Is evolution going backwards?

Lethal recessives meet all the time in the human population, what's that if not natural selection? Almost any karyotype change is lethal to highly deleterious.Mark

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There are 10 kinds of people in this world; those that understand binary, & those that don't

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Lethal recessives meet all the time in the human population, what's that if not natural selection? Almost any karyotype change is lethal to highly deleterious.

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As I said I don't dispute the mechanisms are still present. I merely think they have been puched back into statisticial insignificance by comparison to the effects of human action.Most organisms compete against other, different organisms. Cheetahs and leopards compete for game animals, so one can see that an increase in some fitness that contributed to hunting prowess for an individual leapord may improve the individuals survivability, hence reproductive opportunities, hence impact the species of leopards as a whole in their competition with cheetahs.We compete against each other to a massively disproportionate degree by comparison to competing against other organisms. An increase in the fitness of one person may improve that persons survivability (although I contest this is important above) but in so doing it may also massively decrease the survivability of other members of HomSap.So it seems to me that now, becuase we control our environment to such a tremendous degree, and our competition and predation is almost entirely intraspecies, we are playing a kinda evolutionary zero sum game in which any positive mutation which arises may well only have the effect of wiping out many other positive changes that had arisen in the population.In most organisms, the down side to the increased effectiveness of an organism is externalised to another prey organism. In humans, the down side is suffered by us, becuase we are our own prey.

At the risk of actually agreeing with you on something , I find that this statement: is one with which I totally agree. Cultural evolution in humans has trumped biological evolution. I'd say this is manifest in everything from our impact on the global environment to the effects of resource exploitation, etc, on other human populations. Culture operates at a speed several orders of magnitude faster than biological evolution. Whereas there may be some instances of genetic change due to the "old way" (natural selection), the most important factors/changes in our species at least since the invention of agriculture have been cultural and technological.Of course, I don't agree with your depiction of this as class warfare, but we agree on the gist, IMO.

And what I'm telling you is that people in the undeveloped world are still having more grandchildren than you and I, so this "quality" strategy clearly isn't as effective as the "quantity" strategy.It isn't better at bringing children to maturity, because the undeveloped world is still bringing far more children to maturity. Biologically speaking it's obvious that the quantity strategy is far more successful than the quality strategy.

I didn’t say ‘Quality’ was overall better than ‘Quantity’. What I said it was better at bringing EACH child to maturity, where as ‘Quantity’ plans for and builds in protection against a far higher rate of attrition. And here’s where a high quality of life (comparatively) ‘wins’ as a strategy, not against other solutions but, in and of itself as a method of sustaining the species, within available recourses. Sure the ‘Quantity’ solution produces more individuals but those populations are also prone to devastating culls through natural disasters such as floods and drought, not to mention man made disasters like wars, then it needs to over produce to survive these periodic culls in numbers.It’s not a question of one being better than the other but what is right for the socio-environmental situation in each area. So saying wealth is mal-productive in regard to survival of the species is in error as if our growth was not checked by birth control and a change in the social norms (i.e. smaller families) brought about through wealth and technology, then we would grow to truly unsustainable numbers exhausting our recourses even quicker than we are. And species that eats itself out of house and home does not survive.If the wealthy nations of the world actually got off their asses and put in good water, sanitation and power infrastructure into all the ‘undeveloped’ nations who have historically leant to the ‘Quantity’ strategy to perpetuate their numbers they would have to also adapt a more ‘Quality’ outlook or face a population explosion of frightening and unsustainable proportions. Both strategies are valid and of themselves ‘win’, but only for the situations that gave rise to them.

basically what you are saying is that our fitness mechanism has been externalized (medicines tehchnology etc) so that it is available to {those that can get it} regardless of genes.

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we are limited in our ability to understand
by our ability to understand RebelAAmerican.Zen[Deist
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Swell.That's completely irrelevant to considerations of biological fitness. Well, no, it does - it survives at the K value. (Actually it occilates around the K value, but doesn't depart significantly from it.) It's highly rare - possibly unheard of - for a population to grow itself into extinction, because the massive die-offs as the population exceeds K reduce resource use, until the population reaches K equilibrium. You're speaking in entirely subjective terms about what is "best." The point I've been making the whole time is that that's a different question than what is most "fit."

but as has been pointed out, (and lord help me for agreeing with Contra here) that due to our tecnology, and wealth, survival is no loger purely a question of biological fitness, at least for the human spieces.But I am probably arguing at cross points here as I obviously dont have a fully scientific grasp of biological fitness in the terms you are useing it. I would greatly aprecieate if you could point me in the directions of apropriate online texts or even apropriate books.yours Ohnhai

