Lecture 14 - Behavioral Evolution Flashcards
What is behavior?
- what an animal does and how it does it
- includes muscular and nonmuscular activity
What is a proximate question?
- “how” questions about behavior
- focus on environmental stimuli that trigger a behavior
- focus on the genetic/physiological and anatomical mechanisms underlying a behavior act
What are ultimate questions?
- “why” questions about behavior
- address the evolutionary significance of a behavior
What is an example of proximate and ultimate questions?
Schoolling in fish
What is ethology?
- study of behavior, especially under natural conditions
- discipline developed in mid 1900s
What are FAP (Fixed Action Patterns)
- sequence of unlearned behaviors that are largely unchangeable
- usually carried to completion once initiated
- triggered by external stimuli
What is an example of a FAP?
- yawning
- consistent in length and appearance
- difficult to stop once started
What is a FAP in sticklebacks?
the red belly of an intruding male stimulates attack from resident male
What is another fixed action pattern?
goose egg retrieval behavior
What are the axis spectrums for FAPs?
Innate (no modification through learning) - Originates and is modified by learning
Highly stereotyped fixed, (little variation) - Highly flexible (condition dependent)
What is imprinting?
- includes both learned and innate components
- generally irreversible
- develops only during critical period
What is an example of a conditional strategy?
sex change in a clown fish
What is an example of simple learning (conditioning)
Pavlolv’s dog
What is an example of complex learning (cognition)
tool use in chimps
What are 4 characteristics of sexual selection?
- selection for mating success
- may oppose natural selection
- may lead to sexual dimorphism
- involves intra-sexual competition and intersexual choice
Who has larger parental investment?
females (“sperm is cheap”)
What are 2 qualities of female reproduction?
- low success
2. limited by number of pregnancies she can carry
What are 2 qualities of male reproduction?
- success highly variable
2. limited by number of successful matings
What are two examples of sex roles reversing?
in seahorses and pipefish, males carry young in pouch, provide all parental care
What are 2 consequences of reproductive asymmetry?
- sex with low PI should be competitive
2. sex with high PI should be choosy
More mates generally means more ___________
sexual dimorphism
What does polygamous mean?
-type of relationship
in which an individual of one sex mates with
several of the other.
What does polyandrous mean?
-where a female takes two or more husbands at the same time.
What is altruism
-Selflessness
-behavior
that reduces an individual’s fitness while increasing
the fitness of another individual.
What did Darwin believe about altruism?
- presented “special difficult”
- first seemed inscrutable, actually fatal to whole theory
Why do individuals not act “for the good of the species?”
cheater alleles will always win
What might individuals maximize instead of being altruistic?
inclusive fitness
What is inclusive fitness?
the total effect an individual has on proliferating its genes
How does an individual maximize its inclusive fitness?
by enhancing the reproductive success of relatives
What is kin selection?
Natural selection that favors
altruistic behavior by enhancing the reproductive
success of relatives.
What is Hamilton’s Rule
natural selection favors altruism when rB>C
r=relationship coefficient
B=benefit of action
C=cost of action
Applying sociobiology to humans is ______
controversial
What is sociobiology?
The study of social behavior based
on evolutionary theory.
What is MHC?
major histocompatibility complex
Who studied sociology and happened to mention humans in his book?
E.O. Wilson
What was the study on human sociobiology?
- college aged women smelled men’s shirts
- women on BC didn’t have pref
- women on BC did have pref for those with different loci at genes that coded for MHC complex
