Wednesday, March 11, 2009

Undesirable evolution can be reversed, scientists show

But it takes repeated near exterminations, based on changed climate or by the genocidally minded, to do it.
In what almost seems like a triumph of neo-Lamarckism, Stony Brook University School of Marine and Atmospheric Sciences Professor David O. Conover has figured out how to reverse evolution in an animal species.
The Secret: want a smaller animal? Kill the largest 90% of that species, let the small survivors breed, then kill the largest 90% of their generation; repeat that through 4 generations and you'll find you have a new subspecies that grows to that size or configuration only. Want a larger animal? Kill off the smallest 90% of them for 4 succeeding generations.
Conover used the tiny fast breeding Atlantic Silverside as his evolution species. The fish travels the shorelines of the Gulf of Maine in large schools, devouring zooplankton and other small items, and themselves being consumed by striped bass, codfish and other fishes and seabirds in season. in addition to being a "forage species" for marine wildlife, it is also subject to heavy commercial exploitation as feedstock for marine aquarium fish food products.

Intensive selective harvesting of the Silversides by commercial netters, leaving the smaller fish behind, seems to have unintentionally genetically reprogrammed they and many other species to grow smaller, said lead author Conover, who subjected successive generations of the fish to the aforedescribed controlled decimations.

"We show that adaptive genetic variation in many traits is finely tuned to natural variation in climate. Much of this variation is caused by a gradient in size-selective winter mortality and involves two- to threefold changes in physiological traits that influence population productivity". ..the pool of genotypes that code for life history traits is a highly dynamic property of populations."
So, if the worst fears of the survivalist types prove true and the global trade industrial transportation system breaks down tomorrow followed by mass disease and starvation, it'll only take until the year 2088 to arrive at the new human subspecies, Homo sapiens minimis , that will be compact, agile and quick maturing. The Minis will be well suited to scavenging the apocalyptic wastelands, and like Verne's Morlocks prey on their bigger genetic relatives.

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