Debatable. There is a view, as Paleo mentioned, that our adaptation is now wholly social and technological. But one looks a events like the massive AIDS epidemic in Africa and it will be interesting to see if natural selection begins to favour those with improved immunity to that family of retro-viruses.

This is probably way off, but since we apparently have some pretty smart people on this thread, I figured it was a good time to ask.
I have wondered about certain things we do and how it'll effect us years and years from now. A good example of that is bottle feeding children. If the majority of women continue to not use the breast for feeding, would that mean that one day we'd stop having breasts? I have a few other things like that I wonder about, and I'm sure this sounds idiotic, but well, they say no question is a stupid one.

I sure hope not

Have no fear-as far as I know the breasts are here to stay whether we bottle feed or not.

Yes, we are. Evolution is a natural process-it doesn't just stop. There is no acme or apex to evolution.

Evolution is the process of an organism adapting to an enviroment. Humans control the enviroment, hence no pressure to change.
Modern medicine has allowed people with impaired immune systems to live and pass on their genes. This is not evolution as I understand it.
Did we evolve to be resistant to polio, TB, smallpox or flu. No, we made medical and cultural changes to beat them.
Steve

I think the REAL change has only taken place in the last 100 years. Carbs are probably ok as long as you're physically active all day long. They're getting used as fuel. I think the change has been in the last few years where everyone's activity level has dropped tremendously at the same time sugar and refined carb levels and calories in general has increased.

So maybe in a few thousand years from now, we'll adapt to a hummingbird's diet (sugar water ) but in the meanwhile, those of us who aren't adapting are going to die off.

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This is not exactly correct. Ecosystems evolve, not individual species. The environment is not simply a background for a species. For instance, we can track the changes from eohippus to modern horse, but the fact is that the horse evolved along with the evolution of grasses and the development of grasslands. These are not just parallel developments, but part of a unitary change.

The same is true for human beings. The ecosystem in which humans are a part has not evolved significantly since the advent of agriculture 10,000 years ago. That ecosystem has deteriorated, but we should not mistake that deterioration for evolution. The northern Sahara has been turned into a desert because of deforestation caused by human population pressures, but the relationship of the human species to forests has not changed.

The evidence is that paleolithic human beings were larger, longer-lived, and had greater bone density than current humans. The likelihood is that the switch to a carbohydrate-based diet from a protein-fat-based diet that occurred 10,000 years ago caused a switch in the species' strategy to protect its gene pool. Whereas previously, the abundance of preferred nutrients allowed a strategy of fewer, long-lived, large individuals, the decline in preferred nutrients changed the strategy to protect the gene pool to more individuals who were smaller and shorter-lived; hence our current disease-ridden overpopulation.

Hello
An individual species can evolve within an unchanging ecosystem. If the evolutionary changes make the individual more successful within that eco system.
Steve

All evolution is, is the change in gene (or really allele) frequency within a population or species. Are you really saying that there has been no gene frequency changes in humans?

Humans do not completely control the environment. While, I agree that modern medicine has allowed people that would have been selected out of the gene pool to survive-the vaccines and antibiotics developed by modern science are not completely successful. Whooping cough for example, is on it's way back-people still die of the flu....viruses and bacteria co-evolve with us.


Individual species do evolve. I don't know where you are getting your information, but that is pretty basic.

There is no evidence, as far as I know, that paleolithic humans were longer lived, either. Neandertals (and paleolithic moderns) were larger in muscle size and bone density, but not height. Because they used their muscles in highly strenous activities that leads to larger muscles which in turn makes bones more dense. It was due to activity levels, not genetics.

I think you might be slightly confused. 2 things are wrong with these stements.

First, you assume that we, humans, control the environment. We very much do not. We can control some of our responses to the environment, and also shelter ourselves from some of the dangers to the environment, but we cannot control the weather, animal behavior, earthquakes or volcanic activity, or many other things that constitute environment.

Second, you assume that in order to evolve, we must IMPROVE. This is also not true. As others have stated, evolution is referring to genetic change in a species over time and multiple generations. This is not a positive or negative. Natural selection has always implied a positive change in genetics, i.e. an increase in survival. This, NATURAL SELECTION, is what we as humans have changed by our technological advances. Because we can improve the lives and reproductive ability of those who would normally not have survived, we have REDUCED the outside force that natural selection puts on our species. We have NOT eliminated it, as the examples given above such as HIV and retroviral infection in South Africa have so nicely pointed out, but we have reduced it.

