Board Thread:General Discussion/@comment-62.255.98.169-20130504143516/@comment-24081142-20131024103033

I'm pretty sure it's explicitly stated somewhere that the toxic fungi were made an essential part of their diet. Presumably this means that they are the only source for some chemical on which the Falmer are dependent. In this case, they may not be affecting DNA - it could be a simple chemical effect, which recurs in every generation because they have no choice but to consume the poison. Also, it might well cause the eyes to not develop properly in unborn Falmer, so the damage may already be done even before any specific individual starts eating it.

As for their surprising marksmanship, considering that everything they own is made from Chaurus, the Falmer must be extremely experienced hunters. I personally would think that their impressive archery is more down to lots and lots and lots of practice, rather than any natural talent.