Saturday, April 26, 2008

Darwin: I Think I've Got It

Darwin has been in the news quite a lot past couple of weeks and not just because of the release of that misleading, "worse than stupid" movie Expelled.

The New York Botanical Garden has launched an exhibit named "Darwin's Garden: An Evolutionary Adventure" which highlights Darwin the botanist and his many works on plants. Cornelia Dean has a piece on this exhibit in the New York Times. The exhibit recreates portions of a typical British garden as Darwin would have seen through the window of his room and on loan from Cambridge and Harvard University are a selection of Darwin's notes, books and sketches on botanical topics. Dr. David Kohn the exhibit curator says about The Origin of Species and Darwin's work on plants:

Though most people associate that book and Darwin’s ideas generally with his voyage to the Gal├ípagos and his study of finches there, his work with plants was far more central to his thinking


plants were the one group of organisms that he studied with most consistency and depth over the course of a long scientific career” of collecting, observing, experimenting and theorizing.

I knew reading Darwin historians that the finches of the Galapagos Island did not provide a eureka moment for Darwin and it took him some time after his return to London in 1836 to start putting together his thoughts on variation, adaptation and transmutation (evolution) into a coherent theory of evolution. I wasn't aware plants played a big role in this early thinking on evolution. But it makes sense since much of his observations on variation and the malleability of organisms relied on domesticated varieties and the effects of artificial selection. Plants would have made a good study material, easy to grow in your garden and manipulate to observe the effects of pollination and hybridization.

The exhibition opens Friday April 25th and runs through June 15th.

Also, Cambridge University has made available online more than 20,000 pages of documents, manuscripts, books and works of Charles Darwin. I went on the website and was lost. Where should one start exploring such an enormous quantity of material? I have settled on exploring -this is really a long term reading project- the Transmutation Notebooks (Notebook B, Notebook C, Notebook D, Notebook E), a series of notes Darwin complied during the period 1837-39 on some core ideas regarding the stability of species, common descent, extinction, variation, adaptation and natural selection. To say that the notebooks represent a "work in progress" has to be the greatest understatement of all. These writings contain the germs of ideas that changed biology and our understanding of life.

An example from Notebook B 1837:

Source: Darwin Online via NYtimes

The first sketch of the tree of life depicting evolutionary relationships and Darwin's rumination on common descent and the role of extinction in producing discrete gaps and degrees of relatedness between groups. There may not have been one big eureka moment for Darwin when all the pieces suddenly fell in place, but conceptualizing evolution as a branching process with a tree geometry must count as a breakthrough in his thinking, one of many "I've Got it" occasions, one piece of the puzzle clearer. The caption reads " I think", which is something the makers of the movie "Expelled" seem not to have done.

1 comment:

  1. It's easy to grow plants in our garden, but the thing that Darwin observed at that time is thinking too ahead. It takes many years to observe all those facts & then come to conclusion.