Steven Crane Compiled Section Handouts. Human Behavioral Biology 2012

Kidnapping by male baboons (and not kidnapping when high-ranking male just joined the troupe)

Relatedness in dominance hierarchies. Females inherit their rank

Sex ratios.

1. 
   Males are more "expensive" but high ranking tournament species females will gamble on a son instead of a daughter. What's the proximate mechanism here? Higher-ranking females have better nutrition so sons will be more likely to be carried to term.
   
2. 
   Sex ratios will stabilize over time near 50-50.
   

Paying attention to alarm calls as a function of relatedness

Male-male cooperation

Instances of polyandry (multiple males leading a harem). Usually adelphic (by related males). Includes humans (see traditional Tibetan marriage patterns).

Why would you mate with relatives?

1. 
   Share more genes with them so more of your genes make it into the next generation. Great!
   
2. 
   But if they're too closely related than recessive disease-causing alleles are likely to be inherited and cause disease. Not so great!
   
3. 
   Where does the "optimal" mating occur, according to the Helgason "Kinship and Fertility" reading? 3rd
   

or 4th cousin matings produce the most fertile offspring.

8. 
   How do chimps vs. baboons differ in which gender leaves the troupe? What consequences does that have?
   
   1. 
      Baboons: males leave the troupe. Females stay and are more related.
      
      1. 
         Males kill each other more
         
   2. 
      Chimps: females leave the troupe. Males stay and are more related.
      
      1. 
         Males band together and often kill neighboring males. This is protowarfare and genocide.
         

Group selection. Is it valid? What version is invalid?

1. 
   Not for the good of the species.
   
2. 
   Yes multi-level selection.
   
   1.