Marine biologists at the Queen's University of Belfast have made an interesting discovery: Hammerhead sharks will reproduce parthogenically under the right conditions. One of a number of female hammerhead sharks kept in captivity back in 2001 (yes, it took them this long to finish their research and publish) was reportedly able to produce young without the presence of a male hammerhead, which lead to some consternation. The original hypothesis was that the female in question had stored sperm from an earlier mating, so they took DNA samples from the sharks in the tank and the young and diff'd them to …