Wednesday, February 27, 2008

Kimodo Dragons in Kansas Zoo Conceive without Mating

The New York Times reports on female lizards essentially cloning themselves:

Komodos — like many fish, amphibians and reptiles — have lots of reproductive tricks. For example, females can store sperm for a long time, tiding them over when conditions may be poor for reproduction. It’s possible that the Wichita dragon eggs could have been fertilized by the sperm from a male that was on site a long time ago. But DNA analysis of the “miracle embryos” from Britain showed that every bit of their DNA came from the females, and nobody should be surprised if this is also true of the Kansas dragons.

Virgin birth, known to biologists as parthenogenesis (from the Greek, “parthen” meaning virgin or maiden and “genesis,” beginning), has been seen in other species over the years. Some lizards occasionally produce offspring in this way. So do several species of fish, including a female hammerhead shark at the Henry Doorly Zoo in Omaha that produced offspring without a male last year...

The big question these virgin births raise is this: If some females can get along without males, why does any species have males? The reason is simple. With virgin birth, hatchlings are simply genetic duplicates of the mother. In a world of clones, there would not be enough variation for populations to adapt. Virgin birth, then, is a great stopgap measure to ensure the survival of a species, but works against it in the long haul.
Tip to Afua.

2 comments:

Albert said...

Dr. Daryl Dexter is the nation's leading Kimodo Dragon expert. I would recommend this 4 minute interview to know more.

See "The Komodo Dragon" audio links.

Albert said...