3 ms·

This seems peculiar. I can't understand why, if this relatively straightforward modification in the production of EPSP conferred such a major advantage to the o

This seems peculiar. I can't understand why, if this relatively straightforward modification in the production of EPSP conferred such a major advantage to the organism, that it didn't develop as a result of natural selection. There has to be a downside that this study didn't pick up. Perhaps the change makes the plant more attractive to pests?

tomp 13y ago
A simple reason could be that the gene just never happened to appear in the DNA; natural selection cannot "develop" new genes, in can only "select" which of the existing (combination of) genes are better.
- guard-of-terra 13y ago
  There are several ways how a part of genome can suddently be duplicated with all its genes. That's how every species have different number of chromosomes. I might guess that competitive advantage only apply where weeds are bad: in fields. Before fields there were no advantage to this.
  - jrkatz 13y ago
    Right, but that's not natural selection, that's mutation. Natural selection can pick up on the changes after they've taken place. e.g., There's presumably a gene out there that makes humans twice as intelligent at absolutely zero expense, and although if it were to appear it would be selected for, it it clearly hasn't happened yet. Natural selection can't drive that to occur.
    - guard-of-terra 13y ago
      Is there a gene already in human DNA which would make humans two times smarter if repeated / made more active? That's what happens with weed rice. Btw the answer can be yes. We are no longer constrained by food concerns but our genome does not account for that yet.
- sampo 13y ago
  In this case the gene in question is the EPSP synthase, and it occurs in plants also naturally. The GMO plants just have more of it. Duplicating a gene should be well within the capability of normal evolutionary processes. http://en.wikipedia.org/wiki/EPSP_synthase http://en.wikipedia.org/wiki/EPSP_synthase

tomp 13y ago

A simple reason could be that the gene just never happened to appear in the DNA; natural selection cannot "develop" new genes, in can only "select" which of the existing (combination of) genes are better.

guard-of-terra 13y ago
There are several ways how a part of genome can suddently be duplicated with all its genes. That's how every species have different number of chromosomes. I might guess that competitive advantage only apply where weeds are bad: in fields. Before fields there were no advantage to this.
- jrkatz 13y ago
  Right, but that's not natural selection, that's mutation. Natural selection can pick up on the changes after they've taken place. e.g., There's presumably a gene out there that makes humans twice as intelligent at absolutely zero expense, and although if it were to appear it would be selected for, it it clearly hasn't happened yet. Natural selection can't drive that to occur.
  - guard-of-terra 13y ago
    Is there a gene already in human DNA which would make humans two times smarter if repeated / made more active? That's what happens with weed rice. Btw the answer can be yes. We are no longer constrained by food concerns but our genome does not account for that yet.
sampo 13y ago
In this case the gene in question is the EPSP synthase, and it occurs in plants also naturally. The GMO plants just have more of it. Duplicating a gene should be well within the capability of normal evolutionary processes. http://en.wikipedia.org/wiki/EPSP_synthase http://en.wikipedia.org/wiki/EPSP_synthase