John on November 28, 2005 at 7:51 am
Interesting article in the most recent issue of the journal science. [HT: Grey Thoughts] A new study of a type of marine worm, though to have existed for 600 million years, shows that it’s genes have some surprising similarity to human genes. Specifically, the introns or non-coding portions of the worm’s genes are 2/3 similar to humans. Here’s an announcement of the study from Science Daily website and here is the summary from the paper itself:
Previous genome comparisons have suggested that one important trend in vertebrate evolution has been a sharp rise in intron abundance. By using genomic data and expressed sequence tags from the marine annelid Platynereis dumerilii, we provide direct evidence that about two-thirds of human introns predate the bilaterian radiation but were lost from insect and nematode genomes to a large extent. A comparison of coding exon sequences confirms the ancestral nature of Platynereis and human genes. Thus, the urbilaterian ancestor had complex, intron-rich genes that have been retained in Platynereis and human.
In other words, geneticists studying fruit flies and other insect species may have gotten an incorrect picture of primitive genetic complexity, as these organisms may have lost much of the genetic information they once had. Those familiar with the ID debate will see the importance of the distinction. Loss of genetic information is a very different matter from information gain. If this study can be confirmed, Darwin has a new hurdle, i.e. how to explain all those complex, human like genes in an animal that apparently existed prior to the Cambrian explosion.
Update: Krauze at Telic Thoughts pointed me to this post which looks like a case of Babe calling the shot. He seems to have predicted almost exactly what this study found.
Category: Science & Tech |