h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I've seen several articles in magazines and newspapers recently, the upshot of which seems to be that more frogs with various mutations (extra legs, other stuff) are being found. Some seem to think it's a result of pesticides, others that the extra uv from depleted ozone layer is causing chromosome damage. Something about enviormental groups thinking that frogs are more sensitive than most, making them good enviro health indicators. thats all I can remember. Maybe someone else with better memory or willingness to actually go look up?

I'd heard of it too, and I just had a look online. None of the articles I found seemed to be very recent, so there may be new information elsewhere. So far, though, I've run into three or four different theories.

One says this is a natural phenomenon, nothing to worry about, been going on for ages. On the other hand, two herpetologists have said they've never seen anything like the numbers of mutated frogs that are being seen now.

The second theory points to a pesticide, Methoprene. This contains retinoids, molecules which have been used to make animals grow extra limbs in the lab. The guys who make Methoprene say they tried it on frogs at 500 times normal concentration, and it didn't do anything.

The next line of thought is that parasites called trematodes, carried by snails in frog ponds, damage young tadpoles, burrowing into limb buds and splitting them so that they produce more than one limb.

And then there's ultraviolet radiation. UV B may harm the frog's immune system, making it more than usually vulnerable to parasites or disease. This can be handily combined with any of the other theories to suit your taste.
This was all on an ABC news page, though there were other pages, including one at University of Georgia, with the same story.

So, go figure.. your guess is as good as theirs.
Hope the computer problem's getting better. Like your Small Animals entry!

Nora

Here's the ABC site - note it's in 'archive'.
http://archive.abcnews.com/sec...s/science/DailyNews/frogs.html
And here's the UGA:
http://www.uga.edu/~srelherp/ecoview/Eco26.htm