Wk 6 Biology Questions

Chapters 19 and 30

1. Bipedalism has many selective advantages. However, there is one disadvantage to walking on two feet: giving birth to an offspring with a large head through a small pelvic opening, which is necessitated by an upright posture, is very difficult. This situation results in a high percentage of deaths (for mother and child) during birth compared to primates. How do you explain the selection of a trait that is both positive and negative?
2. How might you use biotechnology to show humans today have Neanderthal genes, and therefore, Cro-Magnons and Neanderthals interbred with one another?
3. Some modern ethnic groups (white Europeans and Asians) have apparently inherited genes from Neanderthals that may influence resistance to cold temperatures. What type of genes might this be? Don’t over think this question – think about what physical things help with keeping humans warm
4. Chimpanzees and humans obviously look and act very differently, but their genomes are remarkably similar. What types of mechanisms could explain how small differences in genotype can result in such large differences in phenotype?
5. Because the genomes of chimpanzees and humans are almost identical, and the difference between them are no greater than any two humans, their classification has been changed. Chimpanzees and humans are placed in the same family and subfamily. They are in different “tribes”, which is a rarely used classification category between subfamily and genus. The former classification of chimpanzees and humans placed them in different families. Do you believe that chimpanzees should be classified in the same family and/or subfamily as humans? Or do you prefer the previous classification? Which way seems prejudicial? Give your reasonings.
6. How does genetic analyses of fossils help us understand human evolution better than just examining skulls?
7. Some scientists suggest that the Neanderthals and possibly Denisovans, never went extinct, but instead where assimilated into Homo Sapiens. What evidence would you look for to support this hypothesis?
8. Assuming the Denisovans, Neanderthals, and humans were able to interbreed, what does this tell you about their species status according to the biological species concept?
9. Recent DNA evidence suggests to some plant taxonomists that the traditional way of classifying flowering plants is not correct, and that flowering plants need to be completely reclassified. Other botanists disagree, saying it would be chaotic and unwise to disregard the historical classification groups. Argue for an against keeping traditional classification schemes.
10. What data might make you conclude that the eukaryotes should be in more than one domain? What domain would you hypothesize might be required?
11. If jaguar populations become isolated, would this be enough to classify them as subspecies?
12. Should molecular traits be used to classify human begins?
13. Should one line of evidence hold more weight than another when we discuss the classification of species? Or should all lines of evidence be weighed equally?