 |  Biology, 6/e Author Dr. George B. Johnson,
Washington University
Author Dr. Peter H. Raven,
Missouri Botanical Gardens & Washington University
Contributor Dr. Susan Singer,
Carleton College
Contributor Dr. Jonathan Losos,
Washington University
How Humans Evolved
Answers to Review Questions| Chapter 23 (p. 492)
1. The first primates were the prosimians. The significant contribution to their selective success was their improved ability to live in trees and capture insects.
2. Monkeys are diurnal and possess both color vision and an opposable thumb. These adaptations make them more competitive and successful in nature.
3. Almost all apes are larger than monkeys, possess large brain cavities, and have no tails.
4. Human and chimpanzee nucleotide sequence is so similar because the evolutionary divergence between chimpanzees and humans was so recent.
5. The earliest hominids were called Australopithecines, and appeared fifteen million years ago. They were distinguished from the apes by a larger brain case and upright (bipedal) gait.
6. The group was short-lived and very similar to the Australopithecines.
7. H. erectus was taller, walked upright, had a large braincase, prominent brow ridges, and a rounded jaw.
8. It tells us that Africans are the oldest humans, and that Africa is almost definitely the continent where Homo evolved prior to its migration all over the globe.
9. Cro-Magnons looked more "human-like" and used sophisticated tools out of stone, bone, and horns. They clearly had a complex social organization, probably complete with a well-developed language. They hunted and gathered in cooperative groups, and left the paintings on cave walls that are so spectacular to us now. Fossil evidence shows that Cro-Magnons and Neanderthals existed at the same time, at least in Europe. By 40,000 years ago, the Neanderthals had been completely replaced by the Cro-Magnons.
10. The distinctions by which we determine races are inadequate and improper to distinguish them as subspecies. |
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2002 McGraw-Hill Higher Education