Evoloution and Humans: Does it stop?

the next big change, which is happening now, is that with so many advances in technology allowing people to live longer and have access to food and shelter and advanced healthcare combined with the fact that we are running out of natural resources.....well we just don't need as many people, so nature is producing more and more homosexuals so that we don't breed as much. Less breeding and less people combined with more knowledge and greater technology = a better life for one and all....so take that all you homophobes.....homosexuality....the next step in evolution.....

If nature needs fewer people, then why waste its time with homosexuality, why not go right to non-sexality? The next step in evolution... the housewife

one step at a time....the wheels of evolution turn slowly.....

Actually something along these lines was seriously proposed by anthropologist Marvin Harris. See his "America Now: The Anthropology of a Changing Culture" Simon & Schuster 1981.

Modes of natural selection currently operating:

Sexual selection. Many dumb ugly people still manage to procreate though, by pairing up. Likely we will get a very attractive segment of the population, and a vide variety of ugly people.

Self selection. Some have a stronger drive to procreate than others, and people in some lifesituations are more likely to reproduce than others. Also some choose to have more children than others. Thus we are selecting for people who get themselves into lifesituations which make them likely to produce offspring. We are also selecting for people who are likely to chose to reproduce (in any life situation), and people who reproduce 'accidentally' (thats right people, we are selecting for 'lifers' <shudder>).

In summary we are selecting for overly affectionate people who 'belive' they have 'found love' irrespective of sobering facts, we are selecting for people who 'adore children' and wishes to have as many as possible (and against those who would not procreate beyond their financial ability), and we are selecting for promiscuous anti abortionists who can't be bothered to use protection.

In addition random mutations which are no longer selected against will become more and more common, reducing resistance to desiese among other things.

I'm not optimistic

naturally I knew that...and you guys think I'm just a rocker burn out clown :wink:

Well, it still builds on a misunderstanding of the theory of evolution, but I'm sure you knew that too.

actually I don't know jack ****...I'm just a burnt out rocker/clown...

Good stuff, ros.

Neil,
Have you considered the survival rate to reproducing age in the equasion? I don't have any way to figure that aspect currently but I suspact that it would have some bearing on reverse evolution.
Another aspect is life expectancies.
Still another is the fact that western, Indian (which has suddenly become western), East Asian (ditto) societies, have historically had no trouble supplanting primitive societies when the fancy took them.
Unless we bomb "ourselves" back into the stone age I suspect that selection for intelligence (of a sort) will continue to be selected for. This will probably continue as long as we inhabit this type of body that is ill suited for any specialized task except the one of carrying a brain around!

Given the size of our current population and the amount of genetic mixing that is occuring as a result of modern transportation systems, natural selection is not a very strong force on the human genome. There just isn't enough isolation among groups for speciation to occur, and any major changes that do occure are going to get "drownd out" by the huge number of people in the world.

It is true that modern medicine has allowed for the continued servival of "unfit" genetic material, but again, this is such a small percentage of the gene pool, and the gene pool is so huge, that it just doesn't matter.

There are two future events that can (and almost certainly will) bring evolution back into play with the human genome:

1) A "bottleneck" in our genetic history. This basically means a dramatic decrease in the number of people in the world. It may be that some global cataclism will kill off vast numbers of people, resulting in "fitness" becoming an issue again, or it may be that some system of social controll for reproduction will take place and remain in place for several mellenia. Either way, we would see a "culling" of certain genetic strains of human bengs. Of the two I would bet of the global catastrophy as the more likely - human beings just arn't that disciplined. Note that what we consider "fit" may not be what is selected for by this process. There is no real reason why intellegence (for example) will be advantageous in the "bottleneck" phase our development - maybe fecundity or small stature will be selected for.

2) Unnatural selection. Here I am refering not to preferential breading patterns (like selecting for tallness), but rather actual direct manipulation of the genetic code. This is huge. Consider modern genetic manipulation is nothing less than genetic material, getting up, walking around and making decisions about how it wants to manipulate other genetic material! This kind of positive feedback loop is the biggest revolution in evolution since the invention of sexual reproduction. Frankly, the modern human has become obsolete, we just haven't realized it yet. Genetic science is going to allow the direct selection of specific traits, and eventually the custom designing of new traits in the genome of all maner of creatures, human beings included. Is this a frankenstein monster? Almost certainly. Can we put that genie back in it's bottle? Nope Im afraid not.

So, IMO evolution is about to go into overdrive because of these two factors. Hope that brightens your day! :wink:

I agree (and have stated the same in other threads). Assuming our own actions don't hinder our progress, natural selection is about to feed back on itself through intelligent genetic intervention.

