"Lamarck was the first man whose conclusions on the subject excited much attention. This justly celebrated naturalist first published his views in 1801... He first did the eminent service of arousing attention to the probability of all changes in the organic, as well as the inorganic world, being the result of law, and not of miraculous interposition."
-Charles Darwin, Origin of Species pg xv
Lamarck's work and theory of evolution was never respected or credited during his lifetime. Although today he is associated with a "discredited theory of heredity", Charles Darwin, Lyell, Haekel, and other evolutionists acknowledged him as a forerunner of evolution and a great zoologist. Lamarck believed that a change in environment causes changes in the needs of organisms living in that environment which then causes changes in behavior. He developed two laws to support his idea of evolution: 1) The Law of Use and Disuse- Organs and structures that are used become more developed, organs and structures that are not used become smaller and may disappear, 2) The Law of Inheritance of Acquired Characteristics- Changes achieved over an organism's lifetime are pass on to its offspring. Although today we recognize the flaw in the second law in that only changes in sex cells will affect its offspring, Darwin used both laws in his research on evolution.
In the Origin of Species, Darwin notes that the use and disuse theory can possibly aid in natural selection, to which he used the weak eyesight of moles and other cave dwelling animals as an example. Darwin also believed that in order for traits to evolve and change, they must be heritable. Since Darwin's research was conducted before the discovery of Mendel's law in the early 20th century, he was unable to accurately describe how traits we passed on, leaving him no choice but to use Lamarck's use and disuse theory. Darwin also shared the idea that humans choose which organisms successfully reproduce through cultivation, leading to Darwin's "artificial selection".
Without the help of Lamarck, Darwin wouldn't have been intrigued enough to question the probability of change among species, as he stated in his book (pg xv introduction). He was so inspired by the work of Lamarck that he extensively used the same lines in his own book for support of his own theory.
Just as Galileo was attacked for his ideas of the solar system, so did Darwin with his ideas of natural selection. Darwin was afraid to share his ideas with others; not only did his theory conflict with the beliefs of the church, but it also conflicted with the entire natural history of England. It took him years to finally publish his book Origin of Species.
Sources:
Creation Science Association of Brittish Columbia http://www.creationbc.org/index.php?option=com_content&view=article&id=118&Itemid=54
Darwin Online http://darwin-online.org.uk/Variorum/1869/1869-xv-c-1872.html
Jean-Baptiste Lamarck http://www.ucmp.berkeley.edu/history/lamarck.html
Sources:
Creation Science Association of Brittish Columbia http://www.creationbc.org/index.php?option=com_content&view=article&id=118&Itemid=54
Darwin Online http://darwin-online.org.uk/Variorum/1869/1869-xv-c-1872.html
Jean-Baptiste Lamarck http://www.ucmp.berkeley.edu/history/lamarck.html
Daniella,
ReplyDeleteI agree with you that Lamarck had a huge role to play in Darwin's theory of Natural Selection. Without Lamarck's eagerness or curiosity, I don't believe that Darwin would have found the correct way that traits are passed on. I love that you used the quote from Darwin's book because it really shows just how important Darwin thought Lamarck really was to his research.
Great Job!
-Jennifer Sequeira
Great opening quote!
ReplyDeleteGood background discussion. The issue of heredity and evolution are actually two different issues. The use and disuse was not a law of heredity but of evolution. You are absolutely correct, however, that Darwin was a bit stuck when it came to the issue of heredity because he was unaware of Mendel's work (I have heard that Darwin had an unopened copy of Mendel's paper on his desk... not sure if this is true). The current theory of heredity of the time was blending inheritance, such as the "mixing of the blood". The problem with this is that it doesn't allow for traits to retain there form but all uniqueness is blended out. Just think about what happens to soda and milk if you blend them together. You no longer have milk or soda... you have a blended mess!
While I agree that Lamark had a great influence on Darwin, he was not the only one to be thinking about evolution during that time and it is possible that he still would have developed his theory without Lamark. Even Darwin's grandfather, Erasmus, toyed with the idea... it was in the family, so to speak!
How did Darwin's work conflict with the "natural history of England"? That one puzzled me. What were Darwin's specific concerns regarding publishing? What repercussions might he and his family experienced?
Good post.
I agree Lamark had a great influence on Darwin. I also chose to write about the influence Lamark had on Darwin. Lamark was the first man to speak out about these theory's, he got recognition and attention for these topics. I think this recognition influenced Darwin to speak out about his theory's. I liked the information you included in your blog, It really shows the connection between Lamark and Darwin.
ReplyDelete-Danielle Mickels