I suppose it was inevitable. The latest issue of New Scientist has the obligatory article denying that intelligence can be defined and denying that humans can be separated into races. This is required political correctness in light of Jim Watson's comments from two weeks ago.
The politically correct author in this case is Robert J. Sternberg, a psychologist at Tufts University [Race and intelligence: Not a case of black and white]. He writes ...
A further hugely complicating factor is what we mean by the word "race". Populations in different parts of the world have clearly adapted to their environments in different ways. A trait that is beneficial in one environment may work against people in another. Obesity is a problem today because it once was beneficial to eat as much as one could while one could. Stratification - classifying people into categories of higher and lower status in a society - already occurs on the basis of weight just as it has on the basis of intelligence test scores.We all know what people mean when they talk about blacks and whites. Those are synonyms for Africans and Europeans. Unless Sternberg is being extremely pedantic, he's arguing that there are no such thing as distinct populations of Europeans and Africans that differ genetically. Races—or demes if you wish—don't exist according to him.
But there is nothing special about skin colour that serves as a basis for differentiating humans into so-called races. Skin colour correlates only weakly with genetic differentiations. Sarah Tishkoff, a geneticist at the University of Maryland, and Kidd have found that the genetic differences among black Africans are often greater than those between blacks and whites. The significance of those labels stems only from the fact that society has found it convenient to label races on the basis of skin colour.
Curiously, we do not apply the concept of "race" to colours of dogs or cats - or moths, for that matter. For some of these, colour can be important: being a black moth confers camouflage advantages in polluted environments and disadvantages in clean environments - and vice versa for white moths. Similarly, our ancestors in Africa were almost certainly dark-skinned because it provided better protection against the particular challenges of the environment, such as ultraviolet light. We could of course refer to moths as being of different "races". We do not, presumably because we are less interested in creating social classes for moths than for people.
The problems with our understanding of intelligence and race show that the criticism being levelled at Watson is based on science rather than political correctness. Intelligence is clearly a far more complicated issue than standard testing allows. And race is a socially constructed concept, not a biological one. It derives from people's desire to classify. Whether people with a genetic predisposition toward fatness will be classified as a separate race remains to be seen.
That's nonsense, of course, but it seems to be widespread nonsense. I'm beginning to wonder whether the discipline of psychology deserves to be called a science.
There's an interesting press release out today from Cold Spring Harbor Press [Scientists discover genetic variant associated with prostate cancer in African Americans]. It reports on a study of higher incidence of prostate cancer among African Americans compared to European Americans. The scientists identified a particular locus on chromosome 8 (8q24) that may contain a genetic variant that differs between the two groups.
Other studies show that the incidence of cystic fibrosis is higher among Europeans (whites) than among Africans (blacks).
How could there be a genetic difference between Africans and Europeans if there's no such thing as race? If these are just social constructs there shouldn't be any genetic differences that correlate with other features used to distinguish the two groups, right?
Obviously genes can vary with geography. I don't think any reasonable person would deny that. That isn't at all the same thing as saying that race is a biologically meaningful concept.
ReplyDeleteThe point Sternberg is making is that the races we've invented based on skin color are completely arbitrary classifications. Different human traits vary independently of each other, and they don't obey sharply differentiated boundaries, but vary along graduated clines. If we divided humans into groups based on some other characteristic, such as body proportions, skull shape, or blood type distribution, we would get a completely different set of "races."
Sure, traits like cystic fibrosis and susceptibility to prostate cancer are more or less prevalent among certain populations. But "Africans" or "Europeans" are only rough approximations of those populations. Because different human populations aren't genetically isolated from each other, they haven't become clearly defined and biologically meaningful races.
Larry, you are full of shit. No other way to put it.
