Can Evolutionary Standard Rates Change?

Hello everyone!

I have a question about evolution: If the standard rate of error in DNA polymerase for E. Coli bacteria were to increase or decrease, what would this mean for evolution? I mean, would this be a natural process that would be expected eventually (it is going through an evolutionary change)? Or would it be a detrimental to evolution? Or would it even mean anything at all?

I am not an expert in biology so I thought I would see what everyone thinks.

hopefully we have enough numebrs to assure a mutation countering that occurance…

Wonderer, thanks for the reply, but I’m not sure what you mean - can you explain?

After re-=reading teh question, i think i can add something more.

My rudementary understanding of evolution tells me that evolution can actually be driven by a rate of error in dna. If an error turns out to be successful, and gets passed on to many people, you could call it evolution.

I suppose that an increase in error rate would stimulate more evolution, but then the population would suffer from more genetic defects aswell.

If it decreased more of the population would have healthy genes, but there would be less evolutionary progress.

That’s my guess anyway, be sure not to quote me :slight_smile:

Actually, E. coli do do that! Under certain stress conditions, they start mutating the hell out of their genome to see if they can find a way to survive the selective pressure. Fascinating creatures, they are.

Very interesting… so it is not uncommon for a standard measurement of evolution to change?

Does this mean that the E. coli (or the polymerase - or some other element) is “aware” of danger - that is, it seems that there is a level of conscious decision making within the realm of the bacteria if it can change mutation rates in order to survive under external pressures.

Does this make sense?

I suppose it depends on how one conceives ‘consciousness’, which is actually another thread that is going on in the philo section at this very moment! A bacterium is clearly ‘aware’ of its environment because it can react to it (chemotaxis is a classic example of this), and when it senses certain aspects in its environment, some bacteria will choose to activate this desperation strategy. Not all E. coli in a colony will opt for this strategy, so I suppose one could call it a ‘choice’, especially since individuals within a colony are near-identical in terms of genetics.

That is amazing information…

so does this mean:

  1. If evolution is driven by the standard rate of error of RNA and DNA recombination, and

  2. If this rate of change is “consciously” controlled by the tiny organisms that are “aware” of their environment,

  3. therefore, evolution itself is conscious?

I’d be careful about reifying a concept, much less anthropomorphizing it.

Yes, that’s why I used the quotes for “conscious” and “aware”.

Enzymes and bacteria may not be conscious (whatever we mean by the term) in the same way that humans are conscious, but the behavior - for all practical purposes - is very akin to what we understand to be decision making. In other words, we cannot view microscopic creatures from their own point of view, so we must view them from ours. It would seem that the act of discussing the topic - since we are human - will innevitabley lead to some degree of anthropomorphism. Don’t you agree?

Sure. I actually don’t think the anthropomorphic fallacy is a real fallacy. And as applied to bacteria, I think what you’ve said holds just fine. I just don’t think that labels like those being used should be applied to a theory. That is too idealistic for my tastes and it also mistakes the theory describing a thing for a thing. You know?

Mutation rates can change because environmental factors can effect mutation rates and so can levels of genetic redundancies from errors in cell cycle replication, however despite all that certain polypeptides remain largely unchanged through evolutionary time that we can judge when species split by tiny amino acid differences (they get bigger and even this isn’t 100% accurate because of chance mutation ) its very precise though. Like wise we have some ANCIENT genes, that are so well preserved you can switch them between yeast/humans, things that go back to some of the earliest Eucayotes. So mutation rates can go all over the place, but we still see some areas that are resistant to sweeping change. Say mutation rates for ‘TINMAN’ don’t get passed along often (at least in those cases where physical manifestation is early) because well… they end up much like the OZ tinman lacking a proper heart. (mutated or missing heart “pieces”.

but through genetic redundancies (say having 2 copies or 10 of tinman mean those genes are free to mutate) actually this plays a big role in most complex genomes.

or simple organisms like Bacillus Subtilis 47% of its genome have 1 or more ‘related’ genes. So its a HUGE force in effecting mutation rates, Huge evolutionary power.

I’m talking about gene duplication if i’ve never mentioned that among other things.