Take me for example. I have glasses. Quite a small diopter, but glasses nonetheless. In ancient times, my eyesight genes would have had a negative "evolutionary" pressure from the environement. I would have had for example a somewhat degraded chance to successfully hunt my food, lower probability of noticing a stalking tiger, and hence a higher chance of dying before getting to reproduce. Namely, my bad eyesight gene would have had a somewhat smaller probability of successfully propagating itself, and hence would tend to disappear relative to the better eyesight genes.
Today, this is not the case of course, given that I can readily obtain glasses, my bad eyesight gene has just as much a chance in propagating itself as the better eyesight gene. Since the bad gene stands an equal chance in reproducing itself, it wont die away. Of course, there are many other examples like that. The most extreme would be of course a hypothetical gene which causes infertility that can be circumvented by other means (e.g., with IVF - In Vitro Fertilization). Such a gene would have died off after a single generation, but can now easily propagate until the end of eternety.
This implies that bad genes can now accumulate without necessarily dying off. Of course, if they don't have any evolutionary preference, i.e., they are "neutral" (e.g., if it just as easy for glass wearing geeks to get married), it would take a long time for such a gene to become important (if it doesn't accidentally die off otherwise), since it would require a random walk in the gene pool for it to become dominant.
Is this bad for humanity? Clearly, if a gene can now propagate itself by an artificial mean, it would be able to do so in the future, it only implies though that we will have to rely on more and more means. That is, it would be progressively more expensive, and complicated to keep the human race "reproducing".
Of course, I am not the first to think about this point. Many years ago, I read a book by Arthur C. Clarke called Imperial Earth. The background story is about a guy who lives on Titan (a moon of Saturn, which happens to be the only planetary moon in the solar system to posses an atmosphere, but that's just an anecdote I couldn't help myself from mentioning), and takes a trip to Earth to clone himself. Why? Because he is totally sterile, and so was his father and grandfather...
Makes you wonder what humanity will look like in say 500 years. Doesn't it?
Human evolution
Nir,
Your comment is interesting, but maybe it's not so simple. The "bad eyesight" example doesn't quite work. Humans (homo sapiens, not counting our ancestors) had gone through a few 100,000 years of evolution by the 17th century, when glasses were invented, yet bad eyesight was still common among humans. If it was such a bad gene, it would have disappeared a long time ago.
But nevertheless, the question of how our "modern" lifestyle will affect the evolution of our species is fascinating. We should just be careful not to jump to easy conclusions!
Take another example: humans are smart, no question about it. But not THAT smart! Yet we value intelligence a lot, and one might wonder why we have not evolved to be even SMARTER! Even a 10% higher average IQ could make a huge difference. But on the other hand, we evolved as hunter gatherers, and even though our intelligence apparently gave us a huge advantage, the physical constraints to be even smarter (larger, heavier brain?) must have outweighed the advantage of being smarter. Our intelligence was "just right" for the lifestyle we have had for tens of thousands of years. But is it still the case, especially since we changed our way of life about 10,000 years ago with agriculture, followed by the industrial revolution? Intelligence is more and more important in today's world. Are we growing smarter? If you think climate proxies are a difficult subjet, imagine how difficult it is to figure out the average IQ of humans 20,000 years ago!
Our Ancestor's Eyesight
This is an interesting topic which I have found difficult to research. Assuming that 50% or so of humans today need eyesight correction, was this the average 500-1000+ years ago. We need to consider the aging population, such that 1000 years ago the average lifespan was about 30 years, and you were a wise elder if you lived to be 50+.
Early astronomers and scientists must have been the few persons with near perfect eyesight. I don't have the worst eyes, but I sure as heck can't see stars at night. Were half the people who assembled Stonehenge wondering what the heck they were doing, since they had no clue about movement of the heavens? I require about -2.75 diopter correction and wouldn't be able to tell friend from foe from 50 feet. Does that mean I would be considered a blind person 1000+ years ago? Would they have allowed me to go on a hunting party?
Getting back to your question about evolution, I think your point is valid. Sickly and defective people are allowed to propagate. Will future generations require more and more medications, vaccinations, antibiotics etc.. I would think so.
