Is evolution going backwards?

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 country.

Could you perhaps substantiate that claim? Because a stressed population with completely undifferentiated mortality would be a completely novel situation in biology; and I have a hard time accepting that to be the case on just your say-so. See, I can think of a number of selective forces right off the bat:There's selection for body size, or for using scant caloric intake to the most effective degree possible. Because people are starving.There's selection for disease resistance, because people are dying from diseases.I think that you're conflating "fitness" as a biological term with "fitness" in its common parlance. This is an error. Biologically speaking, it doesn't matter how well you eat and how much time you spend in the gym; you'll never be as "fit" as the 300-pound woman in the trailer park, feeding Doritos to her nine children. It's entirely natural; conspecific competition is an entirely natural selective force. Please note that I don't mean "natural" as in "proper", I mean natural as in "not artifical." This is the same sort of competitive resource allocation that occurs in almost every species.And there's simply no escaping natural sexual selection.

Nicely put, and on a related, more pragmatic note, it's pretty well-established that the industrial nations have considerably reduced population growth, due to the avaliability of birth control. So biologically speaking wealth is generally maladaptive.

Ok, but that's a meaningless distinction in biology. The fitness or "quality" of an individual is based on the quantity of their reproductive success.I mean I guess I kind of lost sight of your point. Maybe what you're saying is that, in the West, we somehow concentrate our genetic "quality" into fewer individuals than they do in Africa, but in addition to the disturbing overtones of that statement, as far as I'm aware, pretty much all the beneficial human mutations that are currently spreading through the world's population are coming out of Africa. For instance, HbC.

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.

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."

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.

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.

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.

Evolution doesn't optimize; physical perfection is not likely to be an evolutionary outcome, no matter what environmental stress.It's like that old joke. I don't have to outrun the bear; I just have to outrun you. By definition, adaptations cannot threaten survival. Adaptations cannot be maladaptive. Only rarely is there a situation where there's even the possibility for positive selection for maladaptive traits; and there's considerable scientific debate over whether or not maladaption even actually occurs. There's always the possibility that a selected-for trait carries some benefit that we just don't percieve yet.

Uh, what are you talking about? Humans are not, largely, cannibals. We need resources that we cannot manufacture ourselves; we do not live by "self-predation."The word you're looking for is "competition", and yes, every species competes with its conspecifics for resources. Often that competition is lethal; most species (including our own) develop behaviors that allow individuals to compete for resources without killing each other. (Head-butting rams, etc.) That's the same game. Intraspecific competition. It's often lethal in species; it's often lethal in ours. It needn't always be lethal in species; it's often not lethal in ours. (When was the last time you had to kill someone to have sex? Come to think of it don't answer that.) It's not possible to exceed K exept over short periods of time. What has happened is that humans are able to modify their environments to increase the K value. The only upper limit I can think of for this is that humans need a certain value of calories to live, and the Earth only recieves a certain number of calories from the sun. Turning those solar calories into human calories is essentially an engineering problem. Equivocation on the term "fitness".

As I said, the word you're looking for is "competition." When a pack of hyenas chase a tiger from her kill, that's not expropriation or predation, that's competitive scavenging.Predation is a specific behavior that doesn't apply to where you're applying it. Humans do not, largely, hunt and kill each other as a food source. Again, we compete among our species, a nearly universal situation in biology. Which is exactly what I said happens in all species. Your point? To the degree that you have greater access to resources and mates, of course. Again, a nearly universal situation in biology and not anything special.

Still competition, as when a lion chases another weaker lion from its kill. I don't know how common it is for animals to actually predate and consume other members of their own species, although simply consuming bodies of their conspecifics isn't unknown, especially in the insect world.But for the large part, humans do not eat other humans. So I'm not quite sure how this example applies. The major human food source for all populations are other species - plant species like grains, or animal species. Human flesh is not a source of sustenance for any human population that I'm aware of; those few cannabalistic societies eat human flesh only ritually.On the other hand, the only competition we have for food sources are other humans, but this is not "self-predation", this is competition, which is universal in the biological world. I think that you're conflating these two points. One of what? Where species compete with other members of their own species for resources? Where a successful adaptation in one individual's gene line means the extinction or reduction of another's?You keep changing what you're asking for examples of, and changing what you think is so special about humans, so maybe if you clarify exactly what you're asking for an example of, I'll be able to provide you one. Now you've just lost me. You believe that human populations are shrinking, not growing? The word you're looking for to describe this situation is, as I've repeatedly said, "competition", not "predation." Let me see if I can spell it out for you. Predation is when you kill a cow and eat it. Competition is when you kill a man and eat his cow.

No, Contracycle, no. We only eat other species. We need resources like water, energy, minerals, etc. We don't get these from other humans. We get these from the environment, and we compete with other humans for them.It's amazing to me that this distinction is so totally lost on you. Predation specifically refers to the killing and eating of another organism. We predate cows. We don't predate other humans because we don't eat them! Look if you want to define words however you see fit, why should I bother? My patience is at an end with you because you refuse to use terms in the way that they've already been defined. That's every single species. Literally, every single one. That's how evolution works in a stable population - the more fit outcompete the less fit, and the gene lines of the less fit are extinguished. That's how mutations become fixed in a population - literally any stable population whatsoever. I don't know that evolution necessarily predicts that a population will increase in overall genetic diversity. Yes, it would. It's precisely accurate. Predation is the killing of another animal and eating it. Competition is the killing or rivalry of another animal for resources. Again, if you feel absolutely free to redefine the terms as you see fit, then I don't have time for this. But killing each other isn't the only way we allocate resources, though in our history it has played a large part. For instance, instead of killing the owner of the cow, I might become the leader of a government and simply tax cows. Or we might gamble for the cow, or engage in ritual, non-lethal combat. Or arm-wrestle. I absolutely disagree. Throughout human history the majority of resources have been allocated non-lethally, just like every other species. You're simply engaging in circular definitions - the only competition you find significant is the lethal competition; as a result you conclude that all significant human competition is lethal.

It's not a million miles away. But we have a word to describe the first situation - "predation" - and a word to describe the second - "competition."Why won't you use them? No, they're functionally different, because the people are not being eaten. Hence, this is competition, not predation. Again, these are specific words with specific meanings meanings that clearly perfectly apply to the situation, and it boggles the mind that you don't see it. But why on Earth would you bother? All it does is confuse the issue. God, why on Earth would you want to make things more confusing? What's wrong with you? Again with the confusing word redefinitions. I thought we were talking about evolution and biology, not Contracycle's Private Dictionary.But, in fact, these are not two differen things. Biologically both are simply a question of competing for resources. Mates are a resource. "Can I catch food"? is fundamentally the same question as "can I attract a mate?" There's only one question, and it's "what do I have to do to get the resources I need to continue my genetic line?" I'm not the one stubbornly insisting that his ideosyncratic nomenclature is superior to the terminology developed over 200 years of ecological research. You're an ideological slave to your idea that human society is so fundamentally worse than literally any animal organization; you're obsessed with the idea that humans suck so fucking bad that we have to pervert legitimate terminology to describe it. I've already engaged your point, and refuted it. The situation you describe is most analogous to interspecies competition, because that's exactly what it is. There's absolutely no need to make an analogy to predation because we already have a word for this exact situation.I'm at a loss, Contra. If you can't see the utility in the use of standard definitions for terminology, then there's simply no way to discuss with you.