There's a new edition of the science carnival, Tangled Bank, over at Jim Lemire's blog, "from Archaea to Zeaxanthol".
Jim has linked a lot of interesting science-related writing from the blogosphere, so go and have a look. I do like Greg Laden's post on how mice evidently use pheromones to avoid incestuous breeding.
Though Greg doesn't go there, this raises the question of whether something similar happens in humans. The most popular theory of incest-avoidance with humans seems to be the Westermarck effect, according to which we imprint on the people with whom we grow up in close proximity - whether or not they are actually siblings - and don't feel sexual desire for them later in life. There seems to be a lot of evidence around that such an effect does happen, e.g. when kids are brought up in collectives. A pheromonal protection against inbreeding, whereby we recognise people genetically similar to ourselves, would be neat, but it doesn't seem like it can be the whole story.