How do skilled surgeons go about crafting a surgical procedure that will separate twins? That was the challenge faced by those medical experts who prepared to separate Trishna and Krishna, twin girls joined at the head who had been abandoned at an orphanage in Bangladesh. Visitors can watch the entire NOVA program that profiles this most remarkable procedure, and it's a great way to learn about...

This collection of Web sites about twins and twin biology starts with a short feature from The Straight Dope (1), which explains the phenomenon of superfecundation. Next is a more extensive piece from Scientific American (2), offering an interesting look at the role genetics may play in the chance of having fraternal twins. The following Web site contains a brief MSNBC story on the recent findings...