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I didn't read the original article, but this write up does not explain the title at all. Evolution works at the genetic level does it not? What is natural selec

I didn't read the original article, but this write up does not explain the title at all. Evolution works at the genetic level does it not? What is natural selection modifying if it is not the genes?

jrochkind1 4y ago
Same question. I could imagine a variety of answers, I don't this it's exactly impossible, but yeah, the actual answer is the interesting thing the title had me wanting, and not getting here! Or I wonder if this popular write-up article just got it's title wrong?
fiftyfifty 4y ago
Someone on here recommended a book called "Wetware: A Computer in Every Living Cell" and it goes into detail but at a fairly layman level explaining how stuff like this works at the biochemical level. Basically we have genes that code for pieces of proteins and those pieces can be combined in millions of different ways to form unique proteins. Feedback systems based on proteins turn individual genes on and off to encourage the production of effective proteins. Essentially we have the ability to evolve and adapt at the protein level without any modifications to our genes. Honestly reading that book really opened my eyes to how complex this stuff really is. Biology is unbelievably robust and flexible well beyond the basic model of evolution that we are taught takes places at the genetic level.
- waynecochran 3y ago
  Thanks -- I will hopefully have time to read more. I don't understand how the turning on and off of genes is passed to the offspring.
yarg 4y ago
Natural selection is the sieve, not the modifier. That quibble aside, there are also epigenetics to consider.
- waynecochran 3y ago
  OK -- now I am more confused. Selection is a sieve that "selects" the "best fit" which, in the long run, brings modification. Epigenetics is just the manifestation of gene expression under different environmental conditions. Still, in the final overview, it is the genes that are passed on to the offspring. What else is there to inherit?
  - yarg 3y ago
    > which, in the long run, brings modification. Not quite. It's the part that filters the ideas, not the part that generates them to begin with. For that you need a source of change. It doesn't even need to be external; DNA is automutagenic (read up on transposons). There's also homologous recombination that exchanges the DNA between the copies of the same chromosome inherited from different parents (if this didn't happen, you couldn't inherit genes from multiple grandparents in a single chromosome). https://en.wikipedia.org/wiki/Homologous_recombination#In_eukaryotes https://en.wikipedia.org/wiki/Homologous_recombination#In_eu...
Hussell 4y ago
The two species share a lot of glue genes, and the properties of their silks differ due to other genes affecting things like the ratios of glue proteins in the silk. Those other genes evolved faster than the glue genes themselves. The title is technically correct, though misleading.

I didn't read the original article, but this write up does not explain the title at all. Evolution works at the genetic level does it not? What is natural selection modifying if it is not the genes?

jrochkind1 4y ago

Same question. I could imagine a variety of answers, I don't this it's exactly impossible, but yeah, the actual answer is the interesting thing the title had me wanting, and not getting here! Or I wonder if this popular write-up article just got it's title wrong?

fiftyfifty 4y ago

Someone on here recommended a book called "Wetware: A Computer in Every Living Cell" and it goes into detail but at a fairly layman level explaining how stuff like this works at the biochemical level. Basically we have genes that code for pieces of proteins and those pieces can be combined in millions of different ways to form unique proteins. Feedback systems based on proteins turn individual genes on and off to encourage the production of effective proteins. Essentially we have the ability to evolve and adapt at the protein level without any modifications to our genes. Honestly reading that book really opened my eyes to how complex this stuff really is. Biology is unbelievably robust and flexible well beyond the basic model of evolution that we are taught takes places at the genetic level.

waynecochran 3y ago
Thanks -- I will hopefully have time to read more. I don't understand how the turning on and off of genes is passed to the offspring.

yarg 4y ago

Natural selection is the sieve, not the modifier. That quibble aside, there are also epigenetics to consider.

waynecochran 3y ago
OK -- now I am more confused. Selection is a sieve that "selects" the "best fit" which, in the long run, brings modification. Epigenetics is just the manifestation of gene expression under different environmental conditions. Still, in the final overview, it is the genes that are passed on to the offspring. What else is there to inherit?
- yarg 3y ago
  > which, in the long run, brings modification. Not quite. It's the part that filters the ideas, not the part that generates them to begin with. For that you need a source of change. It doesn't even need to be external; DNA is automutagenic (read up on transposons). There's also homologous recombination that exchanges the DNA between the copies of the same chromosome inherited from different parents (if this didn't happen, you couldn't inherit genes from multiple grandparents in a single chromosome). https://en.wikipedia.org/wiki/Homologous_recombination#In_eukaryotes https://en.wikipedia.org/wiki/Homologous_recombination#In_eu...

Hussell 4y ago

The two species share a lot of glue genes, and the properties of their silks differ due to other genes affecting things like the ratios of glue proteins in the silk. Those other genes evolved faster than the glue genes themselves. The title is technically correct, though misleading.