Are humans still evolving?

Mentock, what I didn’t say is that the article is approx. 17 columns long (remember that The New Yorker runs 3 columns per page) so I was reluctant to sumarize it. I’ll try but won’t begin to do it justice.

Reputations
THE ACCIDENTAL CREATIONIST
Why Stephen Jay Gould is bad for evolution
by Robert Wright

For general flavor it starts with:

“Four months ago, when the Kansas Board of Education voted to cut evolution from the mandatory science curriculum, few people were more outraged than Stephen Jay Gould.”

And then goes on to say that Gould has unintentionally given real strength to the creationist movement…He is “giving non-biologists a largely false picture of the state of evolutionary theory.”

He’s done this over the past three decades by stressing the “flukier aspects–freak enviornmental castrophies and the like–and downplays natural selection’s power to design complex life forms.”

(Gives a couple of examples)

Gould and the creationists “both for their own philosophical reasons want to depict the evolution of a human level of intelligence as spectacularly unlikely.”

And then on to Social Darwinism. Directional evolution and/or progressionalism (evolution goes to the more complex by its nature rather than other mechanisms like positive feed back) "was dear to the hearts of social Darwinists, who used evolution to justify racism, imperialism, and a laissez-faire indifference to poverty…

While social Darwinism is long dead, for Gould it is still an enemy.

He champions “punctuated equilibrium” the idea that evolution moves in fits and starts, something considered by Darwin but bills them as if “fresh and radical” another idea embrased by creationism. He also called the Darwinian theory “effectively dead despite its persistence as textbook orthodoxy” and while he has since qualified this claim the sound bite is used over and over by creationists.

More examples of things Gould has written which are either not correct or fuel to creationists.

Leaves Gould for nearly all the remainder of the article and give several examples of how evolution does work.


Are you driving with your eyes open or are you using The Force? - A. Foley

Thanks! Jois

And for the personal fairuse email, service above and beyond. I’ll make a point of digging up that New Yorker article, just for that. I am a fan of Gould, but he do make me crazy sometimes.

At the risk of being told on again, I still want to make the point that it’s “social darwinism” that seems to be lambasted, not the doctrine of “survival of the fittest.” No one seems to have said that they are equivalent–except maybe social darwinists.


rocks

Are there not small, yet noticable, changes happening over a short period of time?

For example: people today are taller then those of the past. If you visit a castle, even built less than 1000 years ago, you will notice lower doorways and shorter beds (although it could be argued that this was because people sat up in bed for quick escape in the event of attack; but surely not all night). I’m sure that people are also taller from generation to generation, a far shorter period of time.

Also (it might just be me noticing this), the feet of my generation appear to be larger than the average feet of my parents generation. This may sound stupid, but I have often heard older people remark about the size of feet of the younger generation. If this is really the case, I wish footwear manufacturers would notice so that I will have less trouble finding shoes that fit.

These changes may not be greatly significant, or appear as obvious physical changes, but they are likely to be owing to evolution. However, it sounds unlikely that in the future, the average person will be seven feet tall. But it might just be the case.

This has been noticed, but it’s believed to be the result of better diet, which is because of better farming techniques resulting in more available food. A lack of vitamins and minerals in the diet will stunt children’s growth and development.

Back in 1915, director D. W. Griffith made a movie about the Civil War and Reconstruction, entitled Birth of a Nation. (It also made the evil KKK seem like the good guys, but that’s irrelevant to this discussion.) Anyway, Griffith wanted his film to be as realistic as possible and he got the idea that his actors would wear authentic Union and Rebel uniforms rather than copies made by the costume department.

But he ran into a little snag: What uniforms he could find that were still in wearable condition were far too small for any of his cast. (Part of that is because some Civil War soldiers were very young, no more than 16.) Because of superior diet and, frankly, an easier life, people had gotten much larger in just 50 years. And Griffith ended up having to use copies after all.

Welcome to The Straight Dope.

Katt mentioned technological adaptations leading to diminishment of evolution in our species - yes. Certainly this could be true, or even, certainly this must be true.

