5 ms·

I didn't quite know how to interpret "latent ability". Reading the article, apparently yeast used to be multicellular, which is a pretty valid criticism of thi

by lusr 15y ago

I didn't quite know how to interpret "latent ability". Reading the article, apparently yeast used to be multicellular, which is a pretty valid criticism of this experiment having meaningful results in terms of how single-celled organisms evolved into multicelluar organisms.

padobson 15y ago
This comment seems to assume that evolution can only go in one direction - from simple forms of life to more complex ones. If a complex form of life evolves to become simpler and then evolves again to become more complex, then there's just as much to be learned from following a line of evolution that increases complexity.
- lusr 15y ago
  You are absolutely correct, and it's a comment I anticipated, which is why I qualified my original statement: "meaningful results _in terms of_ how single-celled organisms evolved into multicelluar organisms". (Although in fairness, it probably gives a hint and will certainly lead to future experiments that may provide the beginnings of an answer.)
- ars 15y ago
  If you look at those "simpler" forms of life you find that the genes are not gone, but rather they are disabled. An example is Neoteny - the genes for adult forms are still there, but are unused. That's why I don't think much of this experiment - I bet the genes for multi cellular life were already there, and just needed reactivation - which happened randomly (perhaps due to environment, or perhaps they always activate, but just for short times, and this experiment selected for those with the longest or easiest to trigger activation), but no new genes were needed. To do this experiment properly do a DNA sequencing of the original and final forms. And I'm actually quite surprised that they didn't do that - wouldn't it be very useful to know which genes create multi cellular life? But I bet the genetic diff between them is tiny - just enough to activate genes that are already there in the starting yeast.
  - ZenPsycho 15y ago
    DNA isn't quite exactly like a program that you compile into a living organism. The conditions for its reproduction and expression are partially determined by its environment- so a shift from single celled from multi-celled life might not be able to be pinned on any particular gene or set of genes as a direct cause. You might end up with what is essentially the same sequence, with different parts now triggered by a slightly different proportion of a particular protein present within the cellular membrane.

by lusr 15y ago

padobson 15y ago

This comment seems to assume that evolution can only go in one direction - from simple forms of life to more complex ones. If a complex form of life evolves to become simpler and then evolves again to become more complex, then there's just as much to be learned from following a line of evolution that increases complexity.

lusr 15y ago
You are absolutely correct, and it's a comment I anticipated, which is why I qualified my original statement: "meaningful results _in terms of_ how single-celled organisms evolved into multicelluar organisms". (Although in fairness, it probably gives a hint and will certainly lead to future experiments that may provide the beginnings of an answer.)
ars 15y ago
If you look at those "simpler" forms of life you find that the genes are not gone, but rather they are disabled. An example is Neoteny - the genes for adult forms are still there, but are unused. That's why I don't think much of this experiment - I bet the genes for multi cellular life were already there, and just needed reactivation - which happened randomly (perhaps due to environment, or perhaps they always activate, but just for short times, and this experiment selected for those with the longest or easiest to trigger activation), but no new genes were needed. To do this experiment properly do a DNA sequencing of the original and final forms. And I'm actually quite surprised that they didn't do that - wouldn't it be very useful to know which genes create multi cellular life? But I bet the genetic diff between them is tiny - just enough to activate genes that are already there in the starting yeast.
- ZenPsycho 15y ago
  DNA isn't quite exactly like a program that you compile into a living organism. The conditions for its reproduction and expression are partially determined by its environment- so a shift from single celled from multi-celled life might not be able to be pinned on any particular gene or set of genes as a direct cause. You might end up with what is essentially the same sequence, with different parts now triggered by a slightly different proportion of a particular protein present within the cellular membrane.