ReplyDeleteIf you were not full of shit, we would call a child born to a white mother and a black father... what? In fact, we live in a virulently racist culture in which such a child is generally considered black. Let's recap the usual assignments:
Mother/father: child
White/white: white
Black/black: black
White/black: black
Black/white: black
Unless you are gong to argue that "blackness" and hence "African-ness" is dominant (in the Mendelian sense), you are utterly ignoring the way in which the words "black" and "white" are actually used. If you are making such an argument, you are, um, a crackpot.
So: which indefensible position will you now try to defend?
We all know what people mean when they talk about blacks and whites
ReplyDeleteOnly within a single social construct. I had a friend who was called "white" in Trinidad, and "black" in Canada. Same guy, and he was probably lighter skinned during the years he lived in Canada. On the other hand, when my father was young, Portuguese and Syrians weren't considered "white" (although they are in modern Trinidad). Try mapping North American ideas of race to Brazil. It just doesn't work.
Unless Sternberg is being extremely pedantic, he's arguing that there are no such thing as distinct populations of Europeans and Africans that differ genetically. Races—or demes if you wish—don't exist according to him.
Sadly, I don't have access to the full article. But I did not get that conclusion from the bit you quoted. The issue, as I see it, isn't that demes don't exist, it's that you can't map conventional concepts of race onto these demes, not in a way that is scientifically justifiable.
There's an interesting press release out today from Cold Spring Harbor Press...It reports on a study of higher incidence of prostate cancer among African Americans compared to European Americans. The scientists identified a particular locus on chromosome 8 (8q24) that may contain a genetic variant that differs between the two groups.
You can't use a study that assumes the existence of race to be evidence that race exists. The study used markers of "West African ancestry", and found they correlated with the target loci. That says nothing about "race". Are you saying that you wouldn't find differences in allele frequencies on this magnitude between the "Caucasoids" of Ireland and the "Caucasoids" of Bengal? Or even the between Spaniards and Finns? To have a biologically meaningful concept of race, you need to have consistently lower within group variation than between group variation, otherwise you're dealing with nothing more than a cline.
Other studies show that the incidence of cystic fibrosis is higher among Europeans (whites) than among Africans (blacks).
How could there be a genetic difference between Africans and Europeans if there's no such thing as race? If these are just social constructs there shouldn't be any genetic differences that correlate with other features used to distinguish the two groups, right?
Um, no. But if there is such a thing as race, where do you draw the lines between the "white" and "black" races? In Turkey? In Egypt? In Ethiopia? And you really expect studies based on North Americans to reflect the point where you flip from higher prostate cancer risks to lower ones? To sample two ends of a continuum and use that to show that there are two "races" just doesn't cut it.
If you're going to get persnickity about it, Europeans (and everyone else) are technically a *subgroup* of Africans. There goes your justification for calling them distinct groups. Plus, where do North Africans fit? How about the relatively light-skinned Xhosa etc. from South Africa?
ReplyDeleteLarry, you of all people should be aware of the problems of adaptive storytelling, which is exactly what goes on with allegedly genetic race-based differences in IQ. Read Gould's book on this fur goodnesssakes...
yes, race, or populations, or whatever you call them, is real:
ReplyDeletehttp://www.gnxp.com/blog/2007/01/race-current-consensus.php
razib: the (calculated?) lack of precision in your terminology does not inspire confidence in your ability to make careful or meaningful distinctions. Define your goddamn terms.
ReplyDeleteLet me just note that the issue of a) whether race is a biologically valid and useful concept as applied to humans is a separate issue from b) whether human populations markedly differ in genetic capacity for intelligence.
ReplyDeleteIn principle, any combination is logically possible: yes/yes, yes/no, no/yes, no/no.
Tupaia
Races—or demes if you wish—don't exist according to him.
ReplyDeleteThat's nonsense, of course, but it seems to be widespread nonsense. I'm beginning to wonder whether the discipline of psychology deserves to be called a science.
Psychology is nearly as scientific as biology.