But how drastic would an adaptation have to be for us to notice it anyway? We move all over the USA and keep on exchanging genes so even if an excellent possible genetic change popped up wouldn’t it take thousands of years to get into our whole population?

We no longer have room in our jaws for all our teeth, the “wisdom” teeth have to be removed due to lack of room. I think we talked about this somewhere else in this board about how some groups on Europe are born with only 2 or 3 of these extra teeth.

Think of how long it would take for this gene to spread - it is like blood type - you can’t see it from the outside so it is not sexually selected, pure randomness. Back to Katt again, we use surgery and antiobiotics to “fix” this problem.

In the olden days the person with 4 wisdom teeth might end up with fatal infections of the gum - with the wisdoms growing in sideways, for example. It might have removed many people from the gene pool since wisdom teeth grow in during the reproductive stage.

Jab1 got it right on the nose with the improved diet making the changes in our height and even feet. 1950 might be the cut off for nutrition and full potential growth.

I think 5"11" average height for men hasn’t changed since that time (was 5’10") and women’s average height was 5’4" for years and then changed and has now remained at 5’5" -IIRC since 1950.

Remember good old Cro Magnon? he was 6" tall, so in the long long run, we are getting shorter!

Maybe this would be a good question for “General Questions.”

Are you driving with your eyes open or are you using The Force? - A. Foley

People tend to think of evolution merely in terms of adaptation, adaptation in terms of natural selection, and natural selection primarily in terms of physical traits. Of these, only the second is really quite the case. (Cecil’s answer was pretty much along these lines, which is why I found it objectionable).

The fact is, the selective pressures imposed on our species by the physical environemnt have largely been obviated by culture (technology) (but not entirely), but our social environment also imposes selective pressures, and that has been changing extraordinarily rapidly. Evolutionary psychologists, sociobiologists and the like interpret our thinking and behavior in terms of our evolutionary past, and recognize that our psychology is filled with traits that were supposedly adaptive in the midst of the social and physical selective pressures of long ago. As this “evolutionary landscape” changes, it is inevitable that behaviors, thought processes, etc. that are maladpative will be selected against, and other traits will be selcted for. So our species will undoubtedly continue to adapt to changing conditions, or else face extinction, which is also part of the evolutionary process.

Getting back to it Mentock, let me be unequivocable and explicit. If you doubt me, you can look it up yourself. The term “Survival of the fittest” was penned by Herbert Spencer, Not Charles Darwin. Herbert Spencer was the founder of so-called 'Social Darwinism." Social Darwinism was NOT Darwinist, it merely used his name, just as Creation Science isn’t scientific, it simply uses the name. Spencer used the term “Survival of the fittest” to describe Darwin’s notion of Natural Selection. The problem was, “Survival of the fittest” (or, “only the strong survive”) is NOT what Darwin was saying. Nevertheless, the phrase causght on, and now when people here 'Survival of the fittest" they think of Natural selection, and vice versa. Some evolutionists still use the term for two reasons 1) they honestly don’t know any better or 2) They know better, but it’s simply convenient, especially since it’s so engrained in the popular consciousness. Others try to set the record straight. If you know anything about Darwinian theory, you can see plainly that the phrase does not accurately convey the essence of Natural selection. If you know anything about the history of the term, you are outraged that it is still in use. If you know anything about the current socio-political climate, you also know that social Darwinism, fascism, racism and eugenics are not only still around, but they are becoming increasingly visable. Just as griffith’s 'Birth of a nation" lent an air of legitimacy to the Klan and essentially resurrected a dead entity (The Klan was defunct for years until after the movie came out) to lend legitimacy to Spencer, his ideas, or the vestiges thereof, cannot be a good thing. And, again, it simply isn’t Darwinian.

I don’t really doubt it, but I have tried to look it up myself. I long ago stopped trusting my gut reaction when I disagree with the Straight Dope and I try to look it up before I spew. I’ve pursued all the citations in this thread, and read all the quotations. None seem to support it. I’m still looking–but I did raise a skeptical eyebrow when your claim that it appears in all the intro biology books turned out to not be true of the two college biology books that I was able to get my hands on.

