The recent sequencing efforts of a variety of organisms has been contributing a whole lot to what we know about the genome, and especially the genome's contribution to an organism's form. One thing Paul Nelson (I think) has brought up before is the fact that the contents of the genome might not be as important as how it is read. Todd Wood made similar claims in his paper on biological similarity. Wood made some waves in Creationary camps by suggesting that perhaps chimps and humans originated with the exact same DNA! Now, I don't think that this was the case, nevertheless it is interesting food for thought - might the same DNA lead to two radically different organisms based on how it is interpretted by the organism? And might two very different sets of DNA lead to near-identical organisms based on how it is interpretted?
We keep on finding clues to this puzzle that indicate that this might be an affirmative on both cases.
In the case of voles, we find vast genomic differences between species that have nearly-identical morphology.
In the case of sea urchins, we see that they have genomes that are much more similar to humans than fruit flies are. According to this article:
Sea urchins are closer to human and vertebrates from an evolutionary perspective than other more widely studied animal models, such as fruit fly or worms. The sea urchin, in fact, has 7,000 genes in common with humans [NOTE - this does not mean they are identical, just the same general gene], including genes associated with Parkinson’s, Alzheimer’s and Huntington’s diseases and muscular dystrophy. "Another surprise is that this spiny creature with no eyes, nose or hears has genes involved in vision, hearing and smell in humans,"... [emphases and NOTEs added]
Also striking is the similarity between humans and kangaroos on the genetic level:
"There are a few differences, we have a few more of this, a few less of that, but they are the same genes and a lot of them are in the same order," center Director Jenny Graves told reporters in Melbourne.
Now, for those of you unfamiliar with the evolutionary tree, marsupials and placentals were supposed to have diverged long, long ago, in a small mole- or badger-like creature. But here we have kangaroos and humans having the same genes (again, not necessarily identical) in the same order, which is supposedly the evidence for our descent from apes (note that I know of no scientist who says that we descended from kangaroos, and yet what we have here is very much the same type of genetic evidence).
In any case, the point is that similarities and differences within genomes may mean something else entirely from what we think it means today. Are the fundamental components of body morphology even genetic? Anyway, lots of good questions are lurking around in there.
Todd Wood has been blogging the BSG UK conference, titled Genesis and the Origin of the Species. This latest post links to all of his daily entries. The conference is coming soon to the US! I probably won't get to make it (new child on the way), but it sounds like fun!