Joined: Jan. 2009
|Quote (afarensis @ Jan. 18 2012,12:57)|
|Experimental Evolution of Multicellularity|
|Multicellularity was one of the most significant innovations in the history of life, but its initial evolution remains poorly understood. Using experimental evolution, we show that key steps in this transition could have occurred quickly. We subjected the unicellular yeast Saccharomyces cerevisiae to an environment in which we expected multicellularity to be adaptive. We observed the rapid evolution of clustering genotypes that display a novel multicellular life history characterized by reproduction via multicellular propagules, a juvenile phase, and determinate growth. The multicellular clusters are uniclonal, minimizing within-cluster genetic conflicts of interest. Simple among-cell division of labor rapidly evolved. Early multicellular strains were composed of physiologically similar cells, but these subsequently evolved higher rates of programmed cell death (apoptosis), an adaptation that increases propagule production. These results show that key aspects ofmulticellular complexity, a subject of central importance to biology, can readily evolve from unicellular eukaryotes.|
I saw Carl Zimmer's article on this in yesterday's NYTimes. He referred to what the researchers did as "natural selection", which seems unfortunate, but other than that it was quite good.
"The . . . um . . . okay, I was genetically selected for blue eyes. I know there are brown eyes, because I've observed them, but I can't do it. Okay? So . . . um . . . coz that's real genetic selection, not the nonsense Giberson and the others are talking about." - DO'L