Why do you insist on holding the Straight Dope feet to the fire, when it appears that the SD opinion could have been based upon legitimate texts–regardless of their rightness or wrongness?


rocks

Good thread! Getting back to the eyeglass thing-surely myopia is not a good thing for a hunter-gatherer society. If it is genetically determined, why is it still with us (40% of americans are myopic)? How about skin coloration-darker skins are obviously an adaptation to stronger sunlight-how long before the european immigrants in Australia start sporting natural tans?

Hi EGKelly, This is a good thought:“Good thread! Getting back to the eyeglass thing-surely myopia is not a good thing for a hunter-gatherer society. If it is genetically
determined, why is it still with us (40% of americans are myopic)?”

I’ve been reading about hunter gatherer groups and they are noted for their huntin skills, silent and deadly. They rely now and did rely ages ago on being kinda close up and personal. Imagine getting an elephant with a spear? Have to be a lot closer (a whole lot closer) than I’d like to be do to that. And they didn’t use the little “L” shaped things that increased the power of the user.
The elephant hunting/killing story I read said that the pygmy stood in front of the elephant while it was moving to make the kill.

So between the tools used, the animals hunted and the hunters - they probably got pretty close up and they frequently hunted in groups. Several hunters in a semi-circle closing in towards the middle - seems like they wouldn’t need much in the way of power vision to kill with an ax or spear.

EGKelly also: “How about skin coloration-darker skins are obviously an adaptation to stronger sunlight-how long before the european immigrants in Australia start sporting natural tans?”

Soon, I hope, those guys are dying by the bus load from skin cancer. And this change over from European to darker skin would be a lot easier with a smaller population.


Are you driving with your eyes open or are you using The Force? - A. Foley

Hi EGKelly, This is a good thought:“Good thread! Getting back to the eyeglass thing-surely myopia is not a good thing for a hunter-gatherer society. If it is genetically
determined, why is it still with us (40% of americans are myopic)?”

I’ve been reading about hunter gatherer groups and they are noted for their huntin skills, silent and deadly. They rely now and did rely ages ago on being kinda close up and personal. Imagine getting an elephant with a spear? Have to be a lot closer (a whole lot closer) than I’d like to be do to that. And they didn’t use the little “L” shaped things that increased the power of the user.
The elephant hunting/killing story I read said that the pygmy stood in front of the elephant while it was moving to make the kill.

So between the tools used, the animals hunted and the hunters - they probably got pretty close up and they frequently hunted in groups. Several hunters in a semi-circle closing in towards the middle - seems like they wouldn’t need much in the way of power vision to kill with an ax or spear.

EGKelly also: “How about skin coloration-darker skins are obviously an adaptation to stronger sunlight-how long before the european immigrants in Australia start sporting natural tans?”

Soon, I hope, those guys are dying by the bus load from skin cancer. And this change over from European to darker skin would be a lot easier with a smaller population.


Are you driving with your eyes open or are you using The Force? - A. Foley

Whew. For a second I thought I was seeing double.

Heh. This morning’s paper had an article that said a previous study showing a link between myopia and night lights in children’s rooms has not been duplicated by a couple of other studies. Otherwise, yesterday, we could have jumped in here and pointed out that such myopia is environmental.

When I was a kid, I remember being very disappointed with an old microscope my uncle gave me. I just couldn’t see any more detail through it than I could with my naked eye, holding the object very close. I learned last year that that was associated with myopia. Perhaps myopia was a condition that allowed us to do fine work.


rocks

This from the Encyclopaedia Britannica, on Herbert Spencer:

“It should be noted that Spencer published his idea of the evolution of biological species before the views of Charles Darwin and the British naturalist Alfred Russell Wallace were known, but Spencer at that time thought that evolution was caused by the inheritance of acquired characteristics,
whereas Darwin and Wallace attributed it to natural selection. Spencer later accepted the theory that natural selection was one of
the causes of biological evolution, and he himself coined the phrase “survival of the fittest” (Principles of Biology [1864], vol. 1, p.444).”

