Last month there was an interesting genetics story about the discovery of the zombie gene (or “Jesus gene”*).
IRGM, which may or may not be involved in Crohn’s disease, appears to have reactivated in humans after becoming degraded in our ancestors around 25 million years ago.
It is really interesting – perhaps mostly because we can now actually show that this is the case, and guesstimate an era like 25MYA as the original inactivation.
I don’t think its quite as surprising as its being made out to be. It makes plenty of sense given what we know about how genetics evolve. It’s not too inconceivable that if genes can become inactive through random mutation, that so to can inactive genes become re-activated through a similar process.
Just because a gene is inactivated doesn’t exactly mean it’s going to go straight to gobbleygook. By not actually contributing anymore, that gene has effectively removed itself from any selective pressure – including negative. It won’t be selected to become more inactivated. There is no benefit for an organism to scramble the signal any further.
Actually this discovery might show that their is some benefit in not deliberately scrambling genes that aren’t currently expressed. But is that a benefit that selection can act upon?
*everyone knows Jesus isn’t real though, right, kids?