Tuesday, March 07, 2006
What proves Evolution? Chicken Teeth
Besides this news from the NYT's that some 700 regions of the human genome shows that we humans are still evolving, there is this from ABCNews: Scientists were studying the ancestry of birds. The mutant chicken embryos that were studied possess a recessive and lethal trait called talpid2. As embryos, they can survive in eggs for as long as 18 days, but they never make it to the hatching stage (chickens normally hatch after 21 days). During their incubation, these mutant embryos begin to grow nascent teeth, like those found in ancient bird fossils. When Harris and his colleagues "turned on" the talpid2 gene in the oral cavity of a normal chicken embryo, they found that the mutation caused the tissues in the embryo's jaw to initiate the formation of teeth, very much like those belonging to the bird's ancestors. "These results provide clear evidence that these chickens possess the memory of the past; they have retained the ability to make teeth, under certain conditions. What I am describing is evolution." "The results of this experiment hit home, highlighting the potential in our genes to re-form what once existed... As far as I am concerned, this experiment vindicates the theory of evolution as it exposes the evolutionary history of birds. Supporters of intelligent design will have to scramble to explain this one!" Don't worry... they will and it will be as equally theocratic as all other explanations.