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.
You've just proven my point.
Tell it to webster's unabridged.
To put it more simply, the Dictionary reflects the language, the language does not reflect the dictionary. Words in common usage seldom reflect their technical usage.
Anyone with even a small understanding of Evolution and its relation to genetics would understand that de-evolution, or devolution as some say, would take a reversal in the sequence of mutations and selection that occurred in the originating evolutionary path. De-evolution is used in common language by those with little understanding.
Bossy, bossy.
Just because you can put together a list of definitions (that nobody reads) doesn't mean you've set the terms. Common usage will prevail.
Not in a scientific context it won't.
The precision needed in science is lost when the word is used as part of common language.
What would an evolution believer know of science?
It was clever!
Precision? If you want precision change your name to "4151.8828125 Hertz". No, with some words and term preciseness counts. For example "femur" rather than "leg bone". With words such as "theory" or "evolution" such precision is folly. As foolish as demanding that your gas station meter the pumped gas to the nano-liter.
Not only were the legs of pioneer toads significantly longer, but the same athletic build dies out among toads as areas become more settled.
Huh? What? Did you find ancient clay tablets recording the results of standardized intelligence tests? How could you possibly know this?!?!? Especially that humans were "considerably" more intelligent circa 2500 BC?
As to stature, where you getting that? What population specifically are you claiming exhibited greater stature? And what modern population do you propose comparing them to?
So far this article gives some of the LARGEST stature measurements I can find from your time period. For a group of 24 Sicilian MALES it gives a mean stature of 169 centimeters. That's only 5' 5".
Toxic Toads would be an excellent name for a band.
Say in 1828. And here's a Merriam Webster definition from 1828:
THE'ORY, n. [L. theoria; Gr. to see or contemplate.]That number 4 item -- that IS scientific. Today? Don't think so, science has no way with genuine precision -- that mission is a poor stepsister to tenured and peer-pecked orthodoxy.1. Speculation; a doctrine or scheme of things, which terminates in speculation or contemplation, without a view to practice. It is here taken in an unfavorable sense, as implying something visionary.
2. An exposition of the general principles of any science; as the theory of music.
3. The science distinguished from the art; as the theory and practice of medicine.
4. The philosophical explanation of phenomena, either physical or moral; as Lavoisier's theory of combustion; Smith's theory of moral sentiments.
Theory is distinguished from hypothesis thus; a theory is founded on inferences drawn from principles which have been established on independent evidence; a hypothesis is a proposition assumed to account for certain phenomena, and has no other evidence of its truth, than that it affords a satisfactory explanation of those phenomena.
(Dear Coyoteman Field work is fun especially if one has a flask of good whiskey for the first breakfast's shot of liquid heat.)
Amazingly, it doesn't seem to be taken!
Neither. Evolution is a population phenomena. It's (literal) nonsense to speak about how "evolved" an individual is. It's like asking the temperature of a single molecule.
I fail to see the appropriateness of your analogy.
The term 'evolution' has a very specific meaning within a given field of study. The word in question, 'devolution', as used by non-scientists has no meaning other than as shorthand for a reversal of adaptation.
Uh, no. That's the point of the whole article, that it hasn't "always been that way". Not to the present degree. Did you even read the article?
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. [...] 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.
That, in turn, has major implications for animals adapting to global warming,...
Just read today that homo sapiens are the only species that do not need to evolve to survive in a changing environment, they can adapt their environment to the change. This is kind of scary. Homo sapiens are not doing much to change global warming.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.