blutoski
Penultimate Amazing
- Joined
- Jan 10, 2006
- Messages
- 12,454
Have you ever tried googling that word?
No, why?
Have you ever tried googling that word?
I don't understand the analogy, if it's an analogy.Well, this makes me query. Colours, there are definable focus-cluster points for them, as we can determine the gradient of pixels of said colour in each mix, even if visibly we can't (the same with biological ancestral-groups/ecotypes/races... semantics).
Ethnicity is more precise and specific than race, as long as the term is not misused. It is more precise because it does not imply any biological relationship which may or may not exist and it is more specific because there are many more recorded ethnicities than races,Ethniticity can be used to denote both cultural and genetic groupings, as it is it's a lot less specific than "race", or more encompassive and adaptable to any colloquial usage that might be begged of the writer.
Which groupings are these? How are these groupings established?Personally I have little issue with it, but to say that race is a meaningless term as per taxonomical contexts can only be a made against the choice of word, not for the consistently observed groupings which come across fairly evidently in most related fields.
I do not know what this means. I suspect it is a reference to a misunderstanding.The fact that we can approximate many levels and extents of ancestral admixture is not a blurring of the concept of any taxonomy applied to humans.
The link is about chimps, not dogs. Also what is the point?Furthermore, one of the points often raised in these discussions is that human beings are supposedly more genetically diverse than dogs are, if looking at heterozygosity (humans 0.776, dogs 0.401).
Sounds intriguing. Can you elaborate on this?
If you wish to make the case that applying a standard commonly used in taxonomy will lead us to identify subspecies in humans, then you should make that case.For other creatures (ie non-human) we classify via the international codes or the phylogenic codes, and related scientists do not always agree... yet I've never heard one to claim one or the other of being a social construct, let alone the concepts thereof in applying to be that.
You seem to be the only one using it. I wonder where you picked it up.No, why?
You seem to be the only one using it. I wonder where you picked it up.
Above species level, yes. Below it, no, of course not. That's countered just by the nature of what "species" are. Sometimes groups within a species might just happen to be that way, but such groups don't just poof out of existence the instant one individual from one group reproduces with one from the other.In modern taxonomy, you want your groups to be monophyletic.
Which is why there is not such a requirement for something below species level; things defined that way would just be species, not something else.In order for a population to qualify as a species it must be reproductively isolated.
Not really. I mean, we do generally end up with lines, with a bit of fuzziness to them because these aren't separate species. But that isn't the most useful perspective from which to look at it. The real point is the regions behind/between such lines; the cells of the honeycomb, not the walls between cells. As I said before (and as Darwin devoted at least one chapter to in TOoS), the way evolution works in a widespread species is that one successful group emerges from somewhere along the line and grows and spreads, crowding out others if there are any around. The "line" you're talking about is just wherever two growing bubbles happen to touch each other. But within each one's own region, not along the line, recent distinct common ancestry yields relative uniformity, not smooth gradients. Gradients can develop afterward, if given enough time, but then they're always subject to getting disrupted again if another bubble expansion comes along later.What we want is a dividing line.
No. The statistical method by which the basic genetic groups were identified was to find correlations between alleles: cases in which an individual's possession of one allele was correlated with possession of another, and another, and so on. Correlation between two or more items like that is simply a numerical fact about them which can only be found, by measuring & counting what's actually there in the real world, not arbitrarily made up. And, since genes on nuclear chromosomes other than Y are free to mix in any combination with each new generation, there's no particular reason for batches of certain alleles to keep appearing in the same individuals as if they were stuck together, unable to separate and form random new combinations... at least, not in an undivided population. The only way for correlations like that to happen is when the population actually is divided based on inheritance from mostly (although not necessarily perfectly) separate sub-populations; correlations in clusters of alleles reveal relatedness. (In fact, they do it at every scale from the hugest to the tiniest, which is why correlated allele clusters can be used to identify families or clans.)That's a necessary consequence of the sampling and the statistical methods used. It doesn't mean that there were separated ancestral populations
I'm thinking you're misremembering something.UBC. Introduction to Anthropology. My wife used it from time to time (she was a BA Anthropology)
Separate subspecies disappear when they thoroughly mix. If you can't identify separate units, then there are no separate units.Above species level, yes. Below it, no, of course not. That's countered just by the nature of what "species" are. Sometimes groups within a species might just happen to be that way, but such groups don't just poof out of existence the instant one individual from one group reproduces with one from the other.
