Discussion of everything related to the Theory of Evolution.
I have recently become interested in evolution, and I am curious as to what everyone thinks would be possible directions that homo-sapiens may further evolve? I realize that it takes millions of years, and there is a significant chance that we might destroy ourselves before we see any significant change, but I have thought of certain areas that may influence, for the good or bad, our development. Our poor diets (high calorie intake) causes multiple diseases, plastic surgery causes genetic effects on the phenotype to be relatively useless, and our advancements in technology may make our lives easier, but it seems we are creating lifestyles with low activity and isolation.
One guess I have is that we might develop smaller mouths and larger heads (due to development of the brain, but shrinking portion sizes and vitamin supplements may render many of our teeth expendable).
One thing of which I'm pretty certain is that we become very dependant (in the distant future maybe even symbiotic) with machines and technology. Even today man is pretty much bound to certain technological innovations, such as clothes. Without clothes, we would still live in the savannahs. Similarly, soon many if not most people will need some kind of seeing aid, because poor vision is no longer an evolutionarily significant disadvantage due to the invention of spectacles.
Human evolution is very likely to hand in hand with all kinds of technical tools we develope, and in the future they will surely be much more sophisticated than our current "essentials", namely clothes, spectacles and such. Many devices could even obtain their power from the body itself and thus become even more integral part of us. There could be some standard devices every baby gets, like a vaccine/drug pump taking care of vaccination programs and medication in some common infections, and maybe the eyes need be operated right after birth as well, since generations of poor-sighted ancestors have caused most of the babies to be next to blind. Then us humans would upkeep and maintain manufacturing plants for these technical devices bit like termites and some ants upkeep their fungus factories and we would be inseparable: machines and humans - just like termites and mould, algae and fungi, and so on! :)
well, surgery does not cause genetic changes
we're evolving all the time. We are growing taller, the metabolism must change due to changed diets and amount of available food.
Cis or trans? That's what matters.
Naturally surgery does not cause genetic changes, but it may still affect our genes via natural selection. For example, it can allow "poor" genes to remain in the gene pool. This is just an arbitrary example, but if a person carries a gene for an ugly nose that would normally lower his or her chances of getting a partner and kids, this might not be the case if plastic surgery became routine in the future. That is, if almost everyone's nose was remodeled to ideal, beautiful nose, then we would start carrying a lot of "ugly nose" genes that would normally be reduced in the gene pool. That would cause a sort of loop, where the surgery would become more and more integral part of human life, since otherwise people would have hideous noses :)
Interestingly, people in some parts of the world have performed a certain type of "surgery" routinely to all male children for millennia by chopping off the hood of their pecker. I am not aware if men in areas were circumcision is prevalent have accumulated any mutations related to this. They could, for example, have poorer natural immune defence around the genital area because the lack of foreskin prevents most of the microbes from living in the genital area, thus reducing the need of immune defence in the area. And if their children then would not be circumcised, they might be more prone to infections of the genital area because they have evolved to live without the foreskin.
I have been under the impression that the increase in the human average height has been attributed to more nutritious diet, not genetical changes. That is, people in the medieval times could grow pretty much as tall as we do nowadays, but diseases and especially poor nutrition often prevented them from reaching their (genetically) maximum height.
This is supported by the phenomenom that modern day Americans are becoming shorter than their parents because of the poor quality of the average American diet :P
well, that's possible...
Cis or trans? That's what matters.
It is now debatable that humans are actually evolving backwards. To explain this, you know how evolution depends on certain factors, such as, natural selection. Variations in human genetic information is through mutations. As humans are finding ways to "cheat", i.e. the "weak ones" or those with "inferior genes" may still survive and pass on their genes. As such, we would provide a wide gene pool yet with no methods of passing only the best genes on (that is moral, I mean, kill off the weak, and I'll be first on the list!!). To some extent, the "best genes" are more likely to survive, i.e. money+ when genes+, however benefits and monetary help as well as "society being all equal" hinders "culling" of the weak. Hence, I think personally, that Human Evolution is probably occurring mostly in undeveloped countries compared to developed countries.
Take care that humans evolving is completely different to advancements made in technology.
