4 ms·

Given DNA is quantised into just four nucleotides -- and I suspect that there is no organism that uses, say, just three -- then wouldn't your statement be trivi

Given DNA is quantised into just four nucleotides -- and I suspect that there is no organism that uses, say, just three -- then wouldn't your statement be trivially true? That is, pick a 1mer of a random nucleotide (A, C, G or T) and there you go. What I suspect you're getting at is, rather, if our DNA contains virus DNA, then presumably that virus' DNA also contains the DNA of organisms it encountered (using the same mechanism), etc. Thus, there ought to be an unbroken history -- albeit probably highly corrupted from successive adaptive mutations -- in our DNA to the first living thing. This wouldn't necessarily be everything, though; just everything we've assimilated.

jeletonskelly 8y ago
Yes, that's sort of what I'm getting at with that leading question. If we accept evolutionary biology then a headline like this wouldn't be all that surprising. All living things converge at the root.
- fifnir 8y ago
  > If we accept evolutionary biology then a headline like this wouldn't be all that surprising.All living things converge at the root. That doesn't mean that everything has already been "invented" at the root.
  - Thrymr 8y ago
    > That doesn't mean that everything has already been "invented" at the root. Exactly. The "classical" view of evolutionary genetics is that new genes develop by mutation, are favored (or eliminated) by natural selection, and exchanged only within the same species by interbreeding. So the family tree of life is a map of how closely organisms are related, and they would share a gene only with the nearby branches of the tree descended since that gene arose. We have long known that the simple model is not complete, prokaryotes (bacteria and archaea) exchange lots of genetic material outside their own "species" (trickier to define for bacteria in any case), but it is becoming more widely recognized that lateral gene exchange happens a lot in all organisms. A recent popular book on the subject is "The Tangled Tree: A Radical New History of Life" by David Quammen.
- Xophmeister 8y ago
  What this article is saying, though, is stronger: It's not just convergence to the root, but also branch merges. While those branches will converge to the same root, they may have diverged significantly (such that today, we recognise them as from totally separate organisms).

jeletonskelly 8y ago

Yes, that's sort of what I'm getting at with that leading question. If we accept evolutionary biology then a headline like this wouldn't be all that surprising. All living things converge at the root.

fifnir 8y ago
> If we accept evolutionary biology then a headline like this wouldn't be all that surprising.All living things converge at the root. That doesn't mean that everything has already been "invented" at the root.
- Thrymr 8y ago
  > That doesn't mean that everything has already been "invented" at the root. Exactly. The "classical" view of evolutionary genetics is that new genes develop by mutation, are favored (or eliminated) by natural selection, and exchanged only within the same species by interbreeding. So the family tree of life is a map of how closely organisms are related, and they would share a gene only with the nearby branches of the tree descended since that gene arose. We have long known that the simple model is not complete, prokaryotes (bacteria and archaea) exchange lots of genetic material outside their own "species" (trickier to define for bacteria in any case), but it is becoming more widely recognized that lateral gene exchange happens a lot in all organisms. A recent popular book on the subject is "The Tangled Tree: A Radical New History of Life" by David Quammen.
Xophmeister 8y ago
What this article is saying, though, is stronger: It's not just convergence to the root, but also branch merges. While those branches will converge to the same root, they may have diverged significantly (such that today, we recognise them as from totally separate organisms).