Behavior Chapter 51 U106PP

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Behavior- Chapter 51 U106PP
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Social behavior (sociobiology)

• Does it improve fitness?
• Pros
• Protection
• Shared information (resources)
• Cooperation
• Cons
• Spread of disease
• Easier for predators to locate
• Potential for conflict

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• Concept 51.6 The concept of inclusive fitness
  can account for most altruistic social behavior
• Many social behaviors are selfish (maximizing own
  survival and reproduction)
• Natural selection favors behavior
• That maximizes an individuals survival and
  reproduction

Conflict? How can you live in a population with
GROUP behavior norms and still maximize your OWN
fitness?
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Altruism

• On occasion, some animals
• Behave in ways that reduce their individual
  fitness but increase the fitness of others
• This kind of behavior
• Is called altruism, or selflessness

Apparent altruism in non-mating birds?
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• In naked mole rat populations
• Nonreproductive individuals may sacrifice their
  lives protecting the reproductive individuals
  from predators

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Inclusive Fitness

• (apparent) Altruistic behavior can be explained
  by inclusive fitness
• The total effect an individual has on
  proliferating its genes by producing its own
  offspring and by providing aid that enables close
  relatives to produce offspring

AHHH! By helping relative, you help your OWN
genes!!!!
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Hamiltons Rule and Kin Selection

• Hamilton proposed a quantitative measure
• For predicting when natural selection would favor
  altruistic acts among related individuals

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• The three key variables in an altruistic act are
• The cost to the altruist
• The benefit to the recipient
• The coefficient of relatedness

If r B gt C
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• The coefficient of relatedness
• Is the probability that two relatives may share
  the same genes

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• Natural selection favors altruism when the
  benefit to the recipient
• Multiplied by the coefficient of relatedness
  exceeds the cost to the altruist
• This inequality
• Is called Hamiltons rule

I would gladly give my life for two brothers or
8 first cousins - Haldane
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• This particular notion (of favoring relatives
  over strangers) is called Kin selection
• favors this kind of altruistic behavior by
  enhancing reproductive success of relatives

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• An example of kin selection and altruism
• Is the warning behavior observed in Beldings
  ground squirrels

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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

Potential to cheat?
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Social Learning

• Social learning
• Forms the roots of culture
• Culture can be defined as a system of information
  transfer through observation or teaching
• That influences the behavior of individuals in a
  population

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Mate Choice Copying

• Mate choice copying
• Is a behavior in which individuals in a
  population copy the mate choice of others

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• This type of behavior
• Has been extensively studied in the guppy
  Poecilia reticulata

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Social Learning of Alarm Calls

• Vervet monkeys
• Produce a complex set of alarm calls

• Infant monkeys give undiscriminating alarm calls
  at first
• But learn to fine-tune them by the time they are
  adults

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• No other species
• Comes close to matching the social learning and
  cultural transmission that occurs among humans

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• Human behavior, like that of other species
• Is the result of interactions between genes and
  environment
• However, our social and cultural institutions
• May provide the only feature in which there is no
  continuum between humans and other animals