Cecil didn’t do justice to this one, unfortunately. He discussed it mostly on the topic of natural selection, but that isn’t the only force of evolution. There is also “artificial selection” ie: hybridization, domestication, etc. and Sexual selection. Sexual selection explains things like peacock feathers, which have no adaptive significance save the fact that they help peacocks get laid. Human sexual selection is quite plastic- it varies widely in time and space. Also, there is a distinction to be made between evolution and speciation. A population is pretty much in a constant state of evolution, although not a constant rate, but that doesn’t mean that populations are constantly engaging in speciation, at least not in an immediate sense. The bottom line is that culture has not triumphed over nature, halting any inexorable process in its tracks. That doesn’t mean though that we will turn into a new species any time soon.
First, Healym, please include a link to the article in question. (Copy the URL and paste it in the edit window, it will link automatically.) This allows us to respond to the same column. Most effective if the column in question is not recent (i.e. the same week.)
I did a search but couldn’t find the article in question. Maybe I just didn’t recognize it.
Now I’ll let David B. get back to you. I’m sure he’ll enjoy this one.
This one is listed in Cecil’s "Return of the Straight Dope. The URL is: http://www.straightdope.com/classics/a3_047.html
Who is David B? Please don’t sick some creationist on me- I’ve had it up to here with dinosaur tracks, the fourth law of thermodynamics, and lunar dust.
DavidB is the co-moderator of Great Debates, a skeptic and atheist who discredits Christian creationists every chance he gets. He’s on your side, Healym, and so am I.
>< DARWIN >
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Of course the human species is still evolving, the failure of some plagues to completely eradicate a population leaves only the resistant individuals, and voila, humans once again have evolved. Small Pox, tuberculosis, and hepatitis A come to mind.
I suspect that the immune system evolves more rapidly that other human properties because the pressure of natural selection is so high in the instances of communicable disease.
Now, other human qualities, such as intelligence, must also be continually evolving, though with considerably less selection pressure. Less intelligent people don’t necessarily make less babies, or die sooner, but I suspect there has been lot of historical pressure to be more intelligent, and aggressive, given our war torn heritage.
Trying to say which representatives of the human species are more evolved, in any respects, than other individuals is not a good place to go. I suppose that DNA analysis could shed light on this issue, if you want to get most everybody offended and pi$$ed off. It opens the door to the question, “Evolved for what? Better at doing what?”
That in turn reprises the ancient philosophy put forward by Aristotle that some people are more suited to lead, some more suited to follow…some more suited to be masters, some naturally suited to be slaves. Hold on, I’m about to puke. I told you that you didn’t want to go there.
It should be apparent that as our world changes more and more rapidly, the standard of what is more “evolved” also must change, probably too rapidly to assess in any meaningful way. Aggressive warlike traits that were important centuries ago can count against you today and land you in the pokey where reproduction is more, shall we say, challenging. And that is only one example, I’m sure there are plenty others.
“Remember, you are unique in all the world, just like everybody else.” (author unknown)
Bletchly, the selective pressures onthe immune system is a very good example of natural selection at work. I’m glad you mention the question of “Who is more evolved than whom?” because it brings up an important point: The distinction between adaptation and evolution. There is no such thing as an adaptation that is more “evolved” than another. That’s like saying that something is more created than something else. Characteritics can be more or less adaptive though. I suppose it would be correct to say that something has evolved more than something else insofar as it has changed more, ie our brain is more evolved than our skeleton, but that doesn’t mean very much. The fact that sharks and alligators haven’t “evolved” much in so many years (using that sense of the word) doesn’t signify a failure of the species to get better so much as it signifies the success of the original adaptations that made them what they are.
Another misunderstanding, this one blatantly made by Ceicil (Sorry, oh Great One) is to refer to natural selection as 'Survival of the fittest." This one makes anyone in the know bristle. That was Spencer’s term, not Darwin’s, and was used to establish “social Darwinism.” Survival is not the issue for Darwin. The real issue is reproduction. And “fitness” in Darwin’s use has nothing to do with strength or power, which is what Spencer was referring to. “Darwinian fitness” refers to the extent to which an individual is able to have grandchildren (and therefore great grandchildren and so on). Even the Great Cecil will have to acknowledge that he TOTALLY dropped the ball on that one.
I’m surprised you were the first to mention this “natural selection as ‘Survival of the fittest’” wording, Healym. One or two of the old time regulars has a bit to say whenever that phrase surfaces, too.