As you know, Darwin’s “On the Origins of Species by Means of Natural Selection” was published in 1859, 5 years before The term “Survival of the fittest” was ever used.

However (and this is part of what frustrates me) when you look up “Biology” in Britannica, the VERY SAME SOURCE attributes the phrase back to him:

“In his theory of natural selection, which is discussed in greater detail later, Charles Darwin suggested that “survival of the fittest” was the basis for organic evolution (the modification of living things with time).”

Hmm… Anyone can see that there is a problem here.

The fact is, most people couldn’t care less because it’s all just a bunch of words. Even academicians get really sloppy about it. I found that most of the anthroplogy texts that I have that deal with human evolution choose simply to omit the offending phrase, while a few begrudgingly say things like “In popular writing, natural selection is often equated with “Survival of the fittest” in which the weak and the unfit are eliminated from the population by disease, predation or starvation. Obviously, the survival of the fittest has some bearing on natural selection; one need hardly point out that the dead do not reproduce. But there may be many cases in which individuals survive but do not reproduce…” William Haviland “Anthropology” seventh Edition (1994, page 66) [this is one of the most widely used university textbooks in anthropology, or at least was up until I quit teaching about three years ago- note the seven previous editions].

So knowing that "Survival of the fittest is Spencer’s term, not Darwin’s, knowing that literally it doesn’t really convey the central idea of natural selection to begin with, and recognizing that the ideas that Spencer was actually promoting were the foundations of the eugenics movement and influenced people like Hitler, I would say that this is a term that most people who are trying to teach others about evolution should either avoid (to me, a copout) or clear up from the outset.

But this is really a losing battle. Everyone seems committed to perpetuating this misunderstanding. People wonder why I’m so against it, but I just can’t figure out why everyone else is so invested in using a misleading, wrongly attributed shibboleth. This is the sort of thing Cecil is supposed to be good at debunking or elucidating.

And for the record, Africans did not “evolve” dark skin. Since the human species originated from Africa, it is most likely that our original color was darkly pigmented. Fair-skinned people have light skin because they have a gene that inhibits the otherwise natural production of melanin. White folks still produce it, but our skins only darken temporarily after exposure to the sun.

"The little “L shaped thing” is called an atlatl, and Jois is quite right that given the variety of hunting techniques, poor vision wouldn’t always be a big problem. Food sharing is a universal human phenomena, and those who can’t hunt usually get fed by their relatives, and usually find other ways to contribute to the family/group (by being a shaman, for example). Also, the whole “Hunter-gatherer” aspect of our past (and our present, for that matter) is terribly misunderstood. You can, for example, consider the Kalihari Bushmen, the Ituri “pygmies,” the Innuit, Pacific Northwestern tribes such as the Kwaikiutl, and Homo erectus. All were "hunter-gatherers, and all lived in different envirnment, hunting different types of game using different types of technology and having different marriage systems, kinship structures, and different relationships with other groups living in proximity. Hunting elephants on a plain with a group of people is a vastly different enterprise from hunting monkeys by yourself with a blowgun, trapping fish, or running game over a cliff. All of these are part of the “foraging spectrum.”

One other thing about textbooks Mentock- why is it that you consider the “legitimacy” of a textbook to be irrespective of its being right or wrong? I think the legitimacy of a text coes not from the reputations of the publishers or the authors, so much as the information it contains.

I recently saw the “Dummy’s Guide to Gourmet Cooking” and was struck by the fact that it was written by Charlie Trotter. I looked it over, and it’s actually a pretty good cookbook. And the fact that the movie “Heaven’s Gate” was directed by Oscar-winning director Michael Cimino and distrubuted by United Artists didn’t keep it from being a horrible movie that ruined Cimino and UA both.

And even “legitimate” textbooks has omissions and errors. Even The hallowed Encyclopedia Britannica is prone to that, it seems. Still, you seem to have forgotten the Origins FAQ that also states that the term “Survival of the fittest” is misleading and inaccurate, for the same reasons I stated. You can’t believe everything you read on the internet, but I consider that FAQ to be a pretty good treatment of basic evolutionary theory.