Singling psychologists out is unfair when most geneticists make these same stupid comments to the press, as well. E.g. Craig Venter:
""It is disturbing to see reputable scientists and physicians even categorizing things in terms of race," said J. Craig Venter, whose company, Celera Genomics, recently completed mapping the human genome, which provided scientific proof that human beings are not divided into separate biological groups. As Dr. Venter says, "There is no basis in the genetic code for race.""
Lying has become institutionalized in the scientific community with these flakey kinds of public untruths and half-truths about 'inconvenient' sciences.
And the ones who do tell the truth...welllll. You can tell the truth or you can have a job, but it's a bit harder to do both.
I think "population" is too vague a word. "Race" typically refers to a small number of (fuzzy, permeable) divisions in the human species, continent-ranging superpopulations which are usually identified as numbering from 3-7. If "race" simply means "population", nobody is going to argue that there are not dozens, even hundreds, of human populations.
ReplyDeleteTupaia
In the context of research any word you use for some selected convenience grouping of phylogenetically related individuals below the species level will mean substantively the same thing: a selected convenience grouping of phylogenetically related individuals below the species level.
ReplyDeleteMeaningful distinctions between categories such as 'demes', 'races', 'subspecies', 'breeds', 'varieties', 'populations', 'lineages' aren't consistent with how they are used interchangeably in the (biology) literature.
Yes, there is a socially-constructed definition of "race" which is not a biological concept - in the same way that there is a socially-constructed definition of "fish" which includes whales and shellfish, which is not a biological concept.
ReplyDeleteHowever, some biologists like to tweak the definition of "race" - much as they have tweaked the definition of "fish" - to give it biological integrity i.e. to make it a synonym for "population".
While I respect the scientific integrity of these people, I don't think it's worth the effort. You run into the problems that we see in this thread. People just don't get it. My advice - avoid the word "race" as an ill-defined term just stick to "population".
Yeah, I agree with the last poster.
ReplyDeleteAnd frankly, some of you haven't been out in the public much.
You see, when someone (a non-scientist) thinks of a "black race", they lump people with darker skins together (e. g., people of African background with, say, Australian aboriginals) with IS nonsense.
So "race", as commonly understood by the public, is meaningless, whereas one can do some sort of "fuzzy set" taxonomy of human populations (e. g., wouldn't it be a waste of time to test a Swede for sickle cells?)
Also, remember that "politically correct" doesn't always mean "wrong".
Different human traits vary independently of each other...
ReplyDeletethis is obviously not true (assuming you're using the statistical meaning of the word independent). look at these individuals: clearly they're "white" but not European. There is extensive correlation structure among human traits.
...and they don't obey sharply differentiated boundaries, but vary along graduated clines
this is more true, but there are slight barriers to gene flow between continents that allow for grouping individuals at a continent level. however, the statement is entirely not true in some places, like the US-- the ancestors of "whites" and "blacks" in the US were not a random sample from Europe and Africa, so there tends to be some clustering.
And the ones who do tell the truth...welllll. You can tell the truth or you can have a job, but it's a bit harder to do both.
ReplyDeleteHah! Ain't that the truth.
I don't see any scientific way to classify people into groups, short of creating lineage trees based on genome sequence. Except in isolated, human populations, I doubt this data would lead to any simple or obvious groupings. Humans as a species are massively dynamic and interactive. So when we have everyone's genome sequence or hapmap or whatever, we'll see.
ReplyDeleteUntil then, any groupings - based on skin color, nationality, geography, head diameter, whatever, will all be totally arbitrary and based on human bias rather than science. Scientists should stay away from discussing these arbitrary groupings, unless there emerges data to support their existence.
bayman says,
ReplyDeleteUntil then, any groupings - based on skin color, nationality, geography, head diameter, whatever, will all be totally arbitrary and based on human bias rather than science.
