[lbo-talk] Darwinian evolution only part of story?

Dwayne Monroe dwayne.monroe at gmail.com
Wed Jan 27 13:23:16 PST 2010


Yesterday, I wrote:

Carl Woese is apparently one of the few who, as long as 30 years ago, was moving towards these kinds of conclusions.

...

Which, unfortunately, failed to mention the very important (and earlier) work of Prof. Lynn Margulis, creator of the endosymbiosis theory.

<http://en.wikipedia.org/wiki/Endosymbiotic_theory>

Below, an excerpt from one of her works in which she outlines the differences between her view and that of the 'neo-Darwinists':

LYNN MARGULIS

"Gaia Is a Tough Bitch"

from - <http://www.edge.org/documents/ThirdCulture/n-Ch.7.html>

<snip>

THE neo-Darwinists say that variation originates from random mutation, defining mutation as any genetic change. By randomness they mean that characters appear randomly in offspring with respect to selection: if an animal needs a tail, it doesn't develop this tail because it needs it; rather, the animal randomly develops all sorts of changes and those with tails survive to produce more offspring. H.J. Muller, in the 1920s, discovered that not only do X rays increase the fruit-fly mutation rate, but even if fruit flies are isolated completely from X rays, solar radiation, and other environmental perturbation, a spontaneous mutation rate can be measured. Inherited variants do appear spontaneously; they have nothing to do with whether or not they're good for the organism in which they appear. Mutation was then touted as the source of variation- -that upon which natural selection acted — and the neo-Darwinian theory was declared complete. The science remaining required filling in the gaps in a "theory" with very few holes.


>From many experiments, it is known that if mutagens like X rays or
certain chemicals are presented to fruit flies, sick and dead flies result. No new species of fly appears — that is the real rub. Everyone agrees that such mutagens produce inherited variation. Everyone agrees that natural selection acts on this variation. The question is, From where comes the useful variation upon which selection acts? This problem has not yet been solved. But I claim that most significant inherited variation comes from *mergers* — from what the Russians, especially Konstantin S. Mereschkovsky, called symbiogenesis and the American Ivan Emanuel Wallin called symbionticism. Wallin meant by the term the incorporation of microbial genetic systems into progenitors of animal or plant cells. The new genetic system — a merger between microbe and animal cell or microbe and plant cell — is really different from the ancestral cell that lacks the microbe. Analogous to improvements in computer technology, instead of starting from scratch to make all new modules again, the symbiosis idea is an interfacing of preexisting modules. Mergers result in the emergence of new and more complex beings. I doubt new species form just from random mutation.

Symbiosis is a physical association between organisms, the living together of organisms of different species in the same place at the same time. My work in symbiosis comes out of cytoplasmic genetic systems. We were all taught that the genes were in the nucleus and that the nucleus is the central control of the cell. Early in my study of genetics, I became aware that other genetic systems with different inheritance patterns exist. From the beginning, I was curious about these unruly genes that weren't in the nucleus. The most famous of them was a cytoplasmic gene called "killer," which, in the protist Paramecium aurelia, followed certain rules of inheritance. The killer gene, after twenty years of intense work and shifting paradigmatic ideas, turns out to be in a virus inside a symbiotic bacterium. Nearly all extranuclear genes are derived from bacteria or other sorts of microbes. In the search for what genes outside the nucleus really are, I became more and more aware that they're cohabiting entities, live beings. Live small cells reside inside the larger cells. Understanding that led me and others to study modern symbioses.

[...]

full at --

<http://www.edge.org/documents/ThirdCulture/n-Ch.7.html>



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