RS
You couldn't be more right
I wonder what it will be like 200 years from now when more and more aflictions can be managed and people routinely live to 100 years old. It is no longer survival of the fittest.
Survival of the fittest
The concept of "survival of the fittest" has not changed, just the definition of "fittest." The societal meme of "making glasses" gives one an evolutionary advantage over those who do not possess that meme.
Poorer eyesight, but more alternatives.
I look at it in todays
I look at it in todays terms, different from where the human race started off. Today survival of the fittest in modern societies is really favors the more intelligent. Back then, I think scientists have shown, ancient cultures were more sophisticated than we originally thought. Some things haven't changed since our early beginnings. Survival favors the well rounded individuals, good physical shape and health, above average intelligence, good interpersonal human relations, and a little chaotic luck. So for the so called geeks that excel in academics and technically skilled professions, they already have their intelligence, they just need to work on their physical appearance (exercise), and their social skills which is important to attract a mate, to produce offspring that are worth something.
Now, in modern societies, democracy rules. Which is fine and dandy, everybody gets a fair chance. The sad thing though, uneducated people statistically have more offspring than educated people. This really puts a strain on our already polluted gene pools. I don't know if its right or not, but people are thinking of ways to reduce the number of babies born by stupid people, I think the group is called Population Connection, they strive to educate the third world countries about contraception and all those things. The reason, educated people choose to have less babies, is because of finacial matters, social matters, environmental matters, plus parents with 1 or 2 kids, usually end up raising better children because they can spend more time on focusing their parental energies on educating, caring, loving, discipling and etc, their kids, rather than, if you have 5 kids, your raising lesser quality kids, because you have to split up your energy spent on them.
Now poor uneducated people, usually have more kids, because they don't care about contraceptions, or they think a condom goes against their religion. Or they think the more kids they have, the more money they get from welfare. I still gasp, when I see a Christian family that has 6-10 kids, no offense to anybody. But, I'm just in awe how much of a burden their putting on this already over populated earth, and now they will brain wash their kids to unintelligibly defend Christianity to the death.
Was the above post written by a militant atheist, by any chance?
Firstly: One cannot 'prove' one's own beliefs are any better than anyone elses, and so using remarks such as 'unintellible', and being openly hostile to christians because of what they think is futile. Who's to say they're wrong, and we're right?
Secondly: the 'poor uneducated people' are no less human than the 'educated people', and they have every right to have children. Would a sterilisation program after the 11+ exams be preferred perhaps?
Thirdly: First past the post isn't really democracy, and nor is the use of constituencies either. Votes don't count, and everyone knows it, so regardless of how many poor people there are, the people we want aren't going to get in. Plus the fact that all the parties are simply centrist. ;P
Also: there isn't really any such thing as survival of the fittest. The whole issue of intelligence doesn't determine how long one'll live. 'Survival of the fittest' is now essentially an obselete term, as we don't tend to survive by slaughtering deer now - we just go down to the local supermarket and buy a nicely cut up, and safety-standards approved venison steak.
In theory, I suppose strength through genetic material will be useless in a society that is creating technology at an ever-increasing speed. If we haven't all killed each other in the next two-hundred years, the likely-hood is that we'll have bionic implants: eyes will be suped-up and replaced, people will run faster with exoskeletons; and information will be a thought away. The rich will be the intelligent ones, who are less affected by genetic disorders and disadvantages - they'll be able to afford it. Either that or they'll just have the 'defective' genes removed from their DNA.
~Just a thought.
Free to believe
Everybody is free to believe to whatever. We live in a free world.
Hi, I would like to add
Hi,
I would like to add some information that i found interesting about the propagation of bad genes. Taking up the bad eyesight example, i would like to mention that i once read that Roman archers were selected from a common pool of soldiers depending on whether or not they could spot that one of the stars in the Big Dipper Constellation was infact a double-star - one star revolving round the other (Alcor and Mizar). If they could, they trained as archers and were stationed behind the infantry, much safer than their hapless counterparts who could not see the double stars, were sent in to the infantry and were much more likely to die.
Thanks for reading.