I really don't know what to say to you. Do you honestly believe that it's "totally arbitrary" to distinguish between Asians and Caucasians? Do you honestly believe that my ability to tell whether a student is from Japan, Sweden or Ethiopia is based entirely on human bias?
Right now if an expert were given the complete mitochondrial DNA sequence of an individual they could make a very good estimate of their ethnic origin. Heck, they can even do that from DNA fingerprints.
How in the world do you think you can get away with calling this "totally arbitrary"? That's out-of-control political correctness and you should be ashamed.
Do you realize that you're dismissing all of those studies where genetic diseases are correlated with groups? How do you justify that? Do you think the scientists who do these studies are all racists?
george smiley,
ReplyDeleteLarry, you are full of shit. No other way to put it.
If you were not full of shit, we would call a child born to a white mother and a black father... what? In fact, we live in a virulently racist culture in which such a child is generally considered black.
Your comment is a prime example of what we're up against when we try and explain science to people who don't want to learn.
Let me give you an example that may help you understand where you've gone so horribly wrong.
Lions and tigers are classified as different species. However, they occasionally mate to produce hybrid offspring. Let's say we arbitrarily decide to call the offspring lions. Does that mean that all of a sudden it becomes impossible to distinguish between lions and tigers?
Of course not. When we talk about subpopulations, races, or demes, it's part of the standard definition to assume that they are capable of interbreeding and they will do so from time to time.
Try and keep up. I realize that these concepts may be a little difficult for you.
P.S. I'm sorry to hear that you live in a virulently racist culture. Have you ever considered moving?
ian asks,
ReplyDeleteBut if there is such a thing as race, where do you draw the lines between the "white" and "black" races? In Turkey? In Egypt? In Ethiopia?
I have no idea. I would draw the line based on genetic characteristics and not on geography.
There are literally hundreds of papers published every year defining those genetic differences. They are used to trace migration routes out of Africa, for example. If, as you imply, it's impossible to distinguish various groups of people genetically then does that mean you dismiss the out of Africa data?
And you really expect studies based on North Americans to reflect the point where you flip from higher prostate cancer risks to lower ones? To sample two ends of a continuum and use that to show that there are two "races" just doesn't cut it.
I'm well aware of the problems when using Americans in these studies. Normally when biologists attempt to define demes within a species they don't concentrate on the hybrid zones.
I never said that biology was neat and tidy. It's messy and there's no well-defined boundary around the various genetic subgroups within Homo sapiens. What I object to is using this messiness to try and claim that genetic subgroups just don't exist.
For some reason, people seem to have difficulty with these concepts when they apply to humans but they're perfectly comfortable with the idea that Saint Bernards are different from Golden retrievers in spite of the fact that they interbreed.
I never said that biology was neat and tidy. It's messy and there's no well-defined boundary around the various genetic subgroups within Homo sapiens. What I object to is using this messiness to try and claim that genetic subgroups just don't exist.
ReplyDeleteGenetic subgroups exist. They just aren't synonymous with "race". We can all see "race" (well, except Stephen Colbert), but we don't see it the same way. If everyone has a different definition of race, how can it be a useful scientific concept?
The only way you can come up with discrete categories of "race" is if you discard data which doesn't fit the model. "Race" is a discrete idea. Until there is data that human variation is discrete and not continuous, and that variation maps onto someone's idea of race, there's no scientific justification for race.
Genetic subgroups exist. They just aren't synonymous with "race"
ReplyDeletethat's simply not true, at least in the US (where the proposition has been tested).
consider this paper, which tests whether self-reported race lines up with genetic data:
"Subjects identified themselves as belonging to one of four major racial/ethnic groups (white, African American, East Asian, and Hispanic) and were recruited from 15 different geographic locales within the United States and Taiwan. Genetic cluster analysis of the microsatellite markers produced four major clusters, which showed near-perfect correspondence with the four self-reported race/ethnicity categories. Of 3,636 subjects of varying race/ethnicity, only 5 (0.14%) showed genetic cluster membership different from their self-identified race/ethnicity."
