Sharks? Virgin Births?

It was found that female sharks can fertilize their own eggs and give birth without sperm from males. This was according to a new study of the asexual reproduction of a hammerhead shark in the U. S. zoo. They analyzed the DNA of a shark born in 2001 in the Henry Doorly Zoo om Dublin, Ireland. This shark was born in a tank with three potential mothers, none of whom had contact with a male hammerhead for at least three years. The baby was killed within hours of its birth by a stingray in the same tank and the DNA analysis found no trace of any chromosomal contribution from a male partner. Asexual reproduction is common in some insect species, rarer in reptiles and fish but has never been documented in mammals until now. Just to be sure, the scientists analyzed the DNA three times to be sure, using a new technique with new genetic approaches.