Babies come from “virgin” mothers
Latest news from the world of reptiles: Female boa constrictors can have babies without having mated.
In the scientific world, it’s known as parthenogenesis, and in a paper in the professional journal Biology Letters, entomologist Dr. Warren Booth documents the case of a boa who gave birth to 22 babies over the last two years, all of whom were female and all born in this way.
Dr. Booth says it’s the first time this has been seen in the world of reptiles, although it’s been observed in sharks, lizards and Komodo dragons.
The discovery was made by DNA analysis of the chromosomes of the mother and babies. There were male boas around, so it would have been quite possible for her to mate with them, but she chose not to.
Humans have X or Y sex chromosomes; two X chromosomes for a female and a Z and a Y for a male.
Snakes and many other reptiles have Z and W chromosomes. Two Zs for a male and a Z and a W for females.
But all the snakes in these litters were WW – which was more evidence of the babies having inherited all their genes from their mother.
“Reproducing both ways could be an evolutionary ‘get-out-of-jail-free card’ for snakes,” Booth said. “If suitable males are absent, why waste those expensive eggs when you have the potential to put out some half-clones of yourself? Then, when a suitable mate is available, revert back to sexual reproduction.”
Boas are among the more primitive species of snake, and Dr. Booth believes this may have some relation to the unusual form of reproduction.
Note: While this discovery was made without harmful research, we note that Zoe does not support captive research on animals.