Humans stop evolving?

[niviene]

Well, don't murder me for posting without being any sort of well-read informed person on the subject, but I did take a couple terms of genetic anthropology many years ago, and it has since been something I cannot stop thinking about. A couple posts have mentioned it, too. I do think we have really done a lot to remove natural selection from the picture. I am constantly trying to decide which side of that fence I am on. What happens when natural selection is removed from the equation? The gene pool begins to become more and more tainted with genese that should not have naturally been passed on, rather than dying off. For example, sickle cell. It's been so long that I may be thinking of the wrong disease, sorry. But, I thought this disease was supposed to be fatal in the childhood stages, and today people live long lives with it. Naturally that would weed out the carrier before he was able to reproduce, but now that is not the case. Am I happy that we now have the technology to allow these people to live such long lives?

 

The other side of that is that we have such advanced technology that our numbers are getting to be beyond the planet's capacity (well, perhaps not today, but when is that tipping point?). One part of me believes that natural selection should be allowed to run its course. Messing with nature scares me - a lot. Millions of years of nature, couple hundred of us. On the other hand, forgive a personal insertion, but when my daughter was born prematurely, I would have given anything for her to live, and the machines that attempted to do so were all we had to hope for - screw nature, I want my baby. I think it's hard to really choose a side without personally having to be faced with loss versus the technology to force a life to begin or continue. Unfortunately ours did not survive, but even after that experience, I still am sort of leaning towards nature. I feel that if I am struck by cancer or some other disease, or an accident which leaves me a vegetable, I would prefer to let nature take its course. My loved ones might not agree. I can't help but continue to return to this desire whenever I think about natural selection and evolution on the grand scale. Am I nuts? Can I be the only one? Of course, there's always the joke about removing warning labels from everything and letting natural selection work its course... perhaps a win-win? <evil niv>

[maikeru]

Well, don't murder me for posting without being any sort of well-read informed person on the subject, but I did take a couple terms of genetic anthropology many years ago, and it has since been something I cannot stop thinking about. A couple posts have mentioned it, too. I do think we have really done a lot to remove natural selection from the picture. I am constantly trying to decide which side of that fence I am on. What happens when natural selection is removed from the equation? The gene pool begins to become more and more tainted with genese that should not have naturally been passed on, rather than dying off. For example, sickle cell. It's been so long that I may be thinking of the wrong disease, sorry. But, I thought this disease was supposed to be fatal in the childhood stages, and today people live long lives with it. Naturally that would weed out the carrier before he was able to reproduce, but now that is not the case. Am I happy that we now have the technology to allow these people to live such long lives?

 

Positives and negatives and selection factors vary from place to place. One thing I like to keep in mind is that many groups of peoples, and thus many populations, are evolving and adapting to their locales past and present. And we have the potential to continue changing so long as the selection pressure is not 100% lethal (and prevents transmission of genetic material to the next generation) or as long as we don't become almost like clones (the sins of in-breeding or too much bottlenecking and limited genetic diversity).

 

In a way, I do agree that the number of selective factors has gone down. No longer do many peoples and populations need to worry about deadly diseases, drought or famine, deadly predators, or weather or climate that might have hindered or crippled us in the past. But I think new selective pressures have arisen or been amplified in scope and importance as societies have grown and become more complex. It seems that people are more selective about mates (such as requiring mates have similar jobs/occupations to them or similar education and looks, whereas in older days it may have been driven by social or familial pressures and traditions as well as necessity), and perhaps selective pressures that may have been driven by religion or tradition are increasingly less influential. I think interpersonal competitive and selective pressures are higher now than ever before, in a world dominated by money, and that shifts in culture and traditions also will drive changes in selective pressures and outcomes.

