June 28, 2007

Evolution: the Great Tinkerer

This week's Science Times was devoted to evolution and covered some interesting aspects, including a long article on Evo-devo.

Wikipedia provides the most concise definition of Evolutionary developmental biology:

"Evolutionary developmental biology ... compares the developmental processes of different animals and plants in an attempt to determine the ancestral relationship between organisms and how developmental processes evolved. Evo-devo addresses the origin and evolution of embryonic development; how modifications of development and developmental processes lead to the production of novel features; the role of developmental plasticity in evolution; [and more].[citing Hall, below]"

The Times elaborates on how different features develop on similar species -- using Darwin's finches as an easily-understandable example. Dr. Cliff Tabin, a developmental biologist at Harvard Medical School, found that bird beaks "expressed a gene known as BMP4 early in development." This enables Darwin's finches, living on the Galápagos Islands, look very different from each other and from other finches -- particularly in the beak. Some, in fact, "... have evolved taller, broader, more powerful nut-cracking beaks; the most impressive of the big-beaked finches is Geospiza magnirostris." (see McGill University's Hendry Lab finch comparison photos to see some stunning differences)

The article goes on to provide examples of evo-devo in fish (cichlids), marsupials & placental mammals, butterflies, and even flowers.

For More Information
* David Corcoran, a Science Times editor, interviews people associated with these stories in the June 26 Science Times podcast(mp3).
* Evo-Devo - Evolutionary Science - From a Few Genes, Life’s Myriad Shapes by Carol Kaesuk Yoon, New York Times, June 26, 2007.
* Science of the Soul? 'I Think, Therefore I Am' Is Losing Force by Cornelia Dean, New York Times, June 26, 2007.
* Darwin Still Rules, but Some Biologists Dream of a Paradigm Shift by Douglas Erwin,
New York Times, June 26, 2007.
* Guest Editorial: Evo-devo or devo-evo — does it matter? Hall, Brian K. Evolution & Development, Volume 2 Issue 4 Page 177-178, July-August 2000.

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