400,000-Year-Old DNA Intact?
|July 25, 2006||Posted by Patrick under Biology, Science|
STOCKHOLM (AFP) – A Swedish-led team of scientists has discovered 400,000-year-old DNA in bear teeth, the Uppsala University in Sweden said.
The team, made up of Swedish, Spanish and German researchers, discovered the remains of the bear in a cave in Atapuerca, northern Spain.
“It is usually hard to find DNA that is older than 100,000 years, and work on fossilized DNA mostly focuses on material that is a few tens of thousands of years old, at most,” team leader Anders Goetherstroem said in a statement.
He said the find “pushed back the frontier” concerning the age of DNA that scientists could work with. “It means that it will be possible to subject a large number of extinct animals to DNA analysis,” he said.
This is pretty much a continuation of the Dinosaur Shocker Post…but now we have a “Bear Shocker”. This was my earlier comment:
Further discoveries in the past year have shown that the discovery of soft tissue in B. rex wasnÃ¢â‚¬â„¢t just a fluke. Schweitzer and Wittmeyer have now found probable blood vessels, bone-building cells and connective tissue in another T. rex, in a theropod from Argentina and in a 300,000-year-old woolly mammoth fossil.
Those four being isolated incidents? Possibly. Then again, itÃ¢â‚¬â„¢s possible that many fossils might contain soft tissues and people havenÃ¢â‚¬â„¢t been looking for it since they assumed it wouldnÃ¢â‚¬â„¢t be there.
So is this just another isolated incident or another bit of the tip of the iceberg? Of course, that Yahoo article “bearly” (yuck, yuck) has any information in it…I’ll look around later to see if I can find a better source.
Scientists have extracted intact bone marrow from the fossilized remains of 10-million-year-old frogs and salamanders.
The finding, detailed in the August issue of the journal Geology, is the first case of fossilized bone marrow ever to be discovered and only the second report of fossilized soft tissue. In June of 2005, scientists announced they had found preserved red blood cells from a Tyrannosaurus rex leg bone.
“It pushes back the boundary for how far [soft tissue] fossilization can go,” said study leader Maria McNamara of University College Dublin in Ireland.
Preserved soft tissue could provide insight into the physiology of ancient beasts that can’t be gleaned from their fossilized bones alone. If scientists could find bone marrow from dinosaurs, for example, it could help resolve the debate about whether the creatures were warm-blooded or not, McNamara said.
The discovery raises hopes for finding soft tissue in other regions and from other animals, including mammals, McNamara says, because the amphibian bone marrow was discovered in an environment vastly different form the one in which the T. rex soft tissue was found.
It’s also possible that already exhumed fossils contain soft tissue, but that they’ve been missed because detection requires breaking the bones apart.
“Any reasonable museum curator isn’t going to let you go around smashing up the bones in their collections,” McNamara told LiveScience.
The researchers are currently testing to see if DNA or other organic molecules were also preserved.