Here is a fascinating piece about social spiders. They live together in colonies, where they make huge great fuckoff webs the size of houses. They normally go for mosquitos, but just recently they've been taking chunks out of the individualist theory of natural selection. Here's how.

Life evolves through natural selection, as you all know (frankly, if you're not with me so far you're probably going to run out of steam before the end). Anyone who's anyone understands this, but there has long been a debate as to whether this selection works at the level of the group or the individual. It's been generally agreed for a while that it works at the level of the individual.

The argument most commonly used to justify this position is that of sex ratios. Take seals, for instance. If only ten percent of seals were male, they could still get all the females pregnant, and there'd be lots more baby seals than there actually are.

In fact, fifty percent of seals are male. The males fight, the winners get lots of females pregnant and the losers either die of their wounds or loaf about not having sex. This is clearly inefficient (and I should know), so you might expect natural selection to 'choose' the ninety-ten solution instead. It doesn't, for a very good reason.

Each baby seal has one mother and one father. If you're a male in a ninety-ten species, you have an expected average number of offpsring nine times that of a female. Therefore, a genetic mutation which makes a lady seal more likely to give birth to males would expect to succeed, and be copied down the generations, so a ninety-ten ratio could never be stable. The only stable ratio is fifty-fifty, and that's what you get, even though it's less efficient from the point of view of the whole species.

Ninety percent of social spiders In Ecuador are female. This has seriously screwed up the theory, but they think they have an explanation.

Individualist selection depends on genetic variation within the population. In social spiders, there is almost no variation at all, each spider being virtually a clone of the others, so there's nothing for individual selection to work on. For this reason, group selection wins out, as ninety-ten colonies outbreed fifty-fifty ones, and replace them.

There's an obvious problem here, which is mutation. Any mutation towards making boy spiders would be almost bound to conquer the colony in which it arose. However, it might be that such colonies would fare less well than their ninety-ten rivals, and would die off.

It's going to be an interesting debate to follow. Yes it is. There's a more in-depth discussion here, and I've written other spider related stuff here and here. Yes, I'm scratching a bit as well.

Incidentally, here is Bug Girl's website. Me and Bug Girl both think you could all stand to be a bit more interested in bugs. They should stop eating the Internet though.