An Evolution Gene

If we view evolution as a function, it stands to reason that life would be endowed with a tool kit of evolution genes. Such genes would interface with life's architecture to facilitate evolution. That is, while evolution is inevitable in a population of imperfectly replicating cells, the evolution genes would function to effectively catalyze evolution.

But what part of life's architecture might be targeted by these evolution genes? An obvious candidate is the DNA itself, as it is the DNA that codes for the machinery of life. For example, when it comes to the evolution of body plans, evo-devo teaches us that changing the pattern of switches in front of a gene is an integral part of such evolution. The switch sets, in turn, are altered over time through the process of genetic recombination. Recombination can remove switches, add switches, or swap different versions of a switch in or out. Afterwards, natural selection behaves merely as the editor to weigh whether or not such alterations are acceptable.

This entry was posted on Sunday, August 5th, 2007 at 10:37 am and is filed under Evolution, Front-loading. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

9 Responses to “An Evolution Gene”

Thought Provoker Says:
August 5th, 2007 at 4:26 pm
Hi Mike,

In the linked article from your web site you wrote…

A microtubule-like structure is thus in charge of genetic recombination.

Finally, if RecA is an evolution gene, this would lead to an obvious prediction – removal of RecA should compromise an organism's ability to evolve. We'll consider this prediction in the next installment.

Ok, you got my attention. I will be looking into this further.

However, just to make sure I understand correctly, RecA along with the Rad51 and RadA versions are proteins. Isn't this a looser definition of "gene" than strickly "a segment of DNA".

I don't ask this to be a trouble-maker, I ask it to check my comprehension.

Comment by Thought Provoker — August 5, 2007 @ 4:26 pm

Thought Provoker Says:
August 5th, 2007 at 5:00 pm
Hi Mike,

Have you seen this?

http://dfcord.blogspot.com/2007/08/rabbit-vs-snake-most-viewed.html

I thought you might like this.

Comment by Thought Provoker — August 5, 2007 @ 5:00 pm

johnnyb Says:
August 5th, 2007 at 5:08 pm
ThoughtProvoker —

RecA has been long been known to be a requirement for bacterial evolution:

http://jb.asm.org/cgi/content/abstract/179/23/7435

Other interesting papers on this are Barbara Wright's:

http://jb.asm.org/cgi/content/full/182/11/2993
(there was another interesting one by her, but I can't find it at the moment)

Also see anything by Caporale, including this volume for which she is editor:

http://www.nyas.org/annals/detail.asp?annalID=391

Comment by johnnyb — August 5, 2007 @ 5:08 pm

Bilbo Says:
August 5th, 2007 at 5:30 pm
More fascinating stuff, here, Mike. Keep it up!

Comment by Bilbo — August 5, 2007 @ 5:30 pm

Bradford Says:
August 5th, 2007 at 8:38 pm
In other words, recombination occurs because tubulin-like proteins stretch the DNA by forming a dynamically lengthening tube around it. In this way, the growing protein tube can hold onto the single stranded DNA with one "hand" while using its other "hands" to unravel double stranded DNA such that the single-stranded DNA can be used to probe the unraveled DNA for regions that are complementary.

Given its DNA-linked function, its versatility and its universality RecA is a likely tool kit nominee.

A microtubule-like structure is thus in charge of genetic recombination. Finally, if RecA is an evolution gene, this would lead to an obvious prediction – removal of RecA should compromise an organism's ability to evolve. We'll consider this prediction in the next installment.

Good cliffhanger. It is difficult to conceive of life without RecA or at least a functional equivalent. What would a pre-RecA world have been like?

Comment by Bradford — August 5, 2007 @ 8:38 pm

Nick Says:
August 6th, 2007 at 8:41 am
(Not Matzke. Sorry about the ambiguous login ID)

Mike:

Finally, if RecA is an evolution gene, this would lead to an obvious prediction

TP:
However, just to make sure I understand correctly, RecA along with the Rad51 and RadA versions are proteins. Isn't this a looser definition of "gene" than strickly "a segment of DNA".

No, Mike appears to be using a narrow definition of gene (segment of DNA encoding a protein) combined with slightly sloppy editing. The gene that encodes the protein RecA should be designated recA (lowercase italics).

Comment by Nick — August 6, 2007 @ 8:41 am

MikeGene Says:
August 6th, 2007 at 11:34 am
Hi TP,

Y'gotta get up pretty early in the morning to out rabbit me. Behold. But thanks anyway!

Comment by MikeGene — August 6, 2007 @ 11:34 am

Thought Provoker Says:
August 6th, 2007 at 12:41 pm
Hi Nick (not Matze),

You wrote…

The gene that encodes the protein RecA should be designated recA (lowercase italics).

Thank you for the information.

I had assumed a segment of DNA was responsible for the protein but I wasn't sure. That is why I asked the question. Life is full of chicken and egg problems. I am not surprised to see that here too (and don't see it as a significant negative).

Again, thanks.

Comment by Thought Provoker — August 6, 2007 @ 12:41 pm

Thought Provoker Says:
August 6th, 2007 at 12:43 pm
Hi Mike,

You wrote…

Y'gotta get up pretty early in the morning to out rabbit me. Behold. But thanks anyway!

lol I should have guessed. Sorry I didn't notice/remember you had already posted it.

Comment by Thought Provoker — August 6, 2007 @ 12:43 pm

An Evolution Gene

9 Responses to “An Evolution Gene”

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