Saturday, September 11, 2010
Creature Feature: Bdelloid Rotifers.
Back in microbiology class, we looked at some pond water beneath a microscope. Among our fauna to look for were rotifers- single-celled animals so named because of their circular mouths ("rota" meaning "wheel" in Latin). That, and they swim around as though they are driving little cars.
This little thing is like Speed Racer on drugs, swear.
I had no idea that rotifers had such interesting sex lives...or lack thereof.
Bdelloid rotifers do not have sex. At all. They have not had sex for 80 million years.
This is not the first time that parthenogenesis (yes, all rotifers are female) has come up on this blog. It was especially common during Lizard Week. Many invertebrates can self-fertilize, reproduce simply by being cut in half, or have the junk of both sexes. Animals have some pretty damn freaky ways of mating, so hearing about something that just doesn't get it on period is unusual.
More importantly, how does that work?
One of the main benefits of sexual reproduction is that, in the process, genes mix. This allows for new mutations to pop up every now and then that allow a species to become more or less fit for survival. For an asexual species to not only populate but thrive, there had better be a pretty damn good substitute for gettin' jiggy with it.
They have one. Actually, they have two.
Bdelloids steal genetic material from other organisms. These genes are fully functional; if the original bearer of that gene was poisonous, the rotifer will be, too. Gene swapping is common in bacteria but rare in animals. If it were more common, we'd all be plastic surgeons stealing each other's awesome hair, racks and other talents.
In humans, this has horrible results.
These rotifers are also very hard to kill. They can survive being dehydrated - sometimes even giving birth while in the same state as a Frito−Lay product. Also, out of all the animals in the world, they are the MOST capable of surviving radiation. Hail your new overlords: Rotifers and cockroaches!