
These two sexual selections can be in conf lict with each other (survival vs.
Inclusive f itness theory
•Key to selection isn’t sur vival of offspring per se, but you’re motivated to SHARE the copies
oSurvival of genetic material
oAdaptations that promote success of genetic relatives should be selected
•Would a desire for connection have promoted success in passing on genetic material?
oMust consider the environment of evolutionary adaptiveness
Belonging and survival
•Individuals = vulnerable
•Groups = provide multi-pur pose tools (SURVIVAL + SEXUAL crucial in LIFE OR
oShared food collection and distribution
oAccess to mates
oShared defense against predators and out groups (=SAFETY)
oShared raising of offspr ing (human children are especially vulnerable, and we should help
them survive themselves to have their own children in the future)
•Thus, those who are motivated to belong = MORE LIKELY TO SURVIVE!
The need to belong
•A need for frequent interaction with others in a stable bond MARKED BY AFFECTIVE
CONCERN (emotional caring)