Thursday, December 8, 2011

BIOLOGY: Lynn Margulis & Symbiosis In Cell Evolution

Evolution is no linear family tree, but change in the single multidimensional being that has grown to cover the entire surface of Earth.” -Lynn Margulis, What Is Life?   

Biologist Lynn Margulis died on November 22nd. She stood out from her colleagues in that she would have extended evolutionary studies nearly four billion years back in time. Her major work was  in cell evolution, in which the great event was the appearance of the eukaryotic, or nucleated, cell — the cell upon which all larger life-forms are based. Nearly forty-five years ago, she argued for its symbiotic origin: that it arose by associations of different kinds of bacteria. Her ideas were generally either ignored or ridiculed when she first proposed them; symbiosis in cell evolution is now considered one of the great scientific breakthroughs.

Margulis was also a champion of the Gaia hypothesis, an idea developed in the 1970s by the free lance British atmospheric chemist James E. Lovelock. The Gaia hypothesis states that the atmosphere and surface sediments of the planet Earth form a self- regulating physiological system — Earth's surface is alive. The strong version of the hypothesis, which has been widely criticized by the biological establishment, holds that the earth itself is a self-regulating organism; Margulis subscribed to a weaker version, seeing the planet as an integrated self- regulating ecosystem. She was criticized for succumbing to what George Williams called the "God-is good" syndrome, as evidenced by her adoption of metaphors of symbiosis in nature. She was, in turn, an outspoken critic of mainstream evolutionary biologists for what she saw as a failure to adequately consider the importance of chemistry and microbiology in evolution.

As I wrote in the introduction to the first part of the book (Part I: The Evolutionary Idea: "The principal debates are concerned with the mechanism of speciation; whether natural selection operates at the level of the gene, the organism, or the species, or all three; and also with the relative importance of other factors, such as natural catastrophes." These very public debates were concerned with ideas represented by George C. Williams and Richard Dawkins on one side and Stephen Jay Gould and Niles Eldredge on the other side. Not for Lynn Margulis, all the above scientists were wrong because evolutionary studies needed to begin four billion years back in time. And she was not shy about expressing her opinions. Her in-your-face, take-no-prisoners stance was pugnacious and tenacious. She was impossible. She was wonderful.
- John Brockman ("Lynn Margulis 1938-2011, Gaia Is A Tough Bitch:" The Edge, 11.23.2011. Image: Artist rendering of cell structure, 2010.

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