Can organisms evolve to be more prone to evolve at the molecular biology level?

[selfAdjoint]

This is a current topic of interest, can evolution produce organisms that are more prone to evolve? Doesn't this require group selection?

Here is an http://www.pnas.org/cgi/content/full/95/15/8420 (courtesy of the Gene expression blog) which discusses evolvability at the molecular biology level an illustrates with specific processes. I found it fascinating.

 

[wasteofo2]

It seems to me, a layman, that evolution of evolvability would be possible, though the sort of "rougher" animals who can survive in varied circumstances, surviving with various supplies of food would be better suited to live for long amounts of time. Take sharks for instance, they can kill and eat most anything and many have gone essentially unevolved for millions of years. They're an species who, when faced with new circumstances, is evolved well enough to be able to handle them without changing their essential design. While organisms who were more prone to evolve would react to a slow change well, organisms such as sharks would react to a sudden disruption better (so it would seem).

Take the example of a predacious organism called a zoink, which has a predisposition to mutate frequently and evolve rapidly. In the past, if there was a large supply of prey for it(let's call the prey gonks), it would evolve to be more specialized to catching gonks, being able to catch as much as possible and do so better than any of the competing predators in the area. Other predators, not being able to catch sufficient amounts of the gonks would either die out or catch other prey. If a ferral predator is introduced into the zoink's environment and can catch more gonks than it can, and over the course of a few generations for zoinks, the gonk population is decemated by the ferral predator, the zoinks, as a species, will likely be too specialized to catch other prey well, especially since they drove all the other predators away from gonks and towards other prey.

Bassically: if you evolve too often you'd likely become highly specialized and therefore poorly suited to deal with rapid change, organisms like sharks which can naturally adapt to their surroundings well will flourish more often.

Of course, I'm a high school student, not an ecologist.

 

[selfAdjoint]

Yes, I agree. In one of his later popular books, Steven J. Gould discussed the "bush and spike" pattern in many evolutionary lineages. Early in time there will be a "bush" of many radiating lines, but as time goes on those bushy lines die out and there now turns out to be a single line, or only a very few, that endure. The interpretation is that the bushy lines represent evolutionary changes like your zoink, adapting more and more specially to the various niches in a given environment. But then the environment changes and the over specialized zoinks can no longer compete. Only species which, by chance, evolved some flexibility, can adapt to the new conditions.

 

[Phobos]

I'll have to read that paper.

But offhand, I think the general conclusion you two have above may be a bit different in the bacterial/viral world. There, it seems speciation (or production of new strains) is a valuable and low-cost ability (e.g., overcoming hosts' adapting immune systems, antibiotics, etc...low cost given the large bacterial/viral populations, rapid rate of reproduction, and smaller genetic codes).

IIRC, some bacteria react to stressing environments by reducing their DNA error-correcting mechanisms (thereby increasing the rate of mutation). But I should find a reference to back up this statement.

 

[selfAdjoint]

The points you bring up are discussed in the paper. The author makes a sharp distinction between metazoans and single celled orgonisms, and between eukaryotes and protozoa. In each evolutionary gap he illustrates increasing "standoff" technologies at the molecular level, leading to true information processing (and "macro" in the IT sense) technology in axon/synapse biology in mammalian brains.

 

[wasteofo2]

Originally posted by Phobos
I'll have to read that paper.

But offhand, I think the general conclusion you two have above may be a bit different in the bacterial/viral world. There, it seems speciation (or production of new strains) is a valuable and low-cost ability (e.g., overcoming hosts' adapting immune systems, antibiotics, etc...low cost given the large bacterial/viral populations, rapid rate of reproduction, and smaller genetic codes).

IIRC, some bacteria react to stressing environments by reducing their DNA error-correcting mechanisms (thereby increasing the rate of mutation). But I should find a reference to back up this statement.

I was only talking about animals really, and I suppose plants, fungi and some protozoa would follow my basic example as well.