Sunday, September 28, 2008

It's Darwin-Malthus Day!


AUTHOR: Allen MacNeill

SOURCE: Original essay

COMMENTARY: That's up to you...

Most readers of this blog are aware that next year is the Darwin Bicentennial. It's the 200th anniversary of the birth of Charles Darwin and the 150th anniversary of the publication of the Origin of Species. Regular readers also know that this celebration really started this past July 1st, which marked the 150th anniversary of the joint presentation of Darwin and Wallace's theory of evolution by natural selection at the summer meeting of the Linnean Society in London.

However, what many people don't know is that today is also a very significant anniversary of a crucial development in Darwin's theory of evolution by natural selection. On this day in 1838, Darwin
"...happened to read for amusement 'Malthus on Population,' and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck [him] that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this would be the formation of new species." [Darwin's Autobiography, page 83]

According to his autobiography, Darwin read Malthus' famous essay in the evening, and the idea of natural selection sprang fully formed into his mind: "Here then I had at last got a theory by which to work...", and indeed he had. But Darwin was an extraordinarily cautious man, always seeking to avoid controversy and notoriety. In his autobiography he says,
"...I was so anxious to avoid prejudice, that I determined not for some time to write even the briefest sketch of it."

And indeed, he did not. It wasn't until 1842 that he felt confident enough about his theory to set it down on paper, and it wasn't until two years later that he had this original "pencil sketch of 1842" copied out and put into a form that he felt confidant enough about to share with his closest friends. It was this "Essay of 1844", along with a letter to the American botanist, Asa Gray, that were read at the July, 1858 meeting of the Linnean Society along with Alfred Russell Wallace's unpublished manuscript "On the Tendency of Varieties to Depart Indefinitely from the Original Type", which marks the beginning of evolutionary theory's annus mirabilis.

So, the "evolution revolution" really began on a rainy evening in late September in 1838, when Charles Darwin read Malthus "for amusement"...

...and it's also my birthday.

As always, comments, criticisms, and suggestions are warmly welcomed!

--Allen

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