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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."
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.
So, we're talking about teleological choices, made by teleological beings, driving a non-teleological process?
~ Whence do you come, slayer of men, or where are you going, conqueror of space?
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.
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?
GPL Deconstructed
So what if we change the environment? That doesn't stop evolution. There are always traits that will give an advantage, and those that will give a disadvantage, and there are always novel ways of combining previous traits that can lead to something new. Evolution has never been about survival, it is about passing on genes. And every organism out there changes the environment. Organisms define the environment: prey to some, predator to others, host to still others. To stop evolution in humanity, one would need to ensure that every human on the planet had exactly the same chance to pass on their genes as every other.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
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.
Engineering is the art of compromise.
Altruistic tendency is considered "fit" when dealing with social animals (anything with packs, herds, or tribes). Empathy helps with altruism. It means we make personal sacrifices in order to help the group as a whole (because the group shares many common genes with us).
Empathy so extreme that it hurts society, such as allocating resources away from growing our numbers to extending the lifespans of the severely disabled is NOT evolutionary altruistic.
A slashdotter who didn't build his own computer is like a Jedi who didn't build his own lightsaber.
Thing is, there are equal numbers for the sexes. Girls like tall guys, so attractive girls will get the tall ones. Unattractive ones will get the short ones. Since there are as many women as men, everyone finds someone to mate with even if they aren't ideal. Since everyone breeds successfully, we *won't* get taller, though you might see a flatting of the bell curve of men think tall women are attractive. There is no "survival of the fittest" as everyone, tall or otherwise, survives to breed.
As long as humans a serial monogamists, this is the way it would go. For animals that are polygamous, it would happen as you say.
The cake is a pie
So, yeah, let's instead believe bogus shiny-happy fairy-tales where surely the biggest advantage was being sexy
Hmm, something seems to have touched a nerve there. So, you don't like the thought about being nice as a selective force? No problem.
Your reasoning isn't entirely wrong; but then again it isn't entirely true either. You seem to want to make evolution something that only favours violence and selfishness, which is a rather one-sided view of the world. I haven't read this particular article, but I am familiar with this topic - it isn't as if this is an entirely new idea.
What is evolution really, when you think about it? One component is the fact that in each generation of organisms, some will survive and have descendants and some won't. It is worth remembering that you don't have to be particularly 'fit' in any way in order to produce desendants, you may just be lucky. The thing about 'fitness' only comes in when you look at it statistically - over time, and over a large population, it makes sense to say that the ones that kept surviving and reproducing had traits that made them more 'fit for survival'. This also means is that at any given point in time there is likely to be a proportion of traits in the population that are not advantageous, just to make that point clear.
Another factor that is worth keeping in mind is that the environment is not something seperate from the population. In the case of human evolution this becomes especially important as our numbers grow; it is not surprising to see that genes that influence our social abilities seem to have evolved rapidly since we began to live in larger communities than the typical family groups we see with other primates. Another area where our sheer force in numbers has been important is in diseases; the more people and the close they live together, the more they will contaminate their environment and the more they will pass on infections etc, so we are under a large pressure when it comes to evolving resistence against infections.
The examples you mention, on the other hand, don't seem to make too much sense. Humans are apes; our great advantage has been adaptability; our teeth and gut are general purpose, we are able to both walk and climb, and we have learned to work together - and it is that cooperative ability that has been our greatest asset, and it is probably also the single greatest factor contributing to the evolution of our intelligence. It has also made us the most efficient hunters on the planet - quite well done for a species that is not a predator.
As for what you call 'bogus shiny-happy fairy-tales' - I assume you mean the idea that things like beauty and altruism play a role in evolution. Well, I'm sorry to upset your view on the world, but they do. Altruism is still one of the things we don't entirely understand from an evolutionary point of view, but we can see it happen, even amongst chimpanzees; ie. it is a FACT. Beauty, on the other hand is not difficult to understand - beautiful people are people who look healthy (ie. likelier to produce good offspring), whose facial expressions are mostly kind (probably better at bringing up succesful offspring) etc etc. Our ide of beauty is a result of evolution and therefore important in evolution. The same goes for our morals - our moral rules are the ones that have been valuable for our survival as species.
You refer to some historical facts or factoids about the Romans etc. However, our written history doesn't stretch much more than about 5000 years, and large scale evolution doesn't happen quite as fast as that, which tends to invalidate your arguments. You may not like the idea that physical beauty is important, so you try paint an ugly picture of mankind; yes, even an ugly man or woman can have sex and thus offspring, but looks are after all only one factor in this - an ugly person may have other traits that make him/her very attractive, such as a caring personality, or high social intelligence. But physical beauty is an important factor f