Trouts1 said:“And for the record, Africans did not “evolve” dark skin. Since the
human species originated from Africa, it is most likely that our original color was darkly pigmented. Fair-skinned people have light skin because they have a gene that inhibits the otherwise natural production of melanin. White folks still produce it, but our skins only darken temporarily after exposure to the sun.”

To what does this refer?

And this comes as a surprise:“Fair-skinned people have light skin because they have a gene that inhibits the otherwise natural production of melanin.” It’s the “inhibits” that I’m wondering about -


Are you driving with your eyes open or are you using The Force? - A. Foley

I penned the bit on skin pigmentation in response to the twoearlier postings that said “How about skin coloration-darker skins are obviously an adaptation to stronger sunlight” and “what caused Africans to have darker pigmentation” (I’m not quoting the second one word for word).

While it may seem like six of one and half a dozen of the other, the question is really when, how and why did light skin evolve, since it was the most recent change in that genotype. While H. Erectus was able to push out into southern Europe, its more likely that the lighter pigmentation was a trait found only in modern H. sapiens and possibly H. neandertalensis.

As for the term “inhibits,” white people have the genes for skin pigmentation, which is why we can get tans, but the production of melanin in our skin on an on-going basis is interuppted by other genes, causing fair skin. Several years ago Discover Magazine had a whole issue devoted to race (this was around 1995 or 1996, I believe) and there was an especially good article about the biology of skin pigmentation.

Just some FYI stuff.

Just checking 'bout the skin color thing because we were talking about how long it would be before the light skinned Europeans now living in Australia would gain the skin color adaptations suited to the climate.

Any opinions on that?


Are you driving with your eyes open or are you using The Force? - A. Foley

I don’t think the palefaces in Australia will gradually evolve darker skin pigmentation. The selective pressures that originally created differential skin pigmentation no longer exist. For that matter, Dark-skinned folks who move to Norway will probably not “lighten-up” either.

How long it would take, given a selective pressure, is a question that folks still debate.

Finally, traits do not evolve because there is a need for them.

I had heard a theory that darker skinned people don’t absorb Vitamin D as readily from sunlight. Where there’s lots of sunlight it’s no big deal, but in northern climates where the sun hides a lot during certain months, dark skinned people ended up with deficiencies. With a good diet, it’s not as much of a problem. This is a scanty memory of mine, so take it with a grain of salt.
Jill

http://www.csun.edu/~ms44278/skin.htm

That’s a paper somebody wrote that supports the ultraviolet light/synthesis of Vitamin D theory I had heard.

I’m a new guy around here and I had a couple things to say.

Firstly, there seems to be alot of superfluous discussion on this forum on the term “survival of the fittest” and its inapplicability to the evolutionary process. While I understand where you’re coming from, ultimately my feeling on the matter is that it’s pointless. Yes, evolution involves sexual as well as natural selection. The phrase “survival of the fittest” does not exclude the concept of sexual selection for one simple reason: the fittest genetic traits do survive throughout the generations. See talking about individuals over characteristics is pointless in a discussion on evolution since individuals survive for an insignificant amount of time. And as far as the term “fittest” being subjective when applied to sexual reproduction, yes it is, and no, it doesn’t make any difference, since just as environmental factors can capriciously change what makes one fit for simple survival, social factors can capriciously change what makes one fit for reproduction.

For this reason I embrace the term “survival of the fittest” regardless of who coined it, since it makes perfect sense to me.

Secondly, there seems to be a lot of focus on adaptation and tradeoffs. While it’s true that certain traits are more advantageous in some situations and more disadvantageous in others, there are very many traits which are simply superior than others. This has to be true, since we know that many people are born with disorders such as the aforementioned myopia which are simply bad traits. In other words, black skin (in humans) is an adaption (not a superiority, since dark skin is more prone to cancer, and apparently according to Cecil less sexually desireable, at least in Brazil), while good eyesight is a simple superiority.

So it is therefore perfectly reasonable to say that one species is more “evolved” than one another in the basis that some traits bestowed by evolution are, if not completely positive, far more positive than negative.