BIOL 2060 Lecture Notes - Lecture 5: Ground Squirrel, Kin Selection, Inclusive Fitness
3 May 2018
School
Department
Course
Professor
Behaviour & Life History
January 15th, 2016
Chapter 8-9
Organisms exhibit a diversity of behaviours.
Behavioural Ecology
Study of Social Relations
• Interactions between organisms and the environment are often mediated by behaviour
o Dominance relationships
o Reproductive relationships
o Cooperation
• Interaction can be between individuals, between groups or within groups
• Behavioural Interactions:
o Donor & Recipient
o ++ cooperation
o +- selfishness
o -- spite
o -+ altrusism
Why do organisms behave?
• Evolution
o Natural selection acts on individuals
o Behaviour can affect fitness
• Behaviour can be a characteristic upon which natural selection acts
Individual Behaviour: Risk Taking
• (1) Value of Reward
• (2) Hunger Level
• (3) Probability of predation
• The threshold for risk taking may depend on local conditions
Group Behaviour:
• Inclusive fitness = an individual’s overall fitness is determined by its own survival and
reproduction PLUS the survival and reproduction of all relatives
o Kin selection – helping relatives(selfish)
o Altruism – individuals may act counter to their own personal interest for the
betterment of the group
• Ex. Belding’s ground squirrel
o Alarm calls increase likelihood of being attacked, but also ability for others to
escape
o Alarm calls more likely when relatives are nearby and are more closely related
o Ability to recognize kin or litter mates is essential
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Document Summary
Interactions between organisms and the environment are often mediated by behaviour: dominance relationships, reproductive relationships, cooperation, behavioural interactions: Interaction can be between individuals, between groups or within groups: donor & recipient, ++ cooperation, +- selfishness, -- spite, -+ altrusism. Why do organisms behave: evolution, natural selection acts on individuals, behaviour can affect fitness, behaviour can be a characteristic upon which natural selection acts. Individual behaviour: risk taking (1) value of reward (2) hunger level (3) probability of predation: the threshold for risk taking may depend on local conditions. Sociality: living in a group fundamentally changes the relationship among individuals, evolution of sociality accompanied by, cooperative feeding, defense of the social group, restricted reproductive opportunities, cooperation generally involved the exchange of resources and other forms of assistance. Iridescent area: total pigmented area, orange area. Trade-offs: sexual costs & conflicts: costs: disease risk, time, energy, vulnerability, conflicts will arise if costs are unequally shared between sexes, ex.
