PSYO 2160 Lecture Notes - Lecture 10: Camoflauge, E. O. Wilson, Eastern Gray Squirrel
9 May 2018
School
Department
Course
Professor
Natural Selection
Sub Types of Fitness
o Not necessarily survival of the fittest, this point wasn't actually created by Darwin
o Darwinian fitness has to do with the immediate effect on fitness
o
Indirect fitness is what biology focuses on today -
based on things that may emerge from altruism or
symbiosis q
c
(interspecies
relations)
3 Types of Direct Fitness
o Ex. Good camoflauge
o Correlated traits
o Pleiotropy - traits that happen to be associated with a gene, but natural selection alters
it
o Argue that black squirrels in the urban environment have an advantage - has
nothing to do with the fact that they are black, but that they are more aggressive
and can compete with grey squirrels
o Sexual selection
o What various species look for in their mates - paradox
o Handicap principle - The fact that if an individual is able to survive with a
handicap, they are that much more sexually appreciated because they are able to
survive with it.
o Ex. Peacock tail - they can't fly, so if they are still alive regardless of their
handicap, they are that much more sexually appreciated
Phenotype and Evolution
o Expression of the genes is what matters
o Sociobiologist commonly measure the behaviour in regards to reproductive success
o Outcomes of reproduction (how many eggs, how many are born, how many will be
able to reproduce, etc.)
o Need individuals that will become sexually active
o Ex. Not all humans reproduce, Eusocial species, naked mole rats (individuals in the
group that are just not meant to reproduce)
o Even the individuals who don't reproduce, will still play a role or help in
reproduction to increase the reproductive success of their species (kin selection)
o What is fit right now, may not be fit in a month - you are born fit within certain constraints
o Dependent on the environment - ex. Global warming and polar bears
Cooperation and Competition
o There are individuals that have a massive impact, and the group will not survive without
them, however the pack would not survive without them
o Altruistic behaviour - cost to the actor but benefit to the recipient
o Where an individual will sacrifice themselves for the betterment of another individual
o Selfish behaviour - where there is a benefit to the actor but a cost to the recipient
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Document Summary
Sub types of fitness: not necessarily survival of the fittest, this point wasn"t actually created by darwin, darwinian fitness has to do with the immediate effect on fitness. Indirect fitness is what biology focuses on today - based on things that may emerge from altruism or symbiosis q c (interspecies relations) Peacock tail - they can"t fly, so if they are still alive regardless of their handicap, they are that much more sexually appreciated. Racoons: spiteful behaviour - cost to both the recipients and the actors, where they are so pissed off that they will put both themselves and their opponent in danger, very counter productive. Symbiosis: mutualism - where two species interact and they both benefit, ex. Clownfish and anemone, clownfish benefit by the protection of the anemone while the anenome gets food off of the clownfish: commensalism - where one species benefits and the other one neither benefits nor is harmed, ex.