I think it is a catchy phrase and we’ll have it in the language for a while. Look at how long it has taken to kick Freud’s garbage out- how long it is still taking.
Oh, I’m gonna keep using these #%@&* codes 'til I get 'em right.
Bletchley wrote:
If they’re not making fewer babies there isn’t selection pressure against them, no?
The point, again, isn’t necessarily making more babies. If you have one child who lives to reproductive age, and indeed parents offspring, you are doing much better, in terms of Darwinian fitness, than someone who has ten kids, none of which reproduce. Especially since human children need so much parental investment, the “sow your seeds widely” strategy doesn’t always work very well. It’s theoreticall possible, therefore, that intelligent people can get away with having fewer children and investing more in them and still extend their Darwinian fitness better than less intelligent people who have lots of babies. The other big problem about discussing selection and intelligence, is that intelligence is a rather difficult thing to quantify, not to mention qualify. What, for example, are the relative adaptive merits common sense, booksmarts, strategic thinking, and being socially saavy? All of these things can be considered components of intelligence, and all of them will have more or less importance in a given context.
I think you’re being too disrespectful to Cecil (although you grovel convincingly after misspelling his name). I re-read that article, and he only refers to survival of the fittest in a parenthetical aside. Of course, others are still debating that issue. Otherwise, he pretty much covers the same territory that you do, there.
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rocks </font><font color=#DCDCDC>Sure would be nice to have a preview feature</font>
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I don’t think I was disrespectful to Cecil at all (alright, I didn’t run a spell check- so sue me). I simply stated that he very sloppily perpetuated a common misconception and that he didn’t do a topic much justice. That’s much more charitable and respectful than he is when someone gets something wrong.
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Cecil says this ONLY as a parenthetical aside? Whether he casually tosses it out as a fact or makes it the crux of his issue, it is still patently wrong and reinforces common misundestandings about the theory of evolution be means of natural selection that have been used to justify eugenics, genocide, and many instances of discrimination. All the worse that he is so casual about putting forth a specious idea so matter of factly. I repeat, Cecil would have torn someone else a new oraface for that.
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Others are still debating what? The fact that “Survival of the fittest” is a blatant misrepresentation of Darwinian theory? Virtually all of the introductory textbooks on evolution begin by debunking that one, or at least do so early on. Sure, there are lots of people who are still “debating” that one, but not anybody who knows anything about it. Lots of people are willing to debate all kinds of crazy things.
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“Otherwise he covers pretty much the same territory that I do” I admit that we come to similar conclusions, but Cecil doesn’t discuss the role of sexual selection and artificial selection in on-going human evolution, and I would argue that sexual selection is at least as important if not moreso than natural selection, since we have been able to use technology to adapt so successfully to most environmental variables. He doesn’t discuss speciation, doesn’t adequately distinguish between evolution and adaptation, and he doesn’t discuss Darwinian fitness. Furthermore, he says “The fundamental question isn’t whether people die young, it’s whether they fail to reproduce, or reproduce less abundantly than others. On
this basis we can say that the genes for the following physical types or traits are slowly disappearing from the population” Even here he gets it wrong. Sure, he’s right that survival isn’t the key issue, but neither is mere reproduction, as he would have you believe.
Finally, and this is somewhat less crucial, he isn’t quite right about reproductive isolation either. Reproductive isolation is a fairly relative concept. It can mean everyone on a desert Island or it can mean everyone in Australia. When he refers to Sickle-cell as being related to reproductive isolation, he’s talking about a population that is huge and wide-spread. Sickle-cell is not a condition in which reproductive isolation is really the issue. Hemophilia might be a better example.
<font color=#FF30c0>Healym</font>
1) There you go again! 2) Hmm…“patently wrong”? Who you got on your side? See 3. 3) Here’s one introductory text: “This is the principle of natural selection, or the survival of the fittest” (emphasis theirs) from the textbook A View of Life (p.582), by Salvador Luria, Stephen Jay Gould, and Sam Singer. It doesn’t sound so crazy when they say it. 4) You’re suggesting, it appears, that sexual selection is not natural selection. That’s much more misleading than Cecil’s column–which ain’t that misleading, for a less-than-600-word column.
I think your last paragraph is a fifth point, but you seem to agree with Cecil, but aren’t satisfied with his examples. It would take more than 600 words to really explain all the details. Darwin, for instance, wrote a book.
After all that, I still invite you to hang around. Just don’t use the phrase “so sue me” so cavalierly. Check out the topic What can Cecil do to me? in The BBQ Pit.
