Intro Flashcards
Behavioral Ecology
An ecological and evolutionary approach to the study of behavior
Idealistic view in early 1800’s
Species never change All variation in the species are defects around one ideal form (essentialism) Earth is millions of years old Fossils are only from extinct species New species are created from scratch
Evolution by natural selection requires:
Variation among individuals in
Heritable traits that
Affect the survival or reproduction of the individual
Fitness
Relative number of gene copies contributed by the individual to the next generation (reproductive success [# of offspring] relative to the population average)
Adaptation
The changes or trait that yield higher reproductive success
Animals practicing maladaptive behavior
Hedge sparrow helping cuckoo bird, wood thrush helping cowbird, and the praying mantis
What determines birds’ maladaptive care treatment probability?
Likely the presence or lack there of in time difference between the evolution and presence of the invader and the evolution of the bird species being invaded
Eusocial
An animal species with an advanced level of social organization
Altruism
Self-sacrifice for success of other individuals in group / group
Wynne-Edwards
Group-level selection usually trumps individual-selection behavior
G. C. Williams
Altruism is theoretically possible but not as effective as individual selection, and true altruism is not real
William Hamilton
Helping members in your group indirectly helps fitness
Kin selection
A group of natural selection favoring behaviors that increase the fitness of relatives
Inclusive fitness
Direct fitness + indirect fitness
B and C
B is number of extra offspring from help of individual
C is cost of likely number of offspring from expressed altruistic trait
Pathogenesis for ants, bees, and wasps
Males created from unfertilized eggs
Jacobus Boomsma
Monogamy important for Eusocial creatures in determining effectiveness of this Eusocial altruistic behavior
Phylogeny
Evolutionary tree of species that are derived from a common ancestor
Cooperation
Postponed cooperation
Reciprocity
A & B helping each other now
A eventually gets B’s resources
B helps A back
Maladaptive Altruism
Adaptive Altruism
Spite
Deceit and manipulation
Sacrifices made by A to help B
Sacrifices made initially by A to help A later on
A reduces fitness to harm B
A exploits B in ways that benefit A but harm B
Primary helper
Directly care for relatives rather than go out and find a mate
Secondary helper
Helping at unrelated nest (area) for their fitness
Variables on inclusive fitness
Pg. 7
By-product hypothesis
Ian Jameson; What if genes for maladaptive traits or non-adaptive traits were by-products genes, since they did increase fitness a little bit…
Hamilton’s rule
Helpers are likely those who have a very low ability to reproduce
Parthenogenesis
Females who can asexually reproduce
Adaptionist Approach
You can’t always tell why a behavior comes about, but you can infer some of the benefits
Adaptation
Hereditary trait that spreads throughout a population by natural selection and replaces an alternative trait
Convergent evolution
Similar selective pressures to lead to similar evolution of traits
Divergent evolution
Shared ancestry, divergent behavior
Dilution effect
Safety in numbers for prey
Selfish herd
Even if it would be safer to spread out, their own self interests ask them to stay in the group (kind of still tied to game theory)
Optimality theory
Of 10 (Lec 5)
War of attrition
Outlasting the loser
Dear enemy effect
Once residents know who’s who, fighting occurs less often
Conditional strategy
One not based on genes, but environmental conditions
Runaway selection
Sexual selection for traits which can increase fitness of an individual
Parental sex bias
If one sex or another begins to be more efficient in parenting, then they will be given the task
Trivers-Willard Theory
A sex bias for those who are parented may occur based on possible success of those offspring
Ethology
The classic, natural study of animal behavior
