Evolution Review Answers
1. Darwin was the individual that came up with the idea of evolution.
Scientists that came before Darwin had studied fossils they found in different layers of sedimentary rock and seen the natural progression of animal species from fish to amphibian to reptile and finally mammals. It was these scientists that first came up with the idea of evolution. In fact, others had come up with their own theories about how evolution occurred (e.g. Lamarck). Darwin was not the first to come up with the idea of evolution, he was, however, the first to propose a mechanism that explained how evolution worked: natural selection.
2. Organisms are somehow directing their own evolution.
This is Lamarcks idea and it is wrong. For example, a giraffe cannot reach for leaves all its life, make its neck longer, and have this communicated to its offspring. There is no evolution of acquired characteristics.
3. Evolution is moving toward a goal.
Evolution is not moving toward a goal. Species are evolving by simply being the best survivors in their particular environment at a particular time in history. For example, degenerative evolution can occur in which cave fish lose their eyes since they do not need them while other fish have excellent eyesight since they need eyes for survival. One cannot say that fish evolve with a particular goal of eyes or no eyes- it simply depends on the current environmental pressures put on a population of organisms at a particular time.
4. Species normally evolve smoothly and directly into new species.
No. Look at the evolution of the horse, page 461 in the book, there are many dead ends! Also, the discontinuous fossil record shows that evolution is not smooth- the evolution of life looks more like Punctuated Equilibrium.
5. The fossil record gives a complete picture of evolution.
No, there are many gaps in the fossil record.
6. The best evidence that evolution is true are the marvelous adaptations that have arisen through time.
Not really- this could actually be evidence of a creator. The better evidence for evolution is when we find adaptations that arent perfectly adapted like the pandas thumb which do the job that fits the environment they are in using whatever anatomical structures they had to begin with.
7. Evolution can only be said to occur when you get a new species forming.
No, since the Modern Synthesis (Darwinian evolution + population genetics) a simple change in allele frequency in a population is considered evolution. Specifically it is called microevolution. The process in which new species are formed is called macroevolution.
8. Natural Selection is the only process that can cause evolution.
No. It is far and away the main process that causes evolutionary change but not the only process. The Hardy-Weinberg Equilibrium identifies four other things that can cause evolution.