Recent Human Evolution May Have Been Driven By Self-Selection

Slur writes "The New York Times reports an insightful theory of Human evolution that gives credit for our accelerated evolution to the evolving brain. By virtue of our aesthetic and utilitarian preferences we ourselves have been responsible for molding the present human form and consciousness. Applied to other species we call it 'artificial selection,' but the new theory implies we did it all quite naturally, unconsciously, and that the exponential evolutionary acceleration we have achieved as a species in recent time is just what you'd expect. It also suggests that the current lull in our physical evolution is by 'choice' as well."

Comments

Who needs evolution with technology

[Anonymous Coward]

It doesn't matter if we evolve, because we change the environment around us as opposed to adapting to it. Therefore evolution has been irrelevant as a factor of survival since humans learned to use tools.

Re:Who needs evolution with technology

[Toonol]

It's not that one-sided. For example, we've invented cars, and now we drive fast. People with a poor ability to process visual information quickly, project trajectories, and convert that to a decision to turn/brake are going to be selected against. That's just an innate consequence of having developing an automobile.

We are changed our tools, while our tools are changing us. Granted, our tools are changing at a much faster rate...

Re:i was just arguing with some guy

[Raffaello]

This is an oversimplified view of how evolution works. In fact, it's so oversimplified as to be grossly misleading.

Evolution works by *differential* reproductive success. This does not require in any way that we leave the "unfit" out in the snow. Their own genetic disadvantages will see to it that they simply leave fewer offspring.

By intervening directly (the "leave them out in the snow" school) you run the very significant risk that you mistakenly identify as "unfit" individuals whose genomes contain significant survival advantages that would otherwise be passed on in the gene pool.

IOW, not being omniscient, people are likely to identify as "unfit" individuals who they simply don't like, feel threatened by, etc., and prevent from reproducing people who are, in fact, carriers of genes with significant survival value.

It's called "natural selection" for a reason: the inevitable expression of each individual's genome will of necessity result in some individuals leaving more offspring than others. These individuals are, *by definition* the fittest. No need to intervene - it's already taken care of.

Note that in artificial selection, breeders can only select for heritable traits that they observe. In the process they often end up with breeds that carry significant deleterious traits because the breeders were not aware that they were inadvertently selecting for these as well.

It all comes down to humility about our lack of omniscience. Anything short of a complete understanding of all the complexity of the human genome, epigenetics, and how these interact with various past, present and yes, even future environments, will lead to the unintended, but potentially disastrous reduction of variation and loss of genes of significant fitness.

The system (natural selection) works well precisely because there is nothing driving it except the objective reality of navigating the myriad vagaries of life successfully to the goal (from evolution's standpoint) of reproducing. Let's not pretend that we understand all of it fully and interfere with it.

Re:i was just arguing with some guy

[2nd Post!]

What is the benefit to our species as a whole to create genetically wrong humans?

Excuse me?

How about the geniuses with perfectly sound minds but unsound bodies? Like Stephen Hawking?

Are you saying the only value humans have is their ability to survive independently of each other? That children who cannot hunt down a buffalo without the help of a parent, or even a peer, is useless? Yet what is cooperation to achieve things greater than an individual (the space shuttle, the pyramids, the aqueducts of Rome, raising a single child) except "depending on society for the rest of their life"?

Perfectly FIT people depend on society their whole lives! Can you generate your own electricity, recycle your own trash, smelt your own steel, craft your own furniture, etc?

So even genetically wrong people can offer things, such as their minds, their voices, their arts, etc, to humanity. On top of that, their survival broadens our genepool; what if the AIDs resistance virus lies in a mildly autistic child? Or the resistance to the next bird flu pandemic lies in a mildly retarded child?

Medical science kills natural selection

[EmbeddedJanitor]

Natural selection tries to weed out a huge % of the population, but medical science overrides it.

Nature determines that weak and premature infants should die, yet they are kept alive and become adults. Nature determines that some adults should not be breeding, yet fertility drugs override this. Nature determines that various people should die by heart failure etc, but drugs keep them alive.

Sure, these are all good from the emotional point of view of keeping people alive and making childless couples happy etc, but does it really help the human gene pool? Perhaps Mother Nature had a good reason to kill off a weak child or prevent that infertile couple from breeding. The long term impacts can only be known in a few generations.