I recall something about environmental change and stress leading to increased variation in some species. Can’t remember much but ‘stress’ were the factors in a less than ideal environment that could trigger epigenetic changes or a change in frequency of common mutations. However, in the Galapagos case it could simply be changing conditions weeding out the typical birds faster leaving atypical varieties around to survive a little longer, but not necessarily surviving long term without more change.
The key here, if true, is that mutation is itself a biological process that can evolve. The exact way cell division, fertilization, meiosis, etc operate is subject to change and probably environmental (or at least biological, e.g. hormonal) pressures. I don’t think that’s all that contentious.
But the exact way these things happen can increase or decrease the chance of things like “crossing over” and other avenues of mutation occurring. It’s not unreasonable, to me, to postulate that over time not only did the organisms themselves become more refined, but also the mutation process itself became more resilient and directed.
After all, there’s a much better chance of offspring being successful if they’re more likely to be genetically viable, so an organism not only survives by proxy of its viability in the environment, and its ability to find a mate, but also the likelihood that any given offspring will be viable. There’s an equilibrium between “able to change enough to adapt to a new environment” and “stable enough that not every offspring develops a new, exciting genetic disease.” This is an oversimplification, since the actual mechanisms are probably more fine-grained towards being more likely to allow some mutations over others. These avenues could also include an organism allowing certain mutations to be tried (or, more likely, make it more likely for them to occur) only if certain environmental pressures are met. This is, again, assuming all of this is legit.
Of course, I have no evidence for this, but it does characterize evolution as a “learning system.” There is no entity named “evolution” that’s learning something. If you killed all organisms and started from scratch it would be just as random as it was when the first organism appeared on Earth. It’s merely an observation that as a system, evolution will generally trend towards a more “directed” approach because it’s in some ways a self-correcting process, due to the fact that the primary means of evolution – mutation – can itself mutate and the fitness of the mutation process is as important as the fitness of the rest of the organism as far as propagating the species.
This isn’t an area I know anything about, but in response to both of the above posts [I mean the ones by **Trinopus** and **TriPolar** – I haven’t read the other one yet], could this just be an example of adaptive radiation? That is, not that genetic variations are “varying more widely” than usual, and certainly not that they’re being directed in some way, but simply that normal rates of variation are producing an unusual rate of successful change in a species because of new environmental conditions. Whereas if an ecosystem is stable, the same changes are much less likely to have any survival value and won’t persist, so in a stable ecosystem you would appear to have “slow” evolution.
I tracked down the paper that I think the article is referencing
http://eprints.soton.ac.uk/383509/
Its a bit hard to follow but he seems to be suggesting that it is possible for the evolutionary process to itself evolve. So that for example mechanisms may be set up that allow mutations that affect the same system to be more likely to evolve together.
ETA: what Jragon said (damn ninja)
That would seem likely. I just recalled that other thing that I don’t have any real information about where the pattern of genetic change can be affected by environmental factors also. But I don’t think there was an implication of new mutations occurring, just a change in the frequency of what was already there.
I’m way out of my depth, but from what I’ve been hearing, this isn’t anything standard, but something truly epigenetic. The process of evolution itself can modify itself, and has mechanisms to cope with emergencies.
If so, it’s fascinating. DNA already has such an incredible wealth of information built into it. The whole concept of the immune system is staggering. It isn’t beyond all possibility of belief that DNA has codes for what to do to itself if everything else starts to fail.
Obviously, the “scientific” answer is – more research!