RED DEER ADVOCATE (Alberta) 10 May 05 Korean salamander an exciting discovery
The appearance of a distinctive American salamander species beneath a rock in far-off Korea is the most stunning discovery in the field of herpetology during my lifetime, says an evolutionary biologist at the University of California.
David Wake, 68, is a world-renowned expert on the lowly salamanders that many of us - if we're not too squeamish - have delightedly found in moist, woodsy glades.
He is also the senior author of a report in the journal Nature that unveils a startling find that has placed an entirely new genus and species of American-type salamanders on a continent where no scientist had believed they existed at all.
The new salamander poses a major mystery: How did the tiny lungless amphibians, less than five cm long from snout to tail tip, that live on land and breathe through their moist skin, show up in Asia, where all their distant relatives - who are unknown on any other continent - live in the water, mate in the water and breathe with their lungs? Wake's career has been a long one: He published his first scientific paper nearly 45 years ago, and he hasn't stopped since. But this, he said, is the most exciting and unexpected discovery of my career.
Since the initial discovery, the salamander has been found in at least 16 other Korean sites - prompting Wake to ponder anew the mysteries of evolution, plate tectonics and amphibian genetics.
The salamander story begins with a high-school biology teacher from Illinois named Stephen Karsen who teaches at the Taejon Christian International School in South Korea and who led his class into the woods two years ago to turn over some rocks, just to see what they might find.
As Wake tells it, Karsen and his students found an unusual salamander living in a crevice within a limestone rock. Because Karsen knew that all Asian salamanders live in the water and shun the land, he sent his unusual discovery to his retired zoology professor, Ronald Brandon, of Southern Illinois University in Carbondale.
Brandon didn't recognize the curiously out-of-place find, either, and sent it along to Wake for identification and detailed genetic analysis.
I looked at it, and I was really startled, Wake recalled. It was a plethodont, completely different from the Asian salamanders - with a different tongue, different ankles, a different skull, no lungs at all, and a very special, unique feature unknown in Asia: A set of sensory grooves from its snout to its lip that it uses to detect the pheromones of other salamanders, the faint odors that can act as sex attractants or to mark out a territory or family ties.
The aquatic Asian salamanders, Wake said, are vastly different. They are well known from the fossil record and date back in China and Korea as far back as 175 million to 200 million years ago.
It may well be that the skin-breathing plethodonts - which live almost exclusively in North America, with a few enigmatically showing up in Italy and Sardinia - once also thrived throughout Asia and were driven to extinction there by climate changes long ago, Wake speculated.
His best guess is that because the age-old processes of continental drift have brought the coasts of Asia and North America close together and split them apart many times over millions of years, some species of the American version might well have returned to settle in obscure Asian niches and evolve there. Conversely, the lung-breathing Asian tribes might well have inhabited North America and even Europe at one time, only to go extinct long, long ago.
So exciting is the new find that Wake's post-doctoral researcher, David Vieites, is heading for China's Shandong Peninsula, across the Yellow Sea from South Korea, to turn over more rocks there and, perhaps, to find more versions.