Terms to know: the molecular clock hypothesis, heterosis, local adaptation, heritability,  altruism,  kin selection, sexual selection.

Questions:

1. What living species are most closely related to humans?  What DNA data were used to study the relationships between humans and their very closest relatives?  Why was this region of DNA used rather than one of the other DNA regions? What is a potential problem with using this region?
2. Give an example of a human characteristic for which ontogeny recapitulates phylogeny? Give an example of a human characteristic for which ontogeny does not recapitulate phylogeny.  Which of these has evolved through paedomorphosis?  Which through terminal addition?  Which follow von Baer's Law?  Give the phylogenetic evidence that supports your answers.
3. The phylogeny obtained using the molecular clock for human populations looks something like the tree below.  Explain what this phylogeny, if it is correct, indicates about the geographic origin of humans.
4. Explain how the date of the ancestor to modern humans in the tree shown above was determined.  What kinds of information were needed?  Upon what assumption is this method based?
5. The fossil record and the molecular clock hypothesis based phylogeny shown above differ with regard to the time when the ancestor to modern humans dispersed from Africa.  How do they differ?  Give possible explanations for the discrepancy.
6. How have different molecular techniques been used to distinguish between the African Replacement Model and the Multiregional Model of human origin?  How does the possibility of gene flow make it difficult to clearly distinguish between these models?
7. What is the most common way in which single-gene human genetic diseases are coded (i.e. are they dominant? recessive? codominant?).  Give an evolutionary explanation for this.
8.  Sickle-cell anemia and cystic fibrosis are genetic diseases that are much more common than are most human genetic diseases.  Give an evolutionary explanation for the relatively high frequency of these diseases compared to other genetic diseases.
9.  Use skin pigmentation in humans to illustrate the concept of local adaptation.
10. What does allozyme information indicate about the relative importance of gene flow versus genetic drift in humans in general?  Based on this information, do you expect a large amount of local adaptation?
11. Why is it difficult to determine the heritability of human behavioral traits such as IQ?  What methods are used to determine heritability in other species, and why are these problematic in humans?  Are these methods expected to overestimate or underestimate the heritability of human behavioral acts?  What methods HAVE been used to estimate heritability of human behaviors? What is the basis for these methods (why should they provide estimates of heritability)?  Why are these methods problematic?  When we start discussing heritability of traits such as IQ, we get into is an area in which it is hard to be objective -- do you think you are evaluating this information in a way that is as unbiased as you would if you were considering a study of some other species and some other trait?
12. What is sociobiology?  What is human sociobiology?  Upon what assumptions does human sociobiology depend?  Give examples of sociobiological explanations for specific behavioral acts in humans.  Do you think these are reasonable?
13. In a cross-cultural study of many human societies, the following pattern was observed.  Human societies generally have some form of marriage, but there is a fair amount of variation in sexual fidelity. In some societies, there are high levels of sexual intercourse outside marriage.  In such societies, men generally leave their possessions to the children of their sisters, not to the children of their own marriage.  In other societies, there are low levels of sexual intercourse outside marriage.  In such societies, men leave their possessions to the children of their marriage.  Give an explanation of this situation based on kin selection.   Can you think of another hypothesis that could explain this behavior?
14. Describe the study of human mate choice based on odor.  What other aspect of a male was apparently indicated by his odor (other than how he smelled?)  With which hypothesis of sexual selection is this study most consistent?  Explain why.
15. Compare human behavior to the behavior of related species.  What similarities are there between humans and their close relatives?  What differences are there? If humans and their close relatives share particular behavioral traits, does this mean that these behavioral acts are the natural and appropriate behavioral acts of humans? Why/ why not?