Fiach

This is just a sample of this exciting discovery. Read the whole article at

http://news.nationalgeographic.com/n...lamanders.html

“Scientists like Shubin, Gao, and Carroll say they are attracted to the study of salamanders because the amphibians give them a window to see how evolutionary mechanisms work.
Salamanders are more than 160 million years old, they have learned to live in a variety of environments, they have one of the largest genomes of any known animal, and researchers know quite a bit about their variation, said Shubin.

"Put all this together and it means we can understand how evolutionary changes to genes and development produce changes in anatomical features such as heads, limbs, tails," he said.

Of practical interest to humans, said Carroll, is the salamander's ability to regenerate limbs. This characteristic is unique among vertebrates. "It suggests the possibility that we may learn something of this capacity from salamanders that could be applied in the case of severe limb damage," he said”

Fiach

MrDarwin

Already mentioned here. There are so many cool fossils coming out of China lately that it's hard to keep up.

RBH

From the pic of the fossil I saw, it looked just like the ugly lilttle mud puppies we used to catch in creeks in southern Minnesota, right down to the external frills of gills!

RBH

Fiach

I will (when I clear it with the Chinese Govt, like to travel there to look at their genetics research labs) get a chance to go to some good fossil areas, if I can convince them I am interested as a geneticist. Right now there is much international tension, and I think I may have to wait until next year. China has never had a love affair with Britain.

Fiach

Fiach

That is what makes the Mudpuppy so fascinating. It has survived for 160 million years, outlasting the dinosaurs because it is so well adapted to its environment and its environment (rivers and streams) is always found somewhere. However it is one of my arguments against the comet hypothesis of the dino extinction. How come the tough hided dinos died out but porous skinned amphibians like salamanders survived the catastrophe, along with wee fragile birds with a high metabolic rate.

I support Bob Bakker's hypothesis of a family or Order specific or susceptibility pathogenic organism (bacterium or virus) selected the dinos and sea reptiles. An ancient plague in 70 million BC not just a comet, possibly both but not the comet alone killed the dinos.

Fiach

Skydancer

Bakker's grasping at straws because he apparently doesn't understand random-walk statistics. A gradual disappearance of rare fossils as you approach the moment of an actual sudden disappearance is exactly what you expect to see (since the -last- appearance of a type of fossil is less and less likely to be found as you get closer to the boundary - more common fossils also tail off, but more steeply, and very common things like brachiopod shells are practically unchanged until the moment of impact), but he insists on interpreting it as an actual gradual disappearance. He then tap-dances around the problem of explaining the K-T iridium layer. The survival of organisms past the collision point depends on two basic traits - small size and either the habit of living in protected burrows, or the ability to hibernate. Small birds and hibernating salamanders, for all their apparent fragility, are more likely to have the numbers and the protection to survive a traumatic event.

Baloo

Forgive me, but I just don't follow the logistics of this. A single Plague able to wipe out an entire Family must hit so hard and fast that every population of every species within the entire family was wiped out. How could such a plague which killed it's hosts so efficiently possibly spread globally?

Fiach

I didn't explain it very well, sorry. Several things were happening at the close of the Cretaceous. There were some climate change and possibly some early development of flowering plants and grasses. Some dino types like Triceratops and others were already in decline a million years before the end of the Cretaceous.

As luck would have the continents were drifting and sea levels dropping. Land bridges formd across the Bering Strait, and possibley from Europe-Greenland-Canada. This led to dinosaurs the only widely migrating animals to travel both ways. After millions of years of isolations they adapted to endemic pathogens but had no immunity to those of other continents. It may not be a single organism but many different ones fairly specific to Dinosaurs but for some reason not affecting birds, pond turtles, non-migratory alligators and crocodiles, frogs, salamanders, snakes, and mammals.

A Comet that brought on a dark winter of many years killing plants would not have killed the big fat Apatosaurs or other giants as quickly as highly metabolic birds who eat more than their weight in a day. It would have been severely damaged amphibians who have porous skins and likely wiped out the insect life on which they fed. But it did not. Dragon flies survived the so-called comet. Mosquitos survived the so-called comet.

A comet may have contributed to the demise of an already sick and diseased dino population. But the Comet hypothesis cannot explaiin the remarkable Order specificity, and the inexplicable sparing of orders of more fragile animals.

Bakker (Museum of the Rockies) postulates land bridges and mixing of pathogens to unprotected populations.

Fiach

EddieR

Thank you very much for the data about the new discovery in China. Optimistically, the research on limb regeneration will be advanced by the study on the Salamander fossil.

Moreover, this is more evidence that the Peoples Republic of China is socially responsible to the scientific communties of the world. And as a scientific socialist Republic is promising to be quite awesome in the future, too.

EddieR