Evolutionary theory part 2
Download
1 / 14

Evolutionary Theory Part 2 - PowerPoint PPT Presentation


  • 251 Views
  • Updated On :
  • Presentation posted in: Pets / Animals

Evolutionary Theory Part 2. Goals for today. Kin selection and reciprocal altruism How do you assess adaptive value of a behavior? Look at some behavioral examples Introduce some models to explain primate behavior. Kin selection. A form of Natural selection

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

Evolutionary Theory Part 2

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Evolutionary Theory Part 2


Goals for today...

  • Kin selection and reciprocal altruism

  • How do you assess adaptive value of a behavior?

  • Look at some behavioral examples

  • Introduce some models to explain primate behavior


Kin selection

  • A form of Natural selection

  • Individual’s fitness is influenced by fitness of relatives (they share genes!)

Graph Strier pg 123


Altruism-an act that benefits the helper at some cost but helps the receiver.

Selfish-acting on your own self interest to improve your fitness at cost to other’s fitness

Behavioral choices...


How do you predict altruism?

Hamilton’s Rule

Degree of relatedness between actor and receiver

Act’s benefit to receiver’s fitness

Act’s cost to actor’s fitness

c

<

b

x

r


Brother’s helping rear offspring.

R = .5

Benefits to helper’s fitness should be at least twice the cost.

Half brothers helping rear offspring

R = .25

Benefits to helper’s fitness should be at least four times the cost.


Reciprocal Altruism

  • Behavior which is costly to actor but immediately benefits receiver (who is not related)- at some later time, receiver reciprocates.

  • Low dispersal rates

  • Social groups

  • Ability to discriminate between individuals

  • Time frame


Coalitions

Hamadryas baboon

Rhesus monkey


Chimpanzee politics

Yereon- dom. male

Nikkie- dom. male

Luit challenges,

No female support

Yereon and Nikkie

overthrow Luit

Luit and Nikkie form

Coalition, Nikkie gains

Female support

Luit- dom. Male

Nikkie

Yereon

Luit, Nikkie then

overthrow Yereon


Criterion used to evaluate adaptation?

  • Evaluate costs and benefits

  • The compromise between these is the optimal strategy

  • How easily is this done in primatology?


Behavioral Examples...

  • Infanticide


Infanticide

  • Male tenure important factor

  • Female strategies

  • Female counterstrategies


Monogamy (pairbonding)

Males Costs

  • Mate with one female

  • Expend energy

  • defending territory

Males benefits

  • Paternal certainty

  • Exclusive access to

  • resources


Monogamy (pairbonding)

Female Costs

  • Limited mate choice

  • Expend energy

  • defending territory

Females benefits

  • Male care

  • Exclusive access to

  • resources


ad
  • Login