Duplicate genes shaped brain evolution
Safia - The first story that has caught my attention is a double in Cell led by two groups, the first by Evan Eichler and the second by Frank Polleux, and it's basically about what makes us human. They found a gene called SRGAP2 (very catchy) which was duplicated three times in humans and that seems to be what drove the expansion of our brains and led to the evolution of human culture.
Kat - Because this is a gene that's just been copied a few times in the genome and that does happen when things just slightly go awry when cells multiply.
Safia - It does, but you like to think that these small mistakes in evolution may be the difference between hair and auburn hair . But actually, it's quite sobering to think that it's a difference between man and mice.
Kat - Because it's the same protein in mice but it's just one single amino acid different. I find that incredible that maybe that is the difference between our brains and their brains.
Safia - Absolutely and it does beg the question, what on earth is this molecule doing in the brain and how is it functioning?
Kat - But we've had the human genome sequence for quite a few years now. Why didn't they spot this first time around?
Safia - Kat, I think the problem is really, that they didn't have technology that was sensitive enough to pick up small, minute differences. Anything like that was discarded as a mistake or harmless variation. I guess now we have access to high tech next generation deep sequencing which is revealing so much more that it's really beginning to tell us what makes us human, and this is information that the first human genome project missed.