Monday, March 29, 2010
Which argument(s) do you find most convincing and/or Which argument(s) raise doubts
Coyne argues the truth behind evolution many different ways: Embryology, Vestiges, Fossils, the influence of different environments on similar creatures (geography of life),etc. Which of Coyne's arguments for evolution do you find most convincing? Which arguments raise doubts? Include in your response textual evidence, as well as, knowledge from outside the classroom.
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I would say that Coyne’s argument about fossils is the most convincing evidence for evolution. When a fossil record is complete, a fossil record provides substantial evidence of evolution by showing previous forms of an organism as well as showing a time line of how an organism evolved.
ReplyDeleteThe ancestors of a present organism show how an organism evolved and became what it is today. With fossils of transitional forms of organisms, people were able to understand how terrestrial predators such as Compsognathus became smaller birds such as chickens (Coyne 41). These fossils backed up evolutionary theories that were not supported by concrete evidence. Modern scientists could now determine how aquatic mammals such as the whale evolved. Campbell provides a very elaborate diagram on page 462 showing how Baleen whales submerged themselves in the ocean.
Another important aspect of fossils is that they provide a timeline of how an organism evolved. Other arguments that Coyne provides, such as vestiges, convergent evolution, or species, only provide evidence that’s gathered from the present. However, by seeing the placement of fossils under rock layers, one could “crosscorrelate the strata from different localities around the world. If a layer of the same type of rock, containing the same type of fossils, appears in two different places, it’s reasonable to assume that the layer is of the same age in both places” (Coyne 23).
An even more modern way to date fossils is by radiocarbon dating. Coyne explains how fossils could be dated by examining the decaying isotopes in fossils (23). Radiocarbon dating is an example of the theme science, technology, and society. With modern technology, we are able to date back fossils and see which millennium an organism lived. By dating fossils, scientists are able to form timelines to show how a certain organism evolved, thus proving that evolution is true.
Essentially, scientists could see what an ancestor of an organism looked like, then compare it to its modern form. Scientists could extrapolate with a series of fossils how an ancestor evolved into its present form. Not many of Coyne’s other arguments allow people to examine a timeline of how an organism evolved, and I believe a timeline is essential to proving ancestry, an element of evolution.
I absolutely agree with Henry when he says that fossils are a wonderful proof of why evolution is true. After all, Coyne himself on page 96 provides examples of ancient fossils that closely resemble modern day organisms. For example, an ancient fossilized primate Gigantopithecus blacki this ancient organism is a clear ancestor of the modern ape due to a clear resemblance(www.uiowa.edu). As Coyne points out, the theory behind creationism faces a brick wall when confronted with fossilized similarities. He states that creationism would propose "an endless number of successive extinctions and creations all over the world" (96) - an idea that is clearly rather ludicrous. But besides expanding upon Henry's argument for fossils, I believe that another factor is important as well - if not more important. The geography of life factor.
ReplyDeleteThe geography of life factor actually involves the fossil argument. It is fact that if were to dig up fossils in any given area, we would find those fossils to be similar to the modern organisms living in that area. Coyne makes many examples out of this. By examining continental drift and organism dispersal, we can see that they clearly match up. Further, examining biogeography on islands effectively proved evolution. We learned in class about island biogeography: basically, the closer an island is to the mainland, the larger the island is, the more biodiversity (Campbell 1216). If we look at islands we can examine on key argument: oceanic islands (never connected to mainland) are missing many types of native species that are seen on continents and continental islands (once connected to mainland). Creationism is hard-pressed to explain why these organisms, though they would be successful, have not been placed on oceanic islands, but have on continental islands. Evolution can explain this factor.
When we look at evolution we see that different environments have different effects on an organism. Take the Hawaiian honeycreeper. They demonstrate adaptive radiation as some have curved sharp beaks and others, rounded ones - all depending on the environment. This is easily explained by evolution and natural selection. In certain environments, one trait is a selective advantage over another and has consequently evolved.
I've noted that the geography of life argument and the fossil argument are very sound. However, I would say that all of Coyne's arguments are feasible. None of his arguments really raised any doubts for me.
Finally, all this relates to the theme of evolution - obviously. Coyne proves evolution - the idea that organisms change over time - through his various factors. In particular, the geography of life factor proves that when a population's environment changes, the population will adapt (or migrate/die). This is influenced by natural selection.