To the degree that behavior is not genetic, perhaps. Survival or extinction of the human species may be cultural/behavioral at this point. But then, maybe not. Diseases will always adapt ahead of our ability to respond to them; when the superbug hits survival is going to pretty much depend on mutation. It's not a complicated concept. It's simply about how your genes spread through the gene pool; for that to happen, your offspring have to constitute an increasing fraction of their population. (This is why all human ancestry can be connected back to one human woman, even though the human population has never been as low as one or two humans.) So biological fitness is pretty much just a function of how many grandchildren you have, if you will.There's no way to speak of the fitness of an organism except in regards to how its genes either spread or contract in the gene pool. Anything else is entirely subjective.

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To the degree that behavior is not genetic, perhaps. Survival or extinction of the human species may be cultural/behavioral at this point. But then, maybe not. Diseases will always adapt ahead of our ability to respond to them; when the superbug hits survival is going to pretty much depend on mutation.

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I would suggest that most of our development and survivability is now located in our knowledge, rather than our physical bodies. That I think is a major difference to how the physical world impinges on our fitness.

This isn't really the case, except in the specific case of a growing population.Eventually all populations reach K, or the carrying capacity of their environment, where they stop growing. At that point more for me does mean less for you; that's true if we're humans, cheetas, or what-have-you.Stable populations of any species are zero-sum games, just as you described for humans.

since, that the 'survival of the fittest' is no longer taking an effect.How do you figure? Most of the world doesn't get enough to eat, or have adequate housing. For instance, the life expectancy of a person living in most of Africa is under 55 years. Sounds like negative selection is very much in play for the human population.And that doesn't even get into sexual selection, which you can't get rid of. You know, unless all human beings learn to reproduce asexually.Natural selection is very much still at work on the human species. Even in this countryWait a second. Due to organized civilization, evolution in human beings can't happen anyway. Evolution is about new species winning in competetion with old species. Do you think that in cities, where people have little to no threat of being killed, starved, or preyed on, people can evolve? If Steve's nephew is stronger, and faster than Steve, does that mean that Steve won't get to eat as much at Thanksgiving and will die? No! If someone is fat and slow in our country, they can still get a big juicy steak at the store as easy as a big strong person. Physical developement does not play a part in Human Survival! Even if a fat person has a heart attack, he can be saved by the red cross and live to have children who will also be fat. So now I would say that even if there was evolution, it would be going backwards due to society. In a few decades everyone could be fat! Physical developement just simply isn't an advantage for humans. And according to the theory of evolution, useless characteristics of creatures would be evolved away after a while, so in a few thousand years, according to evolution, everyone just might be fat after all! I can't wait! Everyone will say, "hey chubby!", or, "Good Morning , Fatsoe!"
Seriously, modern society would cause evolution to move backwards, and that's because physical development would not be an advantage anymore.This message has been edited by LDSdude, 01-20-2005 21:04 AM

Sexual selection always occurs in sexual species. So that at least is happening, and that's evolution. No, evolution is about changes in the allele frequency of a population that are non-random. The way we live, and where we live, is driving those changes, so evolution is occuring in the human species. Any time people reproduce at different rates, or some reproduce and others do not, and it's not at random, you're going to have evolution. You need to break out of this competitive life-and-death-struggle model you have in your head. That's not the only way evolution occurs. If they're too fat to get laid, or they have a coronary and die without reproducing, then evolution is occuring. Or if the alternative occurs, and the fat guys get more chicks and have more kids, evolution is still occuring. The only way for evolution to go "backwards" would be for time to go backwards. Evolution goes forwards, always. The selection pressures change, but selection still occurs.Allele frequencies in human populations are changing; it's measureable and non-random. Evolution is happening in the human species; it no more goes backwards than time goes backwards.

You need to understand what you are talking about before you make too many wild statements.Evolution doesn't have a direction so it doesn't have a forward and backward. It could be that the enviroment selects for bigger and stronger at one time and smaller at another. It is all just what best suits the environment of the time.Humans, in some societies, may not be subject to the same selective pressures as wild humans were. However, that does not mean that we are not subject to any selective pressures.For example, humans decended from Europeans who went through the black death have different genetic features than others. This is an environmental selection that has made a change in the genetic makeup of a population.We are still evolving. We just don't know in what way.

If evolution were going backwards it would be called "Retrolution." Duh.Was I supposed to contribute something meaningful...oops.
Brad