As if snakes weren’t creepy enough, now there’s scientific evidence proving that copperheads and cottonmouths are capable of virgin births in the wild. That’s right, the females of these species of snakes don’t always require male partners to create little snake babies … they can do it all on their own.
According to this article in Scientific America, parthenogenesis -- asexual reproduction in which embryos develop without fertilization -- is the norm for some vertebrates, such as the New Mexico whiptail lizard. Zoologists have also documented the phenomenon of facultative parthenogenesis -- females of species that usually reproduce sexually, delivering offspring without mating -- by creatures in zoos and aquariums. Birds, sharks, snakes and Komodo dragons have all been documented producing offspring asexually, but until now, only in captivity.
Warren Booth, a molecular ecologist at the University of Tulsa in Oklahoma, has reported the first known case of wild facultative parthenogenesis. He and his colleagues captured wild pregnant copperheads and cottonmouths, which gave birth in the lab. They then looked for possible signs of asexually produced snake litters, which include a large number of failures in development, such as stillborn babies and few viable males. They examined the genetic markers of litters exemplifying these characteristics comparing the genetic makeup of the offspring with the populations from which the snakes were collected. Results indicated that the chance of male contribution was infinitesimally small.
It is not known what spurred the females to reproduce asexually. Isolation from males was most likely not the cause as snakes were collected from habitats with plenty of males. The discovery of asexual reproduction in the wild will no doubt encourage other scientists to search for additional examples.
Were you aware that some snakes and other vertebrates could reproduce asexually?