Last thing is, personally, I suspected that humans stopped evolving as soon as we grew a conscience!!!
As opposed to Natural Selection, could eugenics be the way of the future that our gene pool is manipulated. 'Artificial' mutations would be a way to remove harmful diseases and such, but I pretty sure the world is not ready for such wide spread uses...
Now, I hate to be all uppity, but eugenics is, what I think, completely and morally incorrect. Now, I think it's bad enough we research animals in this way, and we breed animals like this, but it's like saying: "Oh, you have desirable traits and so do I so let's produce offspring" Hell no! Also with "I don't have desirable traits, so I will continue to have no children or kill myself". But then again, I do see the point of it eliminating diseases, kind of like building a fence around a cliff rather than parking an ambulance at the bottom.
Hopefully, I could stop being such a cold fire, but when it comes to 'artificial' mutations, what do you mean by that? Gene Therapy? Search it up XD. Maybe it might make for a nice career choice; I am certainly keeping my options open!!!
Of course the human heigth is affected by genes, and on average, e.g. people in Japan have genes for shorther height than, say, Scandinavians. If an average Scandinavian person has a poor diet and health for much of his youth, he is likely to be about as short or maybe shorter than your average Japanese person. However, if the both have a good diet and no serious or long-lasting illnesses, the Scandinavian person is very likely to reach the maximum height that his genes allow, and be considerably taller than the Japanese person, whose maximum height is capped by his genes and does not increase no matter how much he eats.
As far as I know it is quite well supported that it was the environment, not genes that cause e.g. your average medieval European to be much shorther than what the Europeans are today. After all, human genes do not change that much in few hundreds of years. Even during the 19th century the average height was still much lower than today, so it seems quite certain that the genes for heigth haven't changed this drastically in less than 200 years.
The diet and health in general have changed drastically during this time, though.
In any case, if I'm correct, we might see something similar happening in the poorest regions of Africa today: if their health and diet increase during the next few decades, their average height should do so as well. I do not know if this has been observed or studied so far.
Last edited by biohazard on Mon Jul 05, 2010 10:38 am, edited 1 time in total.
I would like to point out that evolution does not have direction, and thus cannot go backwards. It is true that some traits can be reversed, for example bacteria easily lose their antibiotic resistance if there are no antibiotics in their environment any more. You could easily interpret this as goin backwards as the bacteria lose an ability and thus become less advanced and "poorer". However, what actually happens is that the new bcateria that do not have the resistance genes are actually better suited for their new environment and do better than the complex, antibiotic resistance ones because they do not carry the extra metabolic load of antibiotic resistance any more.
Similarly, albeit not as obviously, humans keep evolving even today. If poor eyesight can be fixed by spectacles, there is maybe no more need for good eyesight genes, and thus, in the current environment, humans could slowly evolve towards poorer sight. However, as the evolution only acts based on the current environment and the pressure it causes, this can be either bad or good in the long run. But evolution does not care about what happens in the future.
You also cannot count out technological advantages when it comes to evolution. Humans (and other animals) evolve to direction that allows them to best utilize their environment, and for us humans, the environment is a technology-filled one. Certain birds would starve to death if all sharp sticks disappeared, because they use sharp sticks to dig maggots to eat. They are evolutionarily bound to this "technology". Similarly, humans would do really badly in many areas of the world if there were no clothes. We have evolved to use clothes so well that we lost our own fur. Many crustaceans have lost their own shells because they use other dead animals' shells as their own and thus they do not need to spend energy to grow their own.
It is well possible that similar but way more sophisticated technological methods become integral for human life in the future. In history it was maybe clothes that was the technological innovation that allowed humans to conquer the whole planet. Maybe in teh future it is something high-tech stuff that must be implanted to all humans to allow space-faring. And without those implants, space-faring humans might risk extinction. Think about some method of eliminating solar radiation and cosmic rays, for example.
So, in a nutshell: humans keep evolving and evolution has no direction, nor does it aim to generate anything "good" - just gene complexes that do better in their current environment than their rivals do. (Or any other replicating entities. According to certain scientists, in addition to genes this could as well be any information, such as computer programs)
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