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Sunday, June 6, 2010

Dinosaur DNA, anyone?

Not yet, and maybe there will never be any in the near future, says John Asara, a pathology instructor at Harvard Med. School. Asara led a team in may 2009 that successfully extracted protiens from two dinosaur fossils discovered in Montana.

The team is sequencing the proteins to investigate how birds are related to dinosaurs. But getting DNA from such fossil proteins is impossible because generic material breaks down thus ruined over time.

"There is very little DNA left in fossils, that are more than 100,000 years old", said Michael Hofreiter, a geneticist at the university of York in UK. "It is fragmented and there is a lot of contamination from other organisms, including bacteria, fungi and usually humans."

Although scientists have successfully recovered prehistoric DNA from other creature, dinosaur fossils are actualy too old to be extracted from. DNA is also unstable unless constantly repaired and recovered inside a living cell, even under optmial preservation conditions, it is imposible that DNA could remain millions of years whithout being deformed and ruined. So it is far from possible that it could pass 65 million years that have passes since dinosaurs extinction.

Despite the lack of dinosaure DNA, generic material has provided many insights into later species, november 2009, researchers at Penn state university announced that they had recovered a large section of the woolly-mammoth genome dated 20,000 to 60,000 year old. Researchers hope that analysis of the recovered DNA will explaine the processes that led species toward its fate nowadays.



The amber has the unique ability to capture small animals, plants
and materials almost perfectly for millions of years.
Just like the movie Jurassic park, it is possible theoretically to extract a DNA
from a blood cell preserved in an amber specimen containing an insect that stung
and sucked blood from an extinct animal like a dinosaur.


Hundreds of prehistoric insects found intact within huge amber deposit

Tue, Oct 26 2010. A 50-million-year-old amber deposit discovered in India holds a cornucopia of perfectly preserved ancient insects, scientists have discovered what is being called the largest amber deposit ever found, and it's loaded with perfectly preserved ancient bugs. The deposit, which is the first to be discovered in India, is probably larger than the current record holders in the amber-rich Baltic region of Russia, Germany, Ukraine and Poland. Even more valuable than the amber itself, however, is the treasure trove of ancient insects found trapped inside. Prehistoric bees, ants, spiders and mites that become encased within the amber over 50 million years ago can now be studied in unprecedented detail.

The bugs found in the new Indian deposit are different from what discovered before. They're some of the best preserved specimens ever found, with surprisingly well-preserved soft tissues.
"We are able to dissolve the amber and get the specimens completely out," said professor Jes Rust of Bonn University in Germany, who pioneered the effort to uncover the insects. "This is really outstanding. It's like getting a complete dinosaur out of the amber and being able to put it under the microscope."

In reality, these 50-million-year-old bugs would have survived the extinction of the dinosaurs, and would have lived at a time before mammals evolved. Though most of the creatures are ancient species, one species of ant belongs to a genus that is still alive today in Australia.
"The amber shows, similar to an old photo, what life looked like in India just before the collision with the Asian continent. The insects trapped in the fossil resin cast a new light on the history of the sub-continent," Rust said. In all, 700 specimens have been found in the amber so far, but scientists say they have only just scratched the surface. "There is an enormous volume of amber to be found. This is just the beginning," added Rust.

In other word, that could be a new hope for extracting a well preserved DNA from such ancient "backups".






What is a DNA anyway
DNA, or "deoxyribonucleic acid", is a molecule contains the genetic code of every living organism. This includes animals, plants, and bacteria. It describe their development, functioning and even the evolution process, just like an "instruction manual" for the cell, the main role of DNA molecules is the long-term storage of information, thought. It is also used by most viruses, which use DNA to infect organisms.
DNA is found in each cell in the organism and tells that cells what proteins to make DNA is found in each cell in the organism and tells that cells what unique proteins to make.

Sources: Science Illustrated and sources.

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1 comment:

  1. Ancient DNA is an awesome concept. Though the chances of any actual DNA remaining are pretty slim; under ideal conditions it is currently estimated to last a few hundred thousand years before it has fully degraded. Even though the amber casing is more ideal than the best preserved mammoths we've found, 50 million years is probably stretching it.

    Also:
    "In reality, these 50-million-year-old bugs would have survived the extinction of the dinosaurs, and would have lived at a time before mammals evolved."

    Huh? These bugs were more than 15 million years old if they survived the event that wiped out the dinosaurs? And the time before mammals evolved; the first mammals lived somewhere between 150 and 200 million years ago (scientists disagree on from what point on an animal can be called a mammal). Surely these bugs didn't grow to be THAT old

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