Richard Dawkins is hosting a four part series on the human genome to be broadcast on BBC radio [The Age of the Genome]. Here's part of the summary for episode 1.
In spite of the advances, there have been some surprises and deepened mysteries. One of the greatest shocks was the finding that we have far fewer genes than scientists had assumed before they read out our genetic instructions. It takes no more genes to make a person than it does to make a simple microscopic worm. What makes a man different from a worm lies more in what researchers now calling the Dark Matter of the genome - 300 million letters of genetic code which work in currently mysterious ways.Note to Richard,
Richard Dawkins is an evolutionary biologist at Oxford University and the author of numerous books on evolution and genetics such as 'The Selfish Gene'. In interviews with scientists who led the initial effort to decode the genome and those who are now at the forefront of genetic research, Richard brings his evolutionary insights and fascination with the universal genetic code of life to illuminate how far we've come, and where we are heading in the Age of the Genome.
Many scientists, including the experts in the subject, expected there to be about 30,000 genes in our genome. They were pretty close to being right. No surprises there.
What makes a man different from a worm is that we have a smallish number of different genes and the genes we have in common are regulated differently. This conclusion comes from studies in developmental biology that were completed before the Human Genome Project began. Differences in regulating gene expression can be easily accomplished by changing a few base pairs in the promoter/enhancer region of the gene. No mystery there. The field is called evolutionary developmental biology and it's based on an understanding of evolution.
The "dark matter" is junk. The sequence of the human genome goes a long way toward proving what was suspected back in 1970. That's not a surprise. It's a prediction confirmed. Everything we know about the evolution of genomes in diverse species is consistent with the idea that much of our genome has no function. Evolution explains pseudogenes, it explains the so-called C-value paradox, it explains transposons and selfish DNA, it explains highly repetitive sequences. The "dark matter" has been exposed to the light of day and it looks like junk.