 

The other side of that is that we have such advanced technology that our numbers are getting to be beyond the planet's capacity (well, perhaps not today, but when is that tipping point?). One part of me believes that natural selection should be allowed to run its course. Messing with nature scares me - a lot. Millions of years of nature, couple hundred of us. On the other hand, forgive a personal insertion, but when my daughter was born prematurely, I would have given anything for her to live, and the machines that attempted to do so were all we had to hope for - screw nature, I want my baby. I think it's hard to really choose a side without personally having to be faced with loss versus the technology to force a life to begin or continue. Unfortunately ours did not survive, but even after that experience, I still am sort of leaning towards nature. I feel that if I am struck by cancer or some other disease, or an accident which leaves me a vegetable, I would prefer to let nature take its course. My loved ones might not agree. I can't help but continue to return to this desire whenever I think about natural selection and evolution on the grand scale. Am I nuts? Can I be the only one? Of course, there's always the joke about removing warning labels from everything and letting natural selection work its course... perhaps a win-win? <evil niv>

 

Carrying capacity can go up or down dramatically depending on natural resources, weather, land, etc. I'd say we're in overshoot. Unless we quickly learn how to tap into new cheap, sustainable, and clean energy reserves and recycle and restore resources, we will be living a world that has less of everything. There are always tipping points. Let the economic crisis be illustrative of that. I've noticed terrible degradation and disappearance of wildlife and heavy pollution problems now. I don't believe it needs to be an issue of "screw nature, I want my baby" if we don't make it that way. We do need to slow population growth, because nothing is infinite in a finite world. If we keep trying to view nature as something to be conquered, tamed, or exploited, it will always be humans vs. nature, rather than realizing we are a part and product of nature. Many cultures and groups of peoples learned to live sustainably and comfortably within their environments and locales for hundreds and thousands of years.

[HydrogenBond]

The brain/mind can adapt to changes quicker than biology. For example, if the earth started to get colder and colder, we could wait for natural selection to shift the population toward those with genes that are more conducive to the cold. Or we can use the brain/mind to invent clothing. The second scenario works quicker, does the same basic thing, and can trump this aspect of the natural selection process by changing the rules for selection. Now if anything, those whose genetics have naturally adapted to the cold, may place them in the wrong side of the energy balance, if no clothes becomes a taboo. Now natural selection would go to those who are warm enough with clothes on, but not too warm. Natural selection is still in play but the mind/brain changed the rules.

 

Sickness and/or resistance to sickness sets the rules for natural selection in animals. Humans have the mind/brain to invent science and fight disease. Natural selection is still in play, just the genetic shift for natural selection to certain diseases is more of a nonevent. The parameters for human natural selection changed, because we are using more people, than should have been still standing, under the old animal rules for natural selection.

[Vox]

 

Sickness and/or resistance to sickness sets the rules for natural selection in animals. Humans have the mind/brain to invent science and fight disease. Natural selection is still in play, just the genetic shift for natural selection to certain diseases is more of a nonevent. The parameters for human natural selection changed, because we are using more people, than should have been still standing, under the old animal rules for natural selection.

 

Personally I would say that the "single", biggest driving force to our "evolvement" and evolvement of "our" environment comes from our mind and key traits of ego.

 

Human Mind extraordinary capability to abstract thinking is the skill which will play key role concerning the future of the life in earth, all life form included or more or less life form which we have not been made obsolete up to date Abstract thinking can be seen as a blessing or threat to human race itself, depends how it is viewed or used. Mind can imagine concepts. "Subtle, delicate laws of the nature" etc and use this knowledge to modify heavily ourselves as living organism and the actual environment which we are living. Ego plays a role to enforce "I" as fundamentally important entity which should have something more than others around it, and views itself as "special" privileged being in the nature to mentally create abstract justifications of these privileges

 

From my perspective tracks leads to our left brain hemisphere, it seems to dominate within certain populations and cultures and is very efficient to impose "my own thoughts, concepts, huge complex systems/organizations and abstracts as a truth to its surroundings and environment. If our brains functioning would be more coherent concerning left and right brain hemispheres balance, things might look way different concerning the technical "development" compared to more holistic human approach and our effects /direct modifications to "our" environment. "Ego" concerns/owns earth as "my/ human environment" other species should give up and “step aside”. It (ego) forgets that it is the environment for all life forms in earth, but somehow we do not care and “I” comes first.

