As New Scientist reports, Canadian and US-American researchers have discovered how modification of one gene may have given early multicellular organisms the competitive edge. The research, published in the journal Molecular Biology and Evolution, shows that a gene, regA, which helps a unicellular alga (Chlamydomonas) to survive in tough conditions, prevents somatic cells of the multicellular alga Volvox from dividing. The gene, involved in gene transcription regulation, is switched on in the single-celled, ancestral Chlamydomonas under severe stress, e.g., lack of light or nutrients. The gene apparently helps the alga conserve energy and survive during lean times, giving it a better chance of living to reproduce under better conditions. In the multicellular Volvox, regA is permanently switched on in the non-reproducing cells, but not in the larger reproductive cells. Thus, one or several mutations in the gene led to a shift from temporal to spatial gene expression, supporting reproductive altruism.
This paper is a great example for modern evolutionary biology. It exemplifies the way evolution is thought to often operate: evolution takes advantage of a genetic make-up and modifies it just enough to convey greater fitness to the variant carrying the modification. It is easily conceivable that once a lump of previously single-celled algae, stuck together by some (un-)fortunate mutation (maybe in a gene on the surface of the membrane), developed the divison of labor we see in today's Volvox (probably by modifications in the regA gene), they would have a significant advantage over similar lumps, which did not divide labor.
For creationists, this must be hard to swallow, as it shows, again, how simple genetic changes can lead to drastic evolutionary developments, in this case reproductive altruism in the first multicellular organisms. The authors go on to refer to similar processes being proposed to have lead to the division of labor in social insects.
With good stuff like this cropping up basically every other month or so, it'll probably take another year (probably less ) before all the silly "intelligent design" examples of what evolution can't explain yet, have gone up in smoke