A Toxic Cane Toad: Super-quick evolution has allowed the cane toad, above, to invade Australia at a rate of 30 miles per year today, compared with seven miles per year in the 1950s.
Posted on 02/15/2006 1:30:20 PM PST by PatrickHenry
Fat, toxic toads at the leading edge of an Australian invasion have evolved longer legs than those behind the front lines, report biologists.
The alarming discovery not only means the toads can spread more quickly over the continent, but it raises the possibility that under the right conditions, animal evolution can happen in just decades, not eons.
That, in turn, has major implications for animals adapting to global warming, as well as biological pest control projects, which generally take for granted that carefully studied animals introduced to fight off invasive species can not evolve into something troublesome.
The inexorable, seven-decade-long expansion of cane toads from their disastrous introduction to Queensland in 1935 has long been monitored by biologists.
One such biologist was recently driving along a toad-crowded road one night, along the invasion front about 40 miles east of Darwin, when he noticed how desperately the toads were hopping grimly toward him, all facing the same way: into virgin territory.
"It was just like an invasion in a science fiction movie," said biologist Richard Shine of the University of Sydney.
Shine is a snake specialist, but when the toads began heading toward his study area, he decided it would be wise to "know thine enemy" before they arrived, he explained.
So for years Shine and his colleagues have been tracking cane toads, and as a matter of course they weigh the toads and measure them. Those records came in handy when they discovered that some cane toads at the invasion front were covering an unprecedented mile-and-a-quarter (two kilometers) each night.
"Sure enough, there was a pattern," said Shine of their astonishing leg-length discovery.
Not only were the legs of pioneer toads significantly longer, but the same athletic build dies out among toads as areas become more settled.
In other words, there appears to be a great advantage to getting the first crack at virgin territory. That boils down to the opportunity to produce more viable tadpoles that grow up to continue the line. For seven decades now that advantage has been awarded to cane toads with the longest legs. That has lead to the steady breeding of longer and longer-legged toads that can keep beating the crowd.
The disheartening result is that the toad invasion rate has increased from seven miles per year in the 1950s to a whopping 30 miles per year today, report Shine and his colleagues in the Feb. 16 edition of Nature.
The silver lining is that the cane toads are showing how quickly some species can adapt to new environments, a challenge now facing innumerable species worldwide as the global climate warms, said ecologist and rapid evolution researcher David Skelly of Yale University.
"We never think of evolutionary changes happening that fast," said Skelly of his fellow ecologists.
That has to change, because the cane toads are just a high profile case of something that is being seen in many organisms all over the planet, he said.
"It doesn't mean that we have no problem (with climate change) or that all species will be viable," said Skelly. But there is evidence that many species might be more able to adapt than previously believed.
Another place where people have to start thinking about rapid evolution is at the federal and state agencies where they evaluate exotic species for release as biological checks on exotic pests, said Skelly.
Right now those agencies don't consider the possibility that a new exotic species will very likely change in its new environment, for better or worse. It's time they started thinking differently, he said.
"So why are there still frogs?"
Please do. I haven't heard that story in ages ...
Are you a Seattle fan?
I may have to revise some opinions. Not all, but a few.
[We wuz robbed.]
Looks like we've pretty much got the local min and max covered. Don't call 911 yet.
No sense being hasty on changing your opinion.
San Francisco? Opinions all revert!
Were the 49'ers forced to give up their name because of some political nuttiness? :-}
Opinions all revert!
They certainly do.
More like your Wernicke's bundle is what's unglued.
Didn't they mine gold a while back? As for football, no, not for a long while.
Now Seattle plays football! They beat the 11...
J. you're a sharp guy. Glad you're finally seeing the point about evolution as well.
Only if they want to get sued by the 'Psychedelic Toads'.
Thanks for the ping!
It's your turn to find the data and put together a chart. I thought you were still off in a spagetti western somewhere, Wolfie. Glad you're back. ;)
How about the Toxic Toads Road Band? Would they get sued for that?
I think this might be the one he was thinking of. I remember seeing one, too and I found this. Here's the link:
Earth in for another "ice age" in mid-century - scientist
http://www.freerepublic.com/focus/f-news/1573245/posts
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