Wabbit, you have provided a fascinating look into current scientific understanding of evolution! I read through the article several times as my poor old brain needed much repetition to let the ideas and new concepts including the amazing specialty areas of science sink into something as a cogent whole to my understanding of evolution. Thank you very much!

I've been interested in the current problems over evolution, with the folks that are forcing "Intelligent Design" to be substituted for or at least taught with equal time in science classes in public schools of the US. The creationists that are latching on to ID as the way to discredit all of evolutionary theory are succeeding in the US with alarming and increasing success. Local school boards are being forced to have teachers "teach" that evolution is "only a theory" (well, doh!) and therefore may not be important important precept for science education. And they introduce ID as also a "theory", which they insist is taught on equal standing to evolution.

As our mutual friend Armadillo says, evolution and sciences deals with the "how" of things and philosophy and religion SEPARATELY from science deals with the "why". It's hard to imagine a greater challenge to continuing science education and study than the current debates. I am very glad to see by the article, that there are vast differences of opinion held by European and other nations. Right now, the US is seeming to be more parochial and less and less "advanced" than our government would like to believe.

Not so much evolution as breeding
I doubt humans will change much due to natural selection. Medical science now allows just about everyone to pass along their seed. Large headed babies who once died in childbirth can now be born via c-section, so I guess that is one trait that can now prosper.

Breeding for traits is another matter. In many parts of the world, smart people are now meeting in school and intermarrying. The controversial book "The Bell Curve" presented some evidence that intelligence is hereditary and suggested that this will result in median intelligence dropping while an elite upper minority forms. Of course, reproduction rate is inversely proportional to education, so smart folks might breed themselves out of existance. While short and tall, skinny and fat people all get to pass on their genes, they seem to migrate to like souls, so the extremes will increase. Also, existing differences between sub groups of humans will be erased as intermarriage between geographically different groups increases.

Engineer,

I suspect that when "push" comes to "shove" intelligence will be a survival tactic. And it'll be rough on everybody. War often is except for the ones that are intelligent enough to stay out of it.

Canine evolution (breeding) might be a good model for what we can expect in human evolution since many of the same forces (human intervention and selection) bear on the populations.

Over the last fifteen thousand years, canine breeding has forced changes in the distribution of alleles in the gene pool. We don't exert quite the same level of forced breeding on ourselves, but we will probably begin selecting and inducing allele frequency changes more and more as genetic technology improves.

All dogs are of the same species, even wolves. In fifteen thousand years of aggressive control (artificial selection), we still have not created a new species, only new breeds. However, in the last two hundred years, our technology has advanced from horse carts to genetically modified plants. Which is more likely in the next thousand years, a new species of human due to natural selection, or something new due to manual manipulation?

People are viewing all these scientfic advances as if they are making life better for people on earth. I have always believed that quality is better than quantity. Sure these advances in science may allow you to live for 200 years, but everyone will be living that long. How enjoyable will life be when you are sharing the Earth with 40 billion other people? How about food? Taking pills instead of food. That will make for some interesting thanksgivings. Next time you begin to fantasize about how wonderful the world will be in the future... look around and realize that the quality of life will never again be as good as it is right now.

A note on stem cell research. I am a Californian and two weeks ago we passed a 3 billion dollar bond proposition to fund stem cell laboratories, in the midst of a 20 billion dollar state deficit. That tells me alot about where people's priorities are. While families are starving and elementary schools are closing, three billion dollars is being spent on unproven technology with hopes of curing diseases and prolonging lives. I think it is quite selfish creating medical treatments that allow the wealthy to live longer while the lower class struggles to survive.

krekmoney,

Thanks for seconding my observations

Intelligence is indeed a survival tactic for the human genome

Scientific advances bad??


I think you are missing the point. Science is science and can be used anyway we want. You made a comment in an earlier post that arts, music, etc are what make us human. I think what makes us human is contained in our genetic code. What we choose to do with our humanity is a different matter.

Has science made life better for people on earth? Sure. Seen a smallpox or polio victim recently? People were so scared of polio that they wouldn't swim in the summer. These illnesses not only reaped a physical cost, but an enormous mental cost in terms of fear and isolation. Can stem cell research produce equal advances? I don't know, but I applaud California for taking up the gauntlet that the federal government dropped.

That's because they are making things better.

You don't like indoor plumbing? Electricity? TV, Telephones, Cars? Do you prefer tooth decay, and dentistry without novacaine? Summers without air conditioning, food storage without ice? You prefer the cities of the middle ages ravaged by plague and disease? Or you prefer huddling in caves wrapped in animal skins fighting for a place around the fire?

The world certainly isn't a perfect place, and it never will be, and sure, scientific advances can be misused, but over all, I think we're a whole lot better of now than we ever were before, and I see no reason to think that the way we have it now is the best it's ever going to be.