If the genes of two populations perfectly mix, then there can't be any difference between them.Which is why there is not such a requirement for something below species level; things defined that way would just be species, not something else.
Alright. What happened here?I wish there were a way to have listed the stunts race deniers like to pull, ahead of time, and start checking them off one by one in the thread as whoever's in the thread goes through them, without the participants in the thread seeing it ahead of time themselves. "Trying to equate race with species" or "Pretending race is supposed to be species" or such would have been one of the items on the checklist. And it's pure straw. You know perfectly well that nobody's claiming that humans aren't all the same species.
That's not how evolution works. You're talking about group selection but it is highly dubious if such a thing exists at all.Not really. I mean, we do generally end up with lines, with a bit of fuzziness to them because these aren't separate species. But that isn't the most useful perspective from which to look at it. The real point is the regions behind/between such lines; the cells of the honeycomb, not the walls between cells. As I said before (and as Darwin devoted at least one chapter to in TOoS), the way evolution works in a widespread species is that one successful group emerges from somewhere along the line and grows and spreads, crowding out others if there are any around. The "line" you're talking about is just wherever two growing bubbles happen to touch each other. But within each one's own region, not along the line, recent distinct common ancestry yields relative uniformity, not smooth gradients. Gradients can develop afterward, if given enough time, but then they're always subject to getting disrupted again if another bubble expansion comes along later.
There is no way to distinguish between a cluster that exists in the real world and one that results from "clustered sampling". If you take a bunch of samples in village A and another bunch in village B 2000 km away then you will find two clusters. The people in either village are more closely related to each other than to people in the other village.No. The statistical method by which the basic genetic groups were identified was to find correlations between alleles: cases in which an individual's possession of one allele was correlated with possession of another, and another, and so on.
I don't understand the analogy, if it's an analogy.
Ethnicity is more precise and specific than race, as long as the term is not misused. It is more precise because it does not imply any biological relationship which may or may not exist and it is more specific because there are many more recorded ethnicities than races,
It is not a genetic grouping.
Which groupings are these? How are these groupings established?
It’s become a popular view that the human species is extraordinarily homogeneous genetically when compared to most other species.[15] This notion argues against the existence of human races, because very little genetic variation within the entire species means there cannot be much variation between major human populations. Before examining this further, we should first inquire about what is meant by ‘genetic diversity.’
Because little can be learned from a locus that is the same in every individual, the study of phylogenetics depends on polymorphic loci. Over the past few decades, methods have been developed that allow different kinds of these polymorphic ‘markers’ to be assayed in individuals. Prior to the 1990s, genetic diversity was usually inferred from classical (non-DNA) polymorphisms, such as blood groups, serum proteins, allozymes and immunoglobins. Later, restriction enzymes were employed to produce a useful class of marker at the DNA level, restriction fragment length polymorphisms (RFLPs). Other loci such as mitochondrial DNA (mtDNA), Alu insertions, minisatellites, single nucleotide polymorphisms (SNPs) and microsatellites (STRPs - short tandem repeat polymorphisms) have also been utilized for population genetic studies. Due to their high polymorphism, rapid mutation rate and random distribution throughout the genome, microsatellites are probably the most important class of marker in use today.[16] Highly variable loci are an advantage in phylogenetics because they can provide the finer resolution necessary for distinguishing closely related populations (such as subspecies).
The majority of population genetic studies over the past decade have investigated the various regions of mitochondrial DNA, a molecule that resides in the cytoplasm outside a cell’s nucleus. mtDNA contains 37 genes and is comprised of 16,569 base pairs in humans. Because it is haploid and maternally inherited, mtDNA has an effective population size about one-quarter that of the autosomes (the non-sex chromosomes). It’s easy to collect, has a relatively high mutation rate, and in particular, its lack of recombination allows for a straightforward assessment of the relationship between haplotypes. Lack of recombination also means that all parts of the molecule are completely linked, which prevents independent evolution of mtDNA’s 37 genes and non-coding control region. For this reason, mtDNA is considered a single genetic locus for phylogenetic purposes. Humans have relatively low mitochondrial diversity compared to the other great apes, and reports of this are mostly responsible for the belief that humans have low genetic diversity. However, mtDNA makes up just a few millionths of the human genome,[17] and as a single locus, carries little statistical weight.
