4 ms·

It is incredibly stable? We better don't tell evolution.

ajross 14y ago
Error correction redundancy to any level of reliability you want takes log(N) extra storage. My question would be what the access speeds are. If you have to read it by running it through a trillion PCR test tubes, this isn't exactly practical.
- lupatus 14y ago
  Long term, rarely accessed backup?
- drucken 14y ago
  Microfluidics or lab-on-a-chip are the latest advances: http://www.extremetech.com/computing/84340-new-silicon-chip-sequences-complete-genome-in-three-hours http://www.extremetech.com/computing/84340-new-silicon-chip-... The progress in this field has been far better than Moore's Law [1] so it could be very practical. [1] Excellent TED talk on it too by Richard Resnick: http://www.youtube.com/watch?v=u8bsCiq6hvM http://www.youtube.com/watch?v=u8bsCiq6hvM
chc 14y ago
AFAIK, evolution doesn't occur because of some tendency of DNA to just suddenly change out from under you. It happens because of mutation and recombination, both of which are things that are done to the DNA.
option_greek 14y ago
Considering that most of the mutations are random, the same ecc algorithms we currently use should ensure data integrity.
stmartin 14y ago
The case the article was making was for storage on dead cells.
sp332 14y ago
I've got a few trillion cells in my body that say it's incredibly stable.
- refurb 14y ago
  Snarky reply: You've sequences every single one of those cells and confirm that the DNA all matches? Non-snarky reply: There is a huge difference between phenotype stability and genotype stability. Take 100 cells from your body and you'll find hundreds if not thousands of genetic differences between them (single mutations).
  - sp332 14y ago
    There are 3 billion base pairs in each copy of human DNA. Looks like only ~60 of them change from one generation to the next. http://www.nytimes.com/2010/03/11/health/research/11gene.html?_r=1 http://www.nytimes.com/2010/03/11/health/research/11gene.htm... Just making the 4 trillion cells in my body means that each would have to be copied an average of 41-42 times. Probably some cells get replaced more often and others have a shorter path, so I'm not sure how many times DNA is duplicated before it gets to human reproduction. But going with averages: 41 * 3,000,000,000 / 60 means 2,050,000,000 copies per error. That's a few orders of magnitude worse than a modern hard drive but not exactly shabby.
    - natrius 14y ago
      A mutation has to happen in germ cells (the cells that produce sperm and eggs) for it to pass to the next generation.
      - sp332 14y ago
        I know. If a germ cell has DNA that has been copied 41 times (the average that I calculated), and that DNA has accumulated 60 errors, that means 1 error per 2 billion base pairs copied.
        14y ago

Error correction redundancy to any level of reliability you want takes log(N) extra storage. My question would be what the access speeds are. If you have to read it by running it through a trillion PCR test tubes, this isn't exactly practical.

lupatus 14y ago
Long term, rarely accessed backup?
drucken 14y ago
Microfluidics or lab-on-a-chip are the latest advances: http://www.extremetech.com/computing/84340-new-silicon-chip-sequences-complete-genome-in-three-hours http://www.extremetech.com/computing/84340-new-silicon-chip-... The progress in this field has been far better than Moore's Law [1] so it could be very practical. [1] Excellent TED talk on it too by Richard Resnick: http://www.youtube.com/watch?v=u8bsCiq6hvM http://www.youtube.com/watch?v=u8bsCiq6hvM

chc 14y ago

AFAIK, evolution doesn't occur because of some tendency of DNA to just suddenly change out from under you. It happens because of mutation and recombination, both of which are things that are done to the DNA.

option_greek 14y ago

Considering that most of the mutations are random, the same ecc algorithms we currently use should ensure data integrity.

stmartin 14y ago

The case the article was making was for storage on dead cells.

sp332 14y ago

I've got a few trillion cells in my body that say it's incredibly stable.

refurb 14y ago
Snarky reply: You've sequences every single one of those cells and confirm that the DNA all matches? Non-snarky reply: There is a huge difference between phenotype stability and genotype stability. Take 100 cells from your body and you'll find hundreds if not thousands of genetic differences between them (single mutations).
- sp332 14y ago
  There are 3 billion base pairs in each copy of human DNA. Looks like only ~60 of them change from one generation to the next. http://www.nytimes.com/2010/03/11/health/research/11gene.html?_r=1 http://www.nytimes.com/2010/03/11/health/research/11gene.htm... Just making the 4 trillion cells in my body means that each would have to be copied an average of 41-42 times. Probably some cells get replaced more often and others have a shorter path, so I'm not sure how many times DNA is duplicated before it gets to human reproduction. But going with averages: 41 * 3,000,000,000 / 60 means 2,050,000,000 copies per error. That's a few orders of magnitude worse than a modern hard drive but not exactly shabby.
  - natrius 14y ago
    A mutation has to happen in germ cells (the cells that produce sperm and eggs) for it to pass to the next generation.
    - sp332 14y ago
      I know. If a germ cell has DNA that has been copied 41 times (the average that I calculated), and that DNA has accumulated 60 errors, that means 1 error per 2 billion base pairs copied.
      - 14y ago