Evolutionary Process More Detailed Than Believed

Texas A&M University ^ | 16 January 2009 | Texas A&M

[Boxen]

New evidence from a study of yeast cells has resulted in the most detailed picture of an organism’s evolutionary process to date, says a Texas A&M University chemical engineering professor whose findings provide the first direct evidence of aspects, which up until now have remained mostly theory.

Working with populations of yeast cells, which were color-coded by fluorescent markers, Katy Kao, assistant professor in the Artie McFerrin Department of Chemical Engineering, and Stanford University colleague Gavin Sherlock were able to evolve the cells while maintaining a visual analysis of the entire process.

[Coyoteman]

From the article:

“Essentially, we were watching evolution in action,” Kao said. “We’re watching evolution in real time. We’re actually seeing a mutation that shows these things have adapted and seeing their population thrive and expand from this adaptation. This is how evolution works.

“In one of our experiments we were able to see five independent population expansions. We had one adaptive mutation that allowed a population to expand, but before it was able to completely take over another un-mutated population of the same cells acquired a different mutation that allowed it to succeed and impede the expansion of the first population.”

In addition to determining if and when a population acquired an adaptation, Kao also identified the specific adaptations that were acquired. She accomplished this using a DNA-based technology that enabled her to determine the specific locations on the genes of the yeast cells that expressed beneficial adaptations.

What she found was that as populations rise and fall, some of these beneficial adaptations factor into the continued evolution of the organism; others don’t.

Cool!

[muawiyah]

Yup, smart little critters.

BTW, this is not actually new material. We've seen the idea "run backwards" I think last year or so. What happened was a guy found that a bug had a "mutation" that had predecessor mutations still extant in the base population, and there were predecessor mutations for those, but for some of the bugs there were "missing mutations". They seemed to have gone from "base condition" to "highly mutated condition" without apparant intervening steps ~ still, you could check out other bugs in the same batches and find those mutations.

I suspect this particular study was merely to test the hypothesis of the earlier study with extant populations exhibiting a variety of mutations of mysterious origins.

Rather than say "this is how evolution works" I'd suggest they say "see what yeast can do". It's real hard to infer anything from yeast that can be replicated in, for example, cows.

[muawiyah]

Lurking around in the long night of the Arctic, you really don't need a whole bunch of blue cones, but you can really use some extra red cones.

You retain color vision because the rods (measuring contrast or light level) overlap the response wavelengths of blue cones.

To test if your ancestors had that environment for a lengthy period of time draw a hellow line on a white paper. Now, illuminate the room with a blue light. If you cannot see the yellow line, they did. If you can see the yellow line, you are a more primitive type human who has not evolved to his or her full potential.

Oh, yes, the red part ~ if you are a guy you prefer redheads and can check'em out a good 10 miles away!