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rocks </font><font color=#DCDCDC>Sure would be nice to have a preview feature</font>
So how, again, is “survival of the fittest” wrong? Misleading, maybe, but i’m not seeing the asserted patent wrongness. It doesn’t say survival of the strongest, or smartest, or swiftest, or best, but the fittest, which is very ambiguous and can just as well be interpreted in the sense of Darwinian fitness. Granted no interpretation of the phrase makes it a clear and complete statement of the principles directing evolution, but it’s still not wrong.
Phantomwise
…never seen by waking eyes…
I never understood the visceral anger some people have against the phrase “survival of the fittest” either. The only thing that I see that people could object to is that the guy who originally used it, used it more as a sociological rule or justification. If, instead, you think of it as a biological tautolgy (who suvives? the fittest, who are the fittest? those who survive) it seems like a harmless little statement about evolution.
Getting back to the original post, don’t you think that if current evolution in humans is continuing today that it would need to be demonstrated by some apparent, visible difference from homo sapiens sapiens? If that is the case, then the reproductive isolation mentioned above would be necessary to produce another version of homo sapiens. I don’t see how that would be so hard to achieve For example, selective mutation and inbreeding (in the few cases when they can get it) among regular SDMB posters could lead to a new group of homo sapiens in several generations.
RM Mentock–Just an aside. This board is an established commercial format, not one created for or by Straight Dope.
SDMB probably cannot add its own spell check or preview feature or anything else on its own - that would most likely void the contract between SDMB and the owners of the format or at least those parts of their contract that deal with repairs.
However requests of this nature should still be sent to Tubadiva on the “About this Message Board” cite. She probably can pass on suggestions for the next update.
In the early twentieth century, the doctrine of “survival of the fittest” in natural populations was used by some individuals to defend gross social inequalities and ruthless competitive tactics in industry on the grounds that they were merely in accord with the “laws of nature.”
This philosophy was referred to by some as social Darwinism. However, in face, very little evolutionary change fits the concept of “nature red in tooth and claw.”
Fitness, as measured by population geneticists*, is determined solely by the relative number of descendents of an individual in a future population.
*The branch of biology that emerged from the synthesis of Darwinian evolution and Mendelian principles is known as population genetics.
Biology by Curtis and Barnes, 5th Edition.
Doesn’t make me rabid, might if I knew more about Social Darwinism.
Here’s an interesting link on this subject: http://www.sciam.com/askexpert/biology/biology32.html
This from the “Talk.Origins archive” (http://www.talkorigins.org/faqs/faq-intro-to-biology.html):
“The phrase “survival of the fittest” is often used synonymously with natural selection. The phrase is both incomplete and misleading. For one thing, survival is only one component of selection – and perhaps one of the less important ones in many populations. For example, in polygynous species, a number of males survive to reproductive age, but only a few ever mate. Males may differ little in their ability to survive, but greatly in their ability to attract mates – the difference in reproductive success stems mainly from the latter consideration. Also, the word fit is often confused with physically fit. Fitness, in an evolutionary sense, is the average reproductive output of a class of genetic variants in a gene pool. Fit does not necessarily mean biggest, fastest or strongest.”
The fact that the phrase appears in a textbook attributed to Stephen Jay Gould does, I admit, hurt my position. I would have to see the context within which the quote was used. Often in introductory materials teachers allow some slippery phrases to be used because they are trying to get the major point accross, and then the undo the damage later on. At any rate, I’ve heard Gould several times, and on at least one occasion I’ve heard him renounce the use of the phrase for the reasons I’ve outlined above.
Stephen Jay Gould’s halo has been slipping. Try the search for SDMB for a couple of threads on this subject.
Oh, I’m gonna keep using these #%@&* codes 'til I get 'em right.
This is a very muddy issue. I read an article recently (in Free Inquiry, I think) addressing this topic. Anthropologists (and ethnobiologists?) have a much different view of population genetics and the traits of modern humans than the general lay public. It was remarked that humans as recently as 500 years ago may have been different enough to make ethnic labels less than meaningful. Also, you must realize that species are not static - they are constantly changing. Sometimes the changes are small and relatively insignificant (sharks, alligators). That is one reason why piecing together a fossil record is such a challenge. Each individual fossil (or set of fossils) represents one individual in a progression, so designating the particular species and the transition points is very challenging. Often there will be two or three different samples found that will eventually be designated the same species - after comparison between the features of several samples.
So human evolution can in fact be proceeding with less than “visible” changes occurring.