WZ lect9 Sept 21

WZ lect9 Sept 21 - Biological Sciences 120 Lecture 9, Sept....

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 51, 55.1-2 Biological Sciences 120 Lecture 9, Sept. 21 Wiebke Ziebis Behavioral and Social Evolution cont. Conservation genetics  Ecosystems
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
What you need to know from the previous lecture: Lecture 8: Behavioral and Social Evolution, Ch. 51  Behavior - phenotype - response to external and internal stimuli Ethology - study of behavior Proximate and ultimate causation - behavioral ecology Kinesis and taxis Migration Communication Innate behavior - learning (habituation,imprinting,spatial learning,associative learning, classical conditioning, operant conditioning, cognition, problem solving) Development of learned behaviors Animal behavior is governed by complex interactions between genetic and environmental factors
Background image of page 2
Inclusive Fitness Altruism can be explained by inclusive fitness Inclusive fitness is the total effect an individual  has on proliferating its genes by producing offspring  and helping close relatives produce offspring
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Hamilton’s Rule and Kin Selection William Hamilton proposed a quantitative measure  for predicting when natural selection would favor  altruistic acts among related individuals Three key variables in an altruistic act: Benefit to the recipient (B) Cost to the altruist (C) Coefficient of relatedness (the fraction of genes that, on  average, are shared; r)
Background image of page 4
Fig. 51-28 Parent A Parent B × OR Sibling 1 Sibling 2 1 / 2 (0.5) probability 1 / 2 (0.5) probability
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Natural selection favors altruism when:                       rB > C This inequality is called  Hamilton’s rule Kin selection is the natural selection that favors  this kind of altruistic behavior by enhancing  reproductive success of relatives
Background image of page 6
An example of kin selection and altruism is the  warning behavior in Belding’s ground squirrels In a group, most of the females are closely related to  each other Most alarm calls are given by females who are likely  aiding close relatives
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Fig. 51-29 Male Female Age (months) Mean distance (m) moved from birthplace 300 200 100 0 1 2 3 4 12 13 14 15 25 26
Background image of page 8
Naked mole rats living within a colony are closely related Nonreproductive individuals increase their inclusive fitness  by helping the reproductive queen and kings (their close  relatives) to pass their genes to the next generation
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Reciprocal Altruism Altruistic behavior toward unrelated individuals can be  adaptive if the aided individual returns the favor in the  future This type of altruism is called  reciprocal altruism
Background image of page 10
Reciprocal altruism is limited to species with stable social  groups where individuals meet repeatedly, and cheaters  (who don’t reciprocate) are punished Reciprocal altruism has been used to explain altruism  between unrelated individuals in humans
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

This document was uploaded on 02/14/2011.

Page1 / 89

WZ lect9 Sept 21 - Biological Sciences 120 Lecture 9, Sept....

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online