Thursday, November 04, 2010

ophidian parthenogenesis


Video - Legend of the Serpent.

BBCNews | A female boa constrictor snake has given birth to two litters of extraordinary offspring.

Evidence suggests the mother snake has had multiple virgin births, producing 22 baby snakes that have no father.

More than that, the genetic make-up of the baby snakes is unlike any previously recorded among vertebrates, the group which includes almost all animals with a backbone.

Our finding up-ends decades of scientific theory on reptile reproduction
Biologist Dr Warren Booth

Virgin births do occur among animals.

Many invertebrates, such as insects, can produce offspring asexually, without ever having mated. They usually do this by cloning themselves, producing genetically identical offspring.

But among vertebrate animals, it remains a novelty, having been documented among less than 0.1% of vertebrate species.

In 2006, scientists discovered that two komodo dragons (Varanus komodoensis), the world's largest lizard species, had produced eggs that developed without being fertilised by sperm - a process called parthenogenesis.

Then in 2007, other scientists found that captive female hammerhead sharks (Sphyrna tiburo) could also reproduce without having sex.

But vertebrates generally reproduce sexually.

Not including genetic material from the father - essentially having just a single biological parent - reduces genetic diversity and makes it more difficult for organisms to adapt to, for example, changed environmental conditions or the emergence of a new disease. Fist tap Dale.