Human populations can evolve several distinctive traits, phenotypic and genetic, specially considering geography, genetic drift, different environmental conditons, and different selective regimes.
ReplyDeleteTooth morphology is an excellent race identifier, for instance.
However popular notion of races indeed are inaccurate on sevral counts; for instance, there are several "black" races within africa.
Also, that we can find evident genetic traits that cluster with race does not give free pass to ignore all the standing variation that does NOT cluster with race,and which as far as I understand, is much greater. The same occurs for phenotypic traits. There is a great amount of standing phenotypic variation that does not line up well with race. One of such traits is IQ scores.
I don't see any scientific way to classify people into groups, short of creating lineage trees based on genome sequence.'
ReplyDeleteThat's exactly the wrong way to go. Trees are for modeling population history, and you don't need the complete tree of every individual if you want to know if traits correlate in the present.
Scientists should stay away from discussing these arbitrary groupings, unless there emerges data to support their existence.
What is special about people - we make inferences about population structure all the time in other species without sequencing every individual! Is all of population genetics arbitrary? Should scientists stay away from it until data somehow "emerges" by itself?
a great amount of standing phenotypic variation is epigenetic.
ReplyDeleteaslo, while scientists can make distinctions among races, it is interesting to point out that they can also be lumped together into bigger clades, correct me if wrong but I understand that some people we consider "black" are actually more closly related (share a more recetn common ancstor) with white people thatn with other races of "black" people; my guess is they probably share distinctive phenotypic traits.
Well, Larry. You certainly did not address the substance of what I actually wrote. I do understand the science, I do understand hybridization, and you have poor reading comprehension.
ReplyDeleteTry again.
Larry asked if I have considered moving. If I did, I'd have to give up a great job and an RO1, and desert several grad students, friends, and family. I'll try to fight the good fight here, thanks.
ReplyDeleteGeroge Smiley asks,
ReplyDeleteWell, Larry. You certainly did not address the substance of what I actually wrote. I do understand the science, I do understand hybridization, and you have poor reading comprehension.
Try again.
Okay, I'll try again.
Here's the complete text of your earlier comment.
Larry, you are full of shit. No other way to put it.
If you were not full of shit, we would call a child born to a white mother and a black father... what? In fact, we live in a virulently racist culture in which such a child is generally considered black. Let's recap the usual assignments:
Mother/father: child
White/white: white
Black/black: black
White/black: black
Black/white: black
Unless you are gong to argue that "blackness" and hence "African-ness" is dominant (in the Mendelian sense), you are utterly ignoring the way in which the words "black" and "white" are actually used. If you are making such an argument, you are, um, a crackpot.
So: which indefensible position will you now try to defend?
I'm well aware of the fact that some of you live in virulently racist culture where the words "black" and "white" are loaded with all kinds of baggage.
I'm well aware of the fact that stupid questions about whether a child is black or white can confuse people when they think about genetically isolated populations (demes) within a species. I'm insulted that you would ask me that question. That's childish.
The fact that terms such as "black" and "African" can be misused is not an excuse to abandon all your mental facilities when you talk about demes. Demes exist, in spite of the social context.
Instead of tossing out charges that I'm full of shit or a crackpot, why not address the issue I raised?
Is race a biological concept or not? Is the human species subdivided into populations (demes) of not? If you really understand the science then you will have to admit that there is a biological concept of race and it applies to humans just as it applies to all other species.
Perhaps you were just being politically correct? Perhaps it's unwise of you to admit that races exist for fear of damaging your reputation? I can understand this after seeing what happened to Watson but don't be hypocritical about it and try to pretend that there's a scientific reason for denying the existence of demes.
You're denying it for cultural reasons not scientific ones.
I think clades, rather than demes, will correlate better with genetic and morphological traits. Deme as a mere geographic aglutinator is not so enlightening.
