Sex evolved to prevent parasite infections, say scientists

Sexual reproduction that involves two partners is far less efficient than self-fertilization — at least, from the perspective of evolution. So why did creatures like humans ever start having sex with each other? According to a new study, we did it to fight parasites. We spoke with the researchers to discover what… » 7/07/11 11:18am 7/07/11 11:18am

It's possible to conceive a son without a father...if you're a chimera

The embryos of a male and female twin can sometimes fuse into a single fetus with both male and female sexual organs. Now an imaginative biologist has figured out how this could lead to conceiving a son without a father. » 10/05/10 10:30am 10/05/10 10:30am