Wednesday, April 12, 2006

Yummy mummy - but not what you think

Mothers feed their young. They can do this by providing food before birth, like in an egg yolk, or via a placenta, or after birth, via milk or finding food. Pretty obvious you say, and you're right, but biologists have discovered an amphibian that looks like a worm where mothers let their newborn offspring peel and eat their skin.

The young worms (of the species Boulengerula taitanus) grow specialized teeth to peel and eat the skin. The mothers modify the outer layer of their skin so it is easy to remove and highly nutritious. It doesn't appear to hurt the mothers too much, and that's the key. If they can give up this food without too much harm to themselves, their children should be much better fed, and therefore better equipped to survive in the environment. If it hurt them too much, they wouldn't be able to produce many offspring, since they'd be dead. It's a fine line, and an example of natural selection at its finest.

The study is in this week's Nature (link will come when available). You can read what nature.com, New Scientist and National Geographic have to stay.