What does this mean? Some of our evolutionary progress might be marred by this loss of natural selection, but it also means that we are selecting for our society, and we are making evolutionary progress there. We are beginning to act more as a clonal society rather than individuals in regards to natural selection, which is a whole other topic. Obviously, if we were all actual clones, then we would not be evolving any more, but as a society, we are working to improve the ability of even the weakest to survive, smart/resourceful people are saving the lives of weak/sickly people, and this has no genetic/reproductive benefit to the smart/resourceful people (unless they get money, which they sometimes do). This is unique to us as humans and is, as far as I have always believed, part of what gives us consciousness, or humanity. On the other hand, it reduces the effects of natural selection.

Of course, none of this takes into account the choosing of mates, which we are also doing "incorrectly" for traditional natural selection by choosing the wealthy, intelligent types rather than the strong healthy types (on occasion). Basically, our definition of fittest has changed from what nature dictates it should be. Is that so wrong? Probably not. Either way, we are still evolving, just not necessarily the same way that animals and trees do anymore.

Never a stpid question if it is well thought out...

First off, I don't think that the MAJORITY of women are not breast feeding, or at least I hope it isn't a marjority. From what I understand, given the health implications, the only place women are encouraged to NOT breast feed is in South Africa if the mother is HIV+ and they're hoping the child won't have gotten infected during gestation.

Second, NOT breast-feeding seems to increase the instance of illness in the first few months because breast milk has protective immunological effects. I would say then, that if we were to logic it out, that any woman who does breast feed should have healthier kids, and these kids would be more likely to breast feed because their mother did, and their kids would then be healthier, . . . Basically, I would guess that even as a minority, breast feeding would happen often enough, with the improved health advantage to increase reproductive capacity per generation, that it would be able to mix throughout the population and keep breast from dissappearing. ALL SPECULATION OF COURSE.

Third, the issue of breasts has become more than just for feeding babies. Breasts are used as a measure of women in choosing a mate, so even if they became useless for feeding (i.e. if lactation went away through evolution), the breasts would likely remain and become more like a human equivalent of a peacock's bright colors (although isn't that the male?)...

I tried to look up some statistics. About 59% of American women breastfeed. Then about 11% of those drop out after 7 days. Then the most dramatic decline occurs around the 2-3 month mark, About 29% more stop at that point, and mostly due to having to go back to the workplace.
Eh..well, you know statistics, it seems generally accurate, according to my family and friends that I know about. That's quite a lot of women if you ask that don't breastfeed, but I guess that's where you're point comes in that its still enough to not change us.
I realize the health benefits of breastfeeding, and think most women do too. Just one of those "yea nice information, thanks for sharing but I would rather bottle feed." At least that's the response I recieved from those I encouraged.
As for the attraction, I understood that by nature men are attracted to breast and hips, due to the underlying, fundumental urge to pick the best mate for well..makin babies. thanks for the answer, interesting side-track off topic we have here.

thanks for the statistics info. it does sort of puzzle me when I hear from people who know it is healthier and still choose to bottle feed instead.

Anecdotally, my sister-in-law adamantly refused to breast-feed, and her 4 mo old baby has been pretty much chronically sick with a cough and sniffle for the last 3 mo, and yet she doesn't think the lack of breast-feeding has anything to do with it. Also, she's constantly worried about "exposure to germs" and avoids bringing the baby out in public or let people hold her. She was like that before the baby came, so it's not that she's reacting to the baby being sick. Maybe she's hoping the two things will balance out? Not sure that's even close to a fair trade-off.

Actually, I read somewhere that raising a baby in too sterile an enviroment can increase their chances of developing asthma because their immune system does not get built up as much early on (by exposure to some germs). Strangly enough, when I was a baby my parents would not let anyone near me for the first few months and they wore surgical masks when they were near me (sounds terrible but my mom lost a baby to SIDS before me and was originally told it was a viral infection). And I had terrible asthma as a baby and child . . .

-J