Sunday, September 30, 2007

Hypothetical Itch - Evolution

In my random Internet wanderings I came across some quotes from Greg Graffin (lead singer of the band Bad Religion).
"Notions of progress, purpose, emergent properties, optimality, and increasing complexity in evolution all contain vague hints of dualism, and are debated in symposia and published in books and journals by today's most active evolutionists."

Greg's one of my favorite people, punk rock singer turned geologist turned phd in zoology. What's not to love?

This reminded me of a conversation I had earlier in the week about evolution. I don't remember what exactly I was trying to argue about evolution or what the conclusion of that conversation was. But I was trying to make the point that evolution isn't so much a process as it is an observation.

What I think I was trying to get at in that conversation was more or less that evolution had no 'purpose'. It's simply the observation of the effects of Natural Selection, the obvious truth that the most fit for an environment will surivive (and thus favor genetic mutations in that direction).

I was about to go try and re-argue some points here, but then got lost in the fascinating questions of what defines a species and the implications of man's up and coming ability to tinker with genetic code.

So here's a few hypothetical questions and thoughts:

If we clone a squirrel from six or seven thousand years ago and mate it with a modern day squirrel and the offspring reproduce does that then qualify the two original squirrels as the same species etc...?
Is it possible to manufacture a 'multi-purpose' species that is capable of reproducing species x when mated with species x and species y when mated with species y?.

A 'Species' is itself simply a human categorization of groups of organisms that are highly compatible reproductively which up to this point has also meant DNA compatible (Ligers and other hybrids being the extreme case). Can these 'rules' be broken?

Take the ability to reproduce twins. It skips a generation, could we manufacture a 'species' that would alternate radically in form/structure/behavior between generations.

This has wild implications if there was a predator/prey relationship between the two as any ability of one to survive further ensures the ability of the other. Would the 'arms race' of genetic mutation continue? Or would one species become an evolutionary 'dud' in the sense that it no longer needs to evolve (Provided we did no more tinkering)

Natural selection is driven by the idea that a particular generation is better fit to survive and reproduce a (near) copy of itself. However, this 'paradox species' has the odd ability that making itself vulnerable to its reciprocal species increases the ability of the species to proliferate. It does not in fact favor passing on 'copies' of the vulnerable species, so we need to rethink this.

What would make a particular family line best fit? Generally we would think a line that generates a more capable predatory species would then be able to generate the most prey species -> higher probability of a prey species reproducing. However, the inverse is true. A more capable prey species would produce more 'predator species' - > higher probability of predators reproducing. So in fact, the 'dud' evolution would ensure a less fit family line and the 'optimal' family would have highly capable predators and prey. The arms race continues. We could also assert, that it would be to a family's benefit to not eat its own prey offspring as this would also hamper the ability of a family line to survive.

This also answers the question of, 'what if they are both predatory'?.... and then realization, this is essentially a cannibalistic species. However, a cannibalistic species is capable of eating itself out of existence. If there is a 'prey' generation, the food supply is in theory self-sustaining as any other predator/prey relationship.

Even weirder behavior is possible if we consider the possibility that the predator and prey could mate. The species then essentially has simply increased the number of genders. Is there a species with more than two genders (excluding hermaphroditic genders)? Would our paradox species form a 'shepherd' model, a praying mantis/black widow behavior, or a sort of 'colony' structure?

Just can't keep from scratching.