ReplyDeleteIt is cladistically ncorrect to treat all africans as if belonging to a same race ("black" or in your case "the african deme")
The fact that terms such as "black" and "African" can be misused is not an excuse to abandon all your mental facilities when you talk about demes.
ReplyDeleteNo, it is not. It is, however, a complicating factor that necessitates great care with language, so that it is clear what you are talking about: a scientific question or a constellation of social, political, economic, and, yes, moral issues. That you don't realize this is evident in the post at the top of this thread: "We all know what people mean when they talk about blacks and whites. Those are synonyms for Africans and Europeans."
What you are doing here is rather recklessly (or intentionally?) conflating the constellation of social aspects of race with a rather narrow scientific question.
"Demes exist, in spite of the social context." Well, no shit. I for one did not say otherwise. But much of what you are writing, unintentionally or otherwise, obliterates that critical distinction. I think it's either exceedingly naive, or startlingly dishonest.
Having followed your behavior on the internets since before the www existed, I don't think you are intentionally deceptive, but issues of race are funny, people can have astounding blind spots, and I don't actually know you. What I do know is that you wrote this:
We all know what people mean when they talk about blacks and whites. Those are synonyms for Africans and Europeans
...knowing perfectly well, apparently, that "black" is a social designation, and "african" is an indication of lineage, all the while claiming - as you do - that you are having a conversation about science. I call that bullshit.
Perhaps you were just being politically correct?
You tell me. I don't know what's politically correct and what's not.
Perhaps it's unwise of you to admit that races exist for fear of damaging your reputation? I can understand this after seeing what happened to Watson but don't be hypocritical about it and try to pretend that there's a scientific reason for denying the existence of demes.
You're denying it for cultural reasons not scientific ones.
You are attributing to me a series of views on population structure that I did not endorse and do not hold. Perhaps you are still having more trouble with reading than with writing.
I do think Watson is a moron who largely did it do himself. Public figures in positions of responsibility have some responsibility to be circumspect in their public pronouncements.
His hope is that everyone is equal, but he counters that "people who have to deal with black employees find this not true".
That is not science, it is overt racism justified with anecdotal and subjective recollection. And someone who metes out such drivel in an on-the-record interview is unfit to serve as the Chancellor of one of our greatest research institutes (which Watson did lead for decades with some distinction).
"How could there be a genetic difference between Africans and Europeans if there's no such thing as race? If these are just social constructs there shouldn't be any genetic differences that correlate with other features used to distinguish the two groups, right?"
ReplyDeleteWhy not? I think that even if we subdivide europeans, or africans, randomly or not, we'd find differences withing these groups, wouldn't we? It's not like all people from a single continent are clones, nor have the exact same way of living, concerning to non-genetic diseases.
I'm not arguing that "there's no such thing as race", though. I think that most of the battle over the term is somewhat fruitless and stupid. In one side there's some sort of fetishism, an adoration of the term by its own sake, and in the other side, the opposite.
I'm more nested within the so called "deniers" group, though, in the sense that I think it's a misleading, ill-defined term, that the fetishists will always insist that it's "true" while seldom defining it in any way that would make it much more meaningful than something less haunted by the essentialist ghost, like "population".
Or will we argue that anywhere we can distinguish two populations genetically there are races, resurrecting old atomistic concepts that had almost a race per country? Ironically, I think these "races" are possibly more relevant than "big races", by the extension of the logic that, for medical reasons, for example, one's familial history is more relevant than one's "big race". And perhaps we could even say that there are cryptic races, whenever we can't easily see phenotypic difference. When the population is quite homogeneous, all it means is that most of the population is hybrid, while there are only rare spots of pure races, infra-races, or whatever.
Propositions like these could probably be defended as true, judging by genetics alone and the fact that there were proposals of much more atomistic classifications of human races, ranging from 7 to nearly 60.
