>> The premise is that total DNA is the same for all cells in the same >> animal and from one mammal to the other. Lower forms of life have less >> DNA. As some mammals become more complex than others in one area or >> another, the % of DNA devoted to that specialization is greater. This >> leaves a deficit of DNA for other tasks (because total DNA is >> constant). Nutrient synthesis is the expression of one of DNA's tasks. >> If nutrients can be obtained from food and not synthsized, then >> valuable DNA space is saved. >That's interesting, but I wonder if there is any evidence that there is >a lack of space in our DNA. Isn't it possible that our DNA, like our >brain, can still store much more information? [We also know that >some genes are repeated thousands of times] >And the fact that the animals don't synthetize such or such nutrient >doesn't mean that the gene is lost. In fact, many genes still exist >but are not expressed anymore [hens still have genes to build teeth!] I agree. Genetic change doesn't seem to be a zero-sum type thing at all. We seem to carry all sorts of unexpressed genes, kinda like baggage for future evolution. ;) What was more to me interesting were the ideas in the rest of the post about omega3 vs omega6, brain size, etc. Cheers, Kirt