When allele frequency data are used to estimate genetic diversity within a population, a frequently reported statistic is the average number of alleles per locus (A), but because rare alleles do not contribute much to overall diversity, the most informative statistic is average heterozygosity (H). This is estimated from both the number of alleles and the frequencies at which they occur, and is generally defined as the percentage of individuals in a population that are heterozygous (have two different alleles) at a random locus. In general, genetic diversity is synonymous with mean heterozygosity.
...
In conclusion…
Some will find provocative the idea that humans display a subspecies-like population structure, but given that the major human subdivisions revealed by modern genetics had already been recognized as early as 1775,[112] it shouldn’t be as provocative as the alternative notion, i.e., that human races don’t exist.
So if we do belong to different biological races, what, if anything, does this mean? Subspecies are closely related by definition, and human races appear to be less genetically distant than the major phylogroups of many other species.[113] While FST values for neutral variation are by no means negligible from a population genetics point of view, it’s significant that the overwhelming majority of genetic variation is found within populations, reaffirming the importance of treating people as individuals. It’s also significant that the FST value for the most prominent racial trait - skin color - has been estimated to be about 0.60,[114] which means that the visible variation between races greatly exaggerates overall genetic differences. Admixture in some populations further clouds the picture. The average European contribution to the gene pool of American blacks has been found to be about 20%,[115] and admixture between the major races in some other regions is substantially higher.
Nevertheless, when the taxonomic term is used consistently across species, it’s difficult to see any justification for the common assertion that human races are merely ‘social constructs.’ The motivation behind the assertion is a positive one, but denying biological realities at the outset is unlikely to lead to productive social dialogue on coping with human differences.
The link is about chimps, not dogs. Also what is the point?
Sounds intriguing. Can you elaborate on this?
"I am not aware of any other mammalian species where the constituent races are as strongly marked as they are in ours… except those few races heavily modified by recent human selection; in particular, dogs."
You're talking about group selection but it is highly dubious if such a thing exists at all.
That analogy would imply that current humans are a mixture of different "prime races".It is, to your bracket of numbers with a dividing line in the center. Your exercise shows that through smooth, even continuance you can apply a variety of groupings that would be meaningless in the real world. We can do that to with colours, though as with biology you can approximate the pixels in, for example, a paint and see its blend and degrees thereof, making a mix between yellow and red "orange" to the eye but on a microscopic level you can see the isolated parts of each colour. Ergo, a spectrum or even at times a smooth gradience between two classified prime colours does not negate these prime colours or make the classification meaningless, because (again as with race) there is no at average smooth gradience between the prime colour hubs (bigeographical populations/ecotypes/races).
Well, that is true for race which is exactly the problem.It is less precise simply because it includes biological as well as non-biological constructs into it. Making the application much more flexible, with a greater variety for denotation-vs-connotation.
I have never heard of either of those. I don't think that these terms are used in contemporary biology.Depending on if we use the supra-race or meta-race groupings, the same ones come out of biology.
Source?If we're applying the genome project, there are nine different main clusters (i.e supra-races) with forty-two populations(i.e meta-races).
What's the evidence for that?The issue is not that you can get any old group to fit any old category, as the requirement for them follow out of biological ancestry where a given population has evolved/developed in a specific geographic location, having phylogenetically phenotypic characters with which they share more closely to each other than with extra-groups in their surroundings due to genetic partitioning between them and... that the phylogenetic distribution follows through genetic traits in accordance with taxonomical conventions.
What should I take away from this FAQ?Goodrum explains it well in his FAQ regarding race:¨
Obviously there is something very geographical about these groups. I am not sure what else to say since I have never heard of either Coon or Brace.Now, either there is something very biological about these groups and how they are observed or... it's an increadible coincidence they are even comparable with each other from two authors who couldn't have been more of their ideological opposites. So, in any case, the question of whether taxonomical groupings (species, sub-species, breeds, races, ecotypes) are meaningful or not, or to which extent they are meaningful, is not interchangable with whether or not they are biological actualities.
Largely because you cannot distinguish subspecies when faced with clinal variation.Again, why is race not a notably biological reality, in light of the more notable groups that consistently are categorized as the genetic marker hubs being main biogeographical groups of ancestry/heritage???
Hmm. It doesn't seem like heterozygosity is a good measure for genetic diversity outside of specific circumstances.Ah, might've used the wrong link then (my bookmarks is a mess). It is more elaborated in the above quoted FAQ of Goodman however, regarding the relevance of heterozygosity-is-genetic diversity.