Even some wordings like "genetic distinct" would ideally be avoided, if we care about what people will (mis)understand. For some reason "distinct" sounds like we're saying of something as distinct as a cat and a dog, IMO, despite of the fact that even two brothers are genetically distinct.
"Genetically distinguishable", despite of being almost the same wording, gives me the impression that dramatically reduces the possibility of the exaggeration of the degree distinctiveness.
I'll not even start to actually assert that "there are no races" or whatever, arguing that it's somehow impossible to distinguish, differentiate, people from different places, label them with the names of the places for convenience, "because there is clinal variation" or variation within groups. These facts do not make impossible to label populations, as everybody unavoidably does. Is it really worthwhile to push the term "race" for these labels, is there information being missed when we don't use it? Or is there some needless noise possibly being added by the muddiness of the broad concept?
What a fascinating debate. With this PC approach to human populations, if a certain unique biological population were on the verge of extinction there would be no scientific or genetic justification to save them. :(
ReplyDeleteWith such a PC approach to human populations, if a unique population was on the verge of extinction (black moth)then there would be no scientific or genetic justification for the preservation of such population and therefore they would die out. What a loss to human diversity. :(
ReplyDeleteHow would someone technically (as a geneticist) describe a "population" of northern European ancestry who has the genetics for light hair, light eyes, white skin, and a carrier of recessive genes? thank you.
ReplyDeleteHow would someone technically (as a geneticist) describe a "population" of northern European ancestry who has the genetics for light hair, light eyes, white skin, and a carrier of recessive genes? thank you.
ReplyDeleteFrom a forensic anthropologist's perspective, race is a very real thing we use to identify human skeletal remains on a daily basis. Morphologically speaking, races all have unique characteristics that are found in the skeletal remains. For example, Native Americans and Eskimos have incisor shoveling. The biodiversity in this world, however, is greatly increasing due to mixed races. With this said, a hundred years from now it may be difficult to use the current "race" criteria we have established in the field. In regards to intelligence....race has ZERO influence on intelligence.
ReplyDeleteRace (human classification) - Wikipedia
ReplyDeleteMorphologically differentiated populations.
""...Traditionally, subspecies are seen as geographically isolated and genetically differentiated populations. That is, "the designation 'subspecies' is used to indicate an objective degree of microevolutionary divergence."
One objection to this idea is that it does not specify what degree of differentiation is required. Therefore, any population that is somewhat biologically different could be considered a subspecies, even to the level of a local population. As a result, Templeton has argued that it is necessary to impose a threshold on the level of difference that is required for a population to be designated a subspecies.
This effectively means that populations of organisms must have reached a certain measurable level of difference to be recognised as subspecies.
Dean Amadon proposed in 1949 that subspecies would be defined according to the 75% rule which means that 75% of a population must lie outside 99% of the range of other populations for a given defining morphological character or a set of characters.
The 75% rule still has defenders but other scholars argue that it should be replaced with 90 or 95% rule.
In 1978, Sewall Wright suggested that human populations that have long inhabited separated parts of the world should, in general, be considered different subspecies by the USUAL criterion that most individuals of such populations can be allocated correctly by inspection..
Wright argued that it does not require a trained anthropologist to classify an array of Englishmen, West Africans, and Chinese with 100% accuracy by features, skin color, and type of hair despite so much variability within Each of these groups that every individual can Easily be Distinguished from every other.
However, it is Customary to use the term Race Rather than Subspecies for the major subdivisions of the Human species as well as for minor ones.".."
I can see why you're anonymous. Sure, you can tell an Englishman (or one whose ancestors have been English for a thousand years or more) from a West African from a Chinese. But the problem with races comes when you look at the people between those widely separated points. Almost all variation between human populations is clinal, and the clines are quite gradual. Try a transect from West Africa, through the Pillars of Hercules, up through Normandy to England, and tell me where the race boundary is.
ReplyDelete