Monday, February 16, 2009

The Malay Archipelago & The Theory Of Evolution

It is interesting to know about the connection between Malaysia and the infamous theory of evolution; whether or not we agree with it is completely another story. Let's hold the thought for now and read my story.

Alfred Russel Wallace, during his tour of the Malay Archipelago between 1854 and 1862, made seminal observations of the distribution of species in the various islands of the group. he discovered that there were two distinct groups of species : the islands to the east are clearly allied to Australia while those nearest the Malay peninsula itself have Asian-type flora and fauna. The two groups approach most closely at the narrow strait separating the island of Bali and Lombok. The inference is that the two groups of islands, while having in many case almost identical physical conditions, had formerly been in close contact with the sources of their respective and very different species. Species divergent within each group seemed to inversely related to the length of time since direct contact with the source had been lost.

In 1855, Wallace was in Sarawak and wrote a paper " On the law which has regulated the introduction of new species" in which he suggests that every species has come into existence " both in space and time with a preexisting closely-allied species". Three years later he wrote the famous essay " On the tendency of varieties to depart indefinitely from the original type", in which he explains the principle of natural selection in the evolution of species. He already knew of Darwin, but not his parallel conception of the identical theory, and asked Darwin's opinion of it. The result was the joint appearance in the Journal of the Proceedings of Linnean Society of Wallace's essay and a extract from Darwin's preparatory work for The Origin of Species. The paper generated little public reaction, and Darwin was persuaded instead to write the longer version of the Origin which eventually appeared in November 1859, with the results that are now well known. Darwin and Wallace retained strong mutual admiration; indeed Wallace's book The Malay Archipelago, published in 1869 is warmly dedicated to Darwin.

Isn't it fascinating ? Now where were we in 1855?

(an excerpt from a lecture by T J Dennis, University of Essex, Feb 1995)

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