Ancient Cave Bear DNA Extracted and Decoded

diamond writes "The BBC reports that 'scientists have extracted and decoded the DNA of a cave bear that died 40,000 years ago.' The sequencing technique could also work for Neanderthals. However, 'the idea of obtaining DNA from dinosaurs, depicted in the film Jurassic Park, remains science fiction.' Also reported by Nature Magazine."

Comments

Anything is possible

[Capt'n Hector]

Never say we won't get DNA from dinosaurs. Just recently some scientists uncoverered a dinosaur bone that wasn't completely fossilized: it was so big that they couldn't transport it, so they cut it in half and found actual flesh in the center! I couldn't find it on google news in 5 seconds, but does anybody else remember this? I think there was a reason they couldn't extract any DNA from this guy, but stranger things have happened. Of course, DNA an entire being does not make, so we won't be able to actually make a living breathing dinosaur but we all know what would happen if we did!

Role of mitochondria and cytoplasm

[G4from128k]

If this is going to work, scientists will need copies of both the DNA in the nucleus AND mitochondria (and ways to synthesize the nucleus and mitochondria of the target organism). Implanting a neanderthal nucleus in a human (or any other) kind of egg will not necessarily create a pure neanderthal clone (we might even need to clone the cytoplasmic contents). A study of cloning fish across species boundaries showed that some very basic physical characteristics (e.g., the number of vertebra in the backbone) were controlled by the mitochondria or cytoplasm of the egg, not by the genes in the nucleus.

It's amazing that they can reconstruct the DNA of long-dead creatures but its also clear that nuclear DNA is not the only information-carrying object in biological organisms.

Re:Role of mitochondria and cytoplasm

[fermion]

This to me is the key point. 20 or 30 years ago we believed many things. We believed that if we put adequate sensors in enough places around the earth, we could perfectly predict weather. We believed that the universe was expanding or contracting at a constant rate, and would not accelerate. We believed that if we had a genertic sequence, we would be able to make an exact duplicate of the organism.

As always in science, the universe mocks our simplifications. We have a gene map, and we discover, IIRC, that relitive angles seem to make a difference. As the parent mentioned, the enviroment can cause major changes in physiology, not always random.

In fact the cloning end is simply the hook to get people interested in these popular aritcles. It seems to me the real interesting thing is that we can clean up a sample enough to say with some certainty that the sequence is of the specified animal. Then it gets interesting.

As we collect more samples, and complete more sequences, we can look at the relationships in the patterns og the genetics at a particular time, and investigate how the genetics changed over time. Would there be better proof that birds are dinosaurs than to map the transition of the genes between the two species? If we can map the genes to certain expressed characteristics, we can have another way to estimate what the world was like at certain times. So, why did dinosaurs mutate to birds?

Furthermore we could have a better estimate of the rate genes mutate. We can look if that rate is constant, and if not what affects the rate. This would allow us to make better guesses of when certain families of a species diverged or combined. This would allow us to make better guesses of where human originated, and when homo sapiens sapiens came into existance. And it would provide further data the exact path to humanity, or, to put in more common terms, at what point the common ancestor diverged into what would become pan and homo, if they did in fact at all.

Like so many things in science, we need the clone distractions to keep the average person from falling asleep, but the reality is really so much more exciting.

didn't they find t. rex soft tissue recently?

[circletimessquare]

http://www.nytimes.com/2005/06/03/science/03dinosa ur.html

now if you tell me that dna will degrade over 70 million years and be unrecoverable, then i will believe you

but if you also tell me that they can recover soft tissue with capillaries and cells visible from 70 million years ago, i wouldn't believe you

but that's what they did

so now i don't know what to believe... isn't some sort of t. rex dna recovery possible after all then? granted, it would be fragmented, but if we are talking dessicated soft tissue, can't the fragments be recovered in some sort of context that might make reconstruction possible?

Re:What A Shame!

[TheScorpion420]

What about this Scientists found remainds of soft tissue(namely bone marrow) inside the thigh bone of a T-Rex. The possibility of extracting DNA from it is indeed very high. Just my 2 and 1/2 cents