Evolving Thoughts

Evolution, culture, philosophy and chocolate! John Wilkins' continuing struggle to come to terms with impermanence... "Humanus sum, nihil humanum a me alienum puto" - Terence

Thursday, February 16, 2006

Cane toad evolution

Hot on the heels of the reports that snakes that prey on frogs and toads are evolving to have smaller jaw gape and a longer body length (and hence intestinal length), as cane toads in the northern region of Australia are toxic, comes a report in Nature that the toads are evolving too. It appears that the toads are travelling further and faster than their ancestors did 40 years ago, when they were introduced. Speed gives the speedy ones an advantage - they have access to "naive" ecosystems, with food availability and mating space that is not heavily crowded.

Their legs are longer, and they have roughly five times the distance cover they had before. But older populations, where this selective advantage is not present, show a decline in leg length. The time since colonisation correlates with this decline. Hate them, or hate them intensely, they are marvellously adaptive.

[Thanks to Julian Lamont for the headsup]