Peter Morris, Adelaide in Australia asked:
Are humans now de-evolving?
Chris - What he means by that is we keep giving people caesarean sections to help get babies out does this mean that weíre evolving so that women get a narrower and narrower pelves so that in the future they wonít gonna have babies normally.
Kat - Itís an interesting one. Thereís no such term really as de-evolving because weíre all constantly evolving. Humans are changing in result of environmental pressures that are on us. I guess, many, many, many thousands of years if we do carry on medicalising humans so that we donít die of conditions caused by our biology then we might evolve to kind of get round them. For example, Iím not sure about if there is evidence that our appendix is vanishing gradually or not because thatís a common cause of illness. I donít think we really have enough time to tell how the impact of modern medicine which only been around for about a hundred years or so is actually affecting our evolution.
Chris Smith - Undoubtedly, there will be an effect because of course fewer people would die, who would have died otherwise. So, evolution may run more slowly. It may be that we evolve in a different way. One of the pressures has been removed but there are new pressures we have to compensate for the fact that we take less exercise. Actually, we eat more and perhaps not as good for us.
Kat - Weíre constantly evolving. It would be interesting to see how it goes.