Geneticists have confirmed a case of birth without mating in a bonnethead shark, one of the smaller hammerhead species. That makes sharks the fifth major vertebrate lineage with documented virgin births.
The mother bonnethead (Sphyrna tiburo) lives at the Henry Doorly Zoo in Omaha, Neb., far from any males of her kind. Her infant, born nearly 6 years ago, was killed by other fish in the zoo's aquarium. DNA analysis of its preserved tissues revealed no evidence of genes other than its mother's, researchers report online in the Aug. 22 Biology Letters.