Thursday, August 28, 2014

Evolution

           The theory that evolution exist was a theory that had been questioned since the late 1700's. George Cuvier was one of the finest minds in history who discovered vertebrate paleontology, and created the comparative method of organismal biology. He had contributed large amounts of research in vertebrate and invertebrate zoology and paleontology. Cuvier was the first scientist to provide firm facts showing that past life forms were extinct. In 1795, Cuvier was invited to Paris by Geoffroy Saint-Hilaire, and was appointed as an assistant, and shortly after became a professor of animal anatomy. Cuvier's scientific theory was that organisms are an integrated whole, and no part of the organism can be modified without impairing the function integrated. He did not believe in organic evolution, and for any changes made to an organism's anatomy it would render it unable to survive. Cuvier had studied mummified cats from Egypt and compared it to their living counterparts showing that there was no difference. The research he conducted was used as support for his claim that life forms did not evolve over time.
(ucmp.berkeley.edu/history/cuvier)
            
            Charles Darwin's theory on traits being passed down from generation to generation through reproduction, was one theory  George Cuvier thought of differently . Cuvier was convinced that by looking at a mummified cat which was mummified an unknown amount of years, and then compared it to a living cat he came up with a theory that life forms don't evolve over time. He has limited his answer to "time", but never states specifically if time was in reference to years, generations or centuries.  This theory seems like a vague answer  to evolution that maybe Charles Darwin discovered to be different. Darwin believed that if the environment is changing, then organisms with the new adaptive traits to the changing environment would have more success with reproduction. The traits can only be obtained by reproduction, and must be passed on from generation to generation. So part of Darwin's theory was that evolution does occur but not within one generation, instead it occurs between several generations.
                
             I think Charles Darwin could not have created his theories of evolution without the theories from George Cuvier. The theories that Cuvier had come up with at the time may have been inspiration for Darwin to test his own theories or challenge the other possibilities regarding evolution. When Cuvier analyzed the difference between the jaw of a mammoth, and a Indian elephant, this type of test is what could have also inspired Darwin to look into evolution. He may have questioned not why the jaws look different, but over time how it evolved into looking different.
           
             When Charles Darwin had read the Bible he was questioning the believe of how all animals and creatures lived on the planet. The Bible suggest that all species somehow appeared on the planet, and did not evolve because they were fixed. His theory was said to be just a theory, and was advised that he should not practice his theories because it was considered to be highly unorthodox. Darwin's theory wasn't necessary against the church, but it mainly went against all of natural history in his time. He knew he could get in trouble, and possibly lose his job if he chose to pursue his theory. Darwin knew the test he conducted, and evidence that was collected would be strong enough to support his theory about evolution.

1 comment:

  1. Very good detail on Cuvier's background and research. One topic I would have liked to have seen addressed relates directly to Darwin's work, namely the rise of new species. Opposition to the idea of evolution aside, Cuvier had a problem. He worked with fossils of extinct species, organisms that no longer existed during his lifetime. He was also aware that fossils of extant organisms were not found in fossil record. So how to explain the disappearance and appearance of species in the fossil record, as well as the current diversity? He presented his theory of catastrophism, which argued that organisms went extinct due to catastrophic events. New organisms were then 'created' to fill that space, which explained (to Cuvier) how new species came to be. It is important to understand why Cuvier felt organisms could not evolve, but it is also important to understand the alternative process he proposed in its place.

    Cuvier was influential, but I caution against giving any scientist too much credit in his influence over another (Malthus and Lyell may be the exception here). Cuvier was one of many trying to explain earth's diversity and the fossil record. He certainly would have influenced Darwin, but I'm not sure if his absence would have prevented Darwin from developing his theory given the other scientists of influence during that time.

    The "just a theory" line is from current times and would have been scoffed at during Darwin's day but scientists who know better (as modern day scientists do as well). But you are correct that Darwin was well aware of how his theory would be perceived when he published (not 'practiced'... it isn't a religion). Also, keep in mind that many scientists also recognized that species were not "immutable", so to argue that Darwin was going against "all of natural history of his time" is overstating the situation... Remember Lamarck? Aside from the impact on his own situation, was there anyone else he was worried about? Did he have concerns over how publishing would impact his family?

    Good start to the course.

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