5 ms·

521 not 512, according to the article you mention.

by lighthawk 11y ago

ceejayoz 11y ago
Typing too fast, thanks! The difference probably won't help bridge the millions of years gap though. :-)
- JoeAltmaier 11y ago
  Yet we have Neanderthal dna? Oh, right, that's only 40,000 years. Not 1-3 million.
  - bjelkeman-again 11y ago
    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 https://en.m.wikipedia.org/wiki/Neanderthal
  - jessriedel 11y ago
    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 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?
    - jharger 11y ago
      Either that, or it was preserved in amber ;D
    - colordrops 11y ago
      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.
      - jessriedel 11y ago
        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.
  - deleted 11y ago
    [deleted]
rkuykendall-com 11y ago
> 521 not 512 Rounding to the nearest whole number.

521 not 512, according to the article you mention.

ceejayoz 11y ago

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

JoeAltmaier 11y ago
Yet we have Neanderthal dna? Oh, right, that's only 40,000 years. Not 1-3 million.
- bjelkeman-again 11y ago
  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 https://en.m.wikipedia.org/wiki/Neanderthal
- jessriedel 11y ago
  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 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?
  - jharger 11y ago
    Either that, or it was preserved in amber ;D
  - colordrops 11y ago
    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.
    - jessriedel 11y ago
      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.
- deleted 11y ago
  [deleted]

rkuykendall-com 11y ago

> 521 not 512 Rounding to the nearest whole number.