Sometimes reptiles and other ‘lesser creatures' take my breath away with their miraculous talents. One is the facility of some species to reproduce without a male partner which scientists call ‘parthenogenesis' (Greek for ‘virgin birth'). Although there are males around, females of the common little house geckos found in your homes can give birth without them. Others such as the Butterfly Lizard in Vietnam and the New Mexico Whiptail Lizard in the U.S. have gone one step further and completely eliminated males from their populations; only females have ever been found!
All lizards that procreate by parthenogenesis alone are hybrids of two other sexually reproducing species. Not only has the definition of what makes a species become blurred, but here is a case of a new being created without taking thousands of evolutionary years. The most widespread snake in the world is the miniscule Brahminy Worm Snake. It is the only snake in which the entire species is made of females alone, and researchers are yet to explain if it is a hybrid.
Fatherless births happen in just the small creatures, we thought, so imagine our surprise when in 1995, a two-and-half-foot captive Timber Rattlesnake in Colorado called Marsha Joan had a son, Napoleon. She had never met a male in her 14-year lifetime. The following decade saw immaculate conception occur in a Burmese Python (called Maria) in The Netherlands and Aruba Island Rattlesnakes in the U.S. What triggers such unique reproduction in one snake and not others in the same enclosure? Don't hold your breath for any answers yet.
Appropriately, close to Christmas, 2006, seven baby Komodo Dragons were born to Flora at the Chester Zoo. The seven-year-old dragon had never met a male. Another Komodo, Sungai at the London Zoo had been producing babies two years after her last contact with a male Komodo. Genetic tests of the offspring revealed that the two lizards in separate zoos were producing copies of themselves without sex. Because of their unique sex chromosomes, offspring of such non-matings are usually male.
In another dramatic event just last month, scientists announced that Caramel, a beautiful caramel-coloured Colombian Boa Constrictor at The Boa Store (a pet shop) in Tennessee had produced 22 babies parthenogenetically though there were four males in her enclosure. Owner Sharon Moore says that they suspected something was up when all the babies had the same extraordinary coloration, which is caused by a recessive gene. Under normal (sexual) circumstances, only a few in a clutch would inherit it. Paternity tests clinched the case. However, Caramel was no virgin; she had sexually reproduced before.
Caramel's case was extraordinary on another count as well: the babies were all female. Until now it was thought that parthenogenetic daughters in normally sexual species could happen only in a lab using complicated manipulation techniques. It's just a wee bit ironic that the serpent, an animal that supposedly revealed carnal knowledge to humans in the Garden of Eden, should itself be capable of asexual reproduction!
Two Ganges softshell turtles at the Croc Bank have been laying fertile eggs for the last 15 years without a male. Female turtles are known to store sperm in special seminal receptacles for a few years. If this was the case, then it is by far the longest period of sperm storage known for any vertebrate in the world. But now, after learning about Caramel, Flora, Maria and Sungai, it appears that virgin birth may not be such a rare phenomenon in the reptile world. It will create history if these two turtles turn out to be capable of immaculate conception: no turtle has yet been known to hide this trick up its scaly sleeve.
Merry Christmas!
(The author can be reached at janaki@gmail.com)
