Thursday, August 30, 2012

Week 1: Historical Influences on Darwin

1) Jean-Baptiste Lamarck:
Lamarck had the most positive influence over Charles Darwin's theory of Natural Selection in two major ways. Firstly, he was the first person to suggest that a dynamic relationship between species and the environment existed. Secondly, during Darwin's schooling years at Edinburgh, the professors Darwin studied under were outspoken supporters of Lamarck and his theories.
2) Lamarck's major accomplishment in the realm of science was his theory of evolution through the mechanism of inherited acquired traits. Lamarck stated that the external environment directly changed an animal's activity patterns. The change in the species would occur through the use/disuse of body parts and the parts themselves would change or be lost to fit bodily needs.
3) Organisms with better access to resources will be more successful in their reproductive efforts:
The giraffe example of Lamarck's theory supports this particular point. The giraffes who stretch their necks have better access to the leaves and then this acquired trait will be passed on to the giraffe's offspring. As known today, this theory is wrong because the only traits that can be passed genetically are inheritable traits, not acquired ones.
In order for traits to evolve and change, they MUST be heritable:
According to Lamarck's theory, the longer necks acquired by giraffes were inheritable traits that could be passed to their offspring. Again, like the previous point, acquired traits are not inheritable.
Individuals do not evolve. Populations do:
In Lamarck's theory, individual giraffes develop longer necks and then pass this trait off to their offspring. Unlike Darwin's theory, this theory can be interpreted as stating that individuals evolve and then pass of the trait to their offspring.
4) No, Darwin would never have developed his theory without the groundwork laid by Lamarck. Darwin's outlook was highly influenced by Lamarck's theories during his university years, and it can be assumed that his academic interests would not have been developed the same way without Lamarck. Also, Lamarck's theories laid the groundwork for Darwin's theory of Natural Selection, which built off of Lamarck's previous work, eventually superseding it.
5) The attitude of the Church made Darwin cautious about publishing his "On the Origin of Species." Darwin literally waited until the last possible moment to publish his findings and theory, in fear that Wallace would get credit for the theory. The Church's negative outlook on evolution could be stemmed to the first evolutionary theorists being anti-Christian and atheist. They tainted the topic for future newcomers, and Darwin, being part of the established order, had much to lose from publishing something that went against Church teachings.
http://www.ucmp.berkeley.edu/history/lamarck.html