 

This egoistic approach would not do much harm if humans would not have this powerful abstract thinking and heavily favoring left brain trademark strengths of accumulating, analyzing detail knowledge, imposing questionable developments through powerful and complex societies and systems. For me it looks that humans and unconsciously developing as a sort of “cancer cell species” within all species, it (ego) refuses/resists to die, mind creates abstract concepts, theories an beliefs to support this view of not dying and uses it capabilities to survive and acts currently as a “cancer species” within earth. We cherish the Idea that we are passing "our" genes to next generation and ego get´s its illusion to live forever as specific entity which identity has been created in the mind itself and illusory targets of not dying.

 

We also might “succeed” and send colonies of other "cancer cell like human species" out to the space. We should remember not to go spreading to the space before we can sustain our own environment for us and other life forms on earth. My view is that we (especially me) as a species are not mature enough mentally to go and spread around the space in this current form. A recent development in earth itself is the biggest proof for this claim, at least for me. For some it might be proof of total opposite.

 

This way of thinking/writing might “raise many eyebrows” and create aggressive opposing views but I deliberately wanted to create blunt change of view/perspective from our “standard” view of “outside threats” to possible “inside threats”.

 

To put it bluntly; Human own actions in the current form of development is the most immediate threat to human survival or any other species survival in earth. Optimistic note; at the same time we are the ones who have the power and capability to change this direction of our own evolvement

[HydrogenBond]

Your overall message hits an important point. Humans can control their environment, thereby detaching the natural selection process of evolution from the natural environment. At that point, it is not exactly nature that is making these selections, it more like synthetic selection.

 

The reason controlling the environment is so important to humans is it prevents the wide swings in conditions that one might face in nature. These swings often thin the herd in favor of an advantage. Human sort of escape much of that. We can stay at a relatively constant temperature, in our homes, even when nature goes from 0F to 100F. We don't have to go from feast to famine, but can eat at any time. We are not restricted to what is available in our little section of the forest, but we can eat foods from all the over the world.

 

When we place animals in the zoo, we also alter their environment, which now includes a bunch of two legged critters who stare from the other side of the cage. Selective advantage is then defined by this environment with humans playing the role of mother nature, like they do with other humans. Being more sociable with humans and looking pretty can create selective advantage in this new environment, with show more often advantageous than go.

[Qfwfq]

I still am sort of leaning towards nature. I feel that if I am struck by cancer or some other disease, or an accident which leaves me a vegetable, I would prefer to let nature take its course.

I once got chatted up by a giraffe that was always grumbling about how its unnaturally long neck was interfering with the course of Nature, when instead it would be more correct to die of hunger when there's no foliage low enough to be reached naturally. When other herbivores beat you to it, let natural selection take its course. But of course, it ironically mused that, every time it's hungry, well, it just can't help saying "screw Nature" and going for the foliage it is able to reach.

 

I asked it why such qualms over so little. My homo habilis ancestors survived so unnaturally by crafting tools and artifacts and now that it's homo sapiens, building up more and more knowledge on which to survive ever less naturally, gee, I just told that giraffe to quit feeling guilty.

 

If medical treatment helps children with sickle cell anemia to survive and they are fine the rest of their life, well, it ain't such a great worry that they have offspring likely to inherit it. When it happens that treatment is unavailable to such children, that'll be a shame, but it isn't any worse than having deliberately denied it to avoid the next generation being born with it.

 

When Herbert Spencer coined the term "survival of the fittest" Darwin liked it and used it in his next editions of The Origin, but it met objections of circularity from the sharpest philosophers: Who are the fittest? How is this defined? The fittest are those that survive. Therefore Spencer's wording becomes "survival of those that survive"!!!! So it just underscored the fact that natural selection is inherently a matter of which environment a population is surviving in. If your environment is a society with a great medical science in which your hereditary illness can be overcome, it is no worse than the dodo having lost its wings.

 

P. S. If the baby was premature by non genetic causes then arguing for natural selection is even less called for, it's like feeling guilty for saving a baby that got bashed in a car accident or something.

Edited September 16, 2010 by Qfwfq
post scriptum