Continuing the discussion from Dabar Conference Paper Confidentially Available:
By the way, I’ve come across a couple of papers this evening, which may be of interest to you:
The study’s most startling result, perhaps, is that nine out of 10 species on Earth today , including humans , came into being 100,000 to 200,000 years ago.
“This conclusion is very surprising, and I fought against it as hard as I could,” Thaler told AFP.
That reaction is understandable: How does one explain the fact that 90 percent of animal life, genetically speaking, is roughly the same age?
Was there some catastrophic event 200,000 years ago that nearly wiped the slate clean? …
Environmental trauma is one possibility, explained Jesse Ausubel, director of the Program for the Human Environment at The Rockefeller University.
“ Viruses, ice ages, successful new competitors, loss of prey —all these may cause periods when the population of an animal drops sharply,” he told AFP, commenting on the study.
“In these periods, it is easier for a genetic innovation to sweep the population and contribute to the emergence of a new species.”
Here’s another related paper:
In genetic diversity terms, Earth’s 7.6 billion humans are anything but special in the animal kingdom. The tiny average genetic difference in mitochondrial sequences between any two individual people on the planet is about the same as the average genetic difference between a pair of the world’s house sparrows, pigeons or robins. The typical difference within a species, including humans, is 0.1% or 1 in 1,000 of the “letters” that make up a DNA sequence…
Another intriguing insight from the study, says Mr. Ausubel, is that “ genetically, the world is not a blurry place. It is hard to find ‘intermediates’ - the evolutionary stepping stones between species. The intermediates disappear.”
Dr. Thaler notes: “Darwin struggled to understand the absence of intermediates and his questions remain fruitful.”
“The research is a new way to show that species are ‘islands in sequence space.’ Each species has its own narrow, very specific consensus sequence, just as our phone system has short, unique numeric codes to tell cities and countries apart.”
Adds Dr. Thaler: “ If individuals are stars, then species are galaxies. They are compact clusters in the vastness of empty sequence space.”
At last, a clear scientific definition of what a species is! It seems the ID crowd are half-right: species don’t blur into one another, even over time, and they arise relatively suddenly. Where they go wrong is in failing to reckon with the power of neutral evolution, as the article makes clear.