521 not 512, according to the article you mention.

> 521 not 512

Rounding to the nearest whole number.

Typing too fast, thanks! The difference probably won't help bridge the millions of years gap though. :-)

Yet we have Neanderthal dna? Oh, right, that's only 40,000 years. Not 1-3 million.

Yea, I wonder how that's reconciled. The Neanderthal DNA comes from a 38k year-old specimen:

> The researchers recovered ancient DNA of Neanderthals by extracting the DNA from the femur bones of three 38,000-year-old female Neanderthal specimens from Vindija Cave, Croatia, and other bones found in Spain, Russia, and Germany.[8] Only about half a gram of the bone samples (or 21 samples each 50–100 mg[1]) was required for the sequencing, but the project faced many difficulties, including the contamination of the samples by the bacteria that had colonized the Neanderthal's body and humans who handled the bones at the excavation site and at the laboratory.

https://en.wikipedia.org/wiki/Neanderthal_genome_project

2^(38000/521)=10^22, so there must be other effects. That Nature article says

> The team predicts that even in a bone at an ideal preservation temperature of −5 ºC, effectively every bond would be destroyed after a maximum of 6.8 million years. The DNA would cease to be readable much earlier — perhaps after roughly 1.5 million years, when the remaining strands would be too short to give meaningful information.

which I don't know how to square with the 521 year figure. I think maybe 521 years is at the high temp?

Isn't half-life dependent on temperature? Perhaps 521 is at higher temps. Also, half-life does not imply full destruction. By definition, it's destruction of half of the molecules. With enough copies, and a low temperature, it could last much longer than 521 years.

I believe it's the half-life for each bond. But 10^22 is plenty high enough that essentially all bond are broken, and certainly not enough left to reconstruct the genome. (You need unbroken sections of certain minimal lengths to statistically reconstruct what was there before.)

I think you're right that it's a temperature thing.

Either that, or it was preserved in amber ;D

Yes. The Neanderthal species supposedly died out about 40k years ago. [1] In this article they talk about a species that may be millions of years older.

[1] https://en.m.wikipedia.org/wiki/Neanderthal

I'm guessing that shotgun sequencing techniques are used -- that is, you don't need full length segments in order to reconstruct significantly long lengths of DNA. Again a guess.

No, they're not used, because they didn't find DNA -- they found rocks. We're dealing with fossils here, not organic matter. Tissue does not last for millions of years.

Bakker notes that lots of what people call dinosaur fossils are in actuality just bone. Fossilization is rarely a complete or perfect process. So this may in fact be bone.

Wasn't a scientist able to extract DNA fragments from dinosaur bones by leaving them in an acidic solution?