Innovation; house of cards theory (Introduction)

by David Turell , Thursday, May 14, 2015, 22:25 (3280 days ago) @ BBella

Making large jumps rather then a bunch of little steps:-"Their research suggests that the "house of cards" model—which holds that mutations with large effects effectively reshuffle the genomic deck—explains evolutionary processes better than the theory that species undergo the accumulation of many mutations with small effects.-"'We found this model applied across vast evolutionary time—in yeast, worms and flies," said Jeffrey Townsend,-"Once the crucial role of genes was discovered, most evolutionary biologists conjectured that random mutations in genes were preserved in populations when they helped an organism survive or reproduce. Since mutations that have large effects are almost always fatal to the organism, one classical model holds that most must have small effects and that many would have to accumulate in order to create new traits and forms.-"Another theory hypothesizes the opposite: that mutations do not cause small changes in fitness, but trigger a cascade of changes—the evolutionary "house of cards." A third theory is even simpler: that mutations have no effect on fitness whatsoever. Recent discoveries of how small bits of genetic material regulate expression of large networks of genes bolstered interest in the "house of cards" model, but only now has the theory been successfully demonstrated to be applicable to diverse organisms on a genomic scale."-
 Read more at: http://phys.org/news/2015-05-evolution-house-cards.html#jCp