I think you mistraslated group selection. FWIW, it's almost universally rejected.I know this was in reply to Delvo but I am not sure it is highly dubious. It is not settled, to my knowledge, but I believe it is an interesting sub-field of research, such as the "Dual inheritance theory". Expectedly, Lewontin (to name one) is pretty much against (as he is with basically anything that looks at human behaviour et al through a darwinian lense, which apparently is only to be reserved for the non-human members of the animal kingdom).
The conclusion does follow from the condition in theory, but the whole proposition is inapplicable without that condition, and that condition is known in reality to be false. They've been observed and identified and mapped. That part is over. Discussing what conclusions we might draw if the observed facts were different from what they are is moot. You can't theorize your way out of the facts.If you can't identify separate units, then there are no separate units.
The observed fact is that the present human populations have not mixed back together since the last time they separated, so any idea that depends on "when they thoroughly mix" and "if the genes of two populations perfectly mix" clearly can only possibly be applicable to some other species at this time (or maybe this one at some other time). It doesn't matter how true your propositions theoretically would be under one set of conditions when you're trying to apply them under another set of conditions. You can't theorize your way out of the facts.Separate subspecies disappear when they thoroughly mix... If the genes of two populations perfectly mix...
Or, at least, not stay that way indefinitely. But nobody expects divisions within a species to be permanent. Conditions change, and when they do, you can get either re-convergence or speciation, neither of which means that the two or more types within a species didn't exist while they existed. And there are other factors in the distribution of populations within a widespread species which can make what you're talking about inapplicable to a given species at a given time, so, taken as a blanket statement, it's just plain false. For one thing, genetic similarity across a region doesn't mean there's free gene flow within that region. It can also mean that the genes freely flowed before even if they don't now, or that the region's population was established by rapid expansion of an originally smaller population. Also, no rate of gene flow between two regions means that they must have a single mixed gene pool. It takes time once it gets started, so the real world contains cases where it has been long enough in one species at one time and cases where it hasn't in another species or at another time.The gene flow between two populations must be limited relative to the flow within either population. Otherwise the populations won't be separate subspecies.
Then I'll ignore the stuff where it looked like you were, as if it weren't there. That was my only issue with that part.I did not equate race with species
More about the fact that sometimes a population with a small territory expands? What else do you want to hear about it?Tell me more about how you think that works, please.
It's trivially easy when the scale of the genetic clustering effect is much larger than the scale at which the samples could be said to be clustered. (See below.)There is no way to distinguish between a cluster that exists in the real world and one that results from "clustered sampling".
Yes, exactly. So how do you explain what's happening when two villages 2000 km apart have the same genetic cluster?... especially when it's a different cluster from the predominant one in another village just 200 km away from one of those two? Because that is the observed situation in humans, as the map I linked shows. Pondering how we might react if villages over about half of a continent or more didn't share a genetic cluster, when it's already solidly established that that is not the case, is moot. You can't theorize your way out of the facts.If you take a bunch of samples in village A and another bunch in village B 2000 km away then you will find two clusters. The people in either village are more closely related to each other than to people in the other village.
OK, but it doesn't need to. Intermediate states can arise either from mixing like that, or as part of a gradual gradient, or as a remnant of an old gradient that's been smashed since then by expansion of A's and/or B's type(s), or by coming from the original more inclusive population that A&B got narrowed down from by the founder effect... none of the mechanisms for it make any difference to the subject here. The issue is where such intermediates are distributed and how well they actually grade into each other. And the way to find out is to sample a bunch more between them, and off to the sides, and all around. And that's been done, and the answer is that there are broad regions of one type or another, which meet at only narrow zones of brief intermediate grading: AAAACBBBB, not ADEFCGHIB. No matter how it got that way, that's the way it is. And how we might describe the situation if the genetic clusters we observe had had some other distribution instead of the one we've observed, or how likely or unlikely we might have thought any particular process was to lead to the observed distribution if we hadn't already observed it, is moot. You can't theorize your way out of the facts.Now if you sample a third village C half-way between the two you may find that you can express the local population as a 50/50 mix of both clusters (not really how the statistics work). But that doesn't mean that village C was founded equally by people from the two villages A+B.
Perhaps you should think a little about the difference between "repeatedly asserting" and "convincingly demonstrating" facts.You can't theorize your way out of the facts.
I just tried to correct what seemed to be misunderstandings. What rest is that?You're picking out the fragments of population dynamics that you want and pretending the rest of it doesn't exist.
You think that group selection happens, right? I would like to know how you think that can be.More about the fact that sometimes a population with a small territory expands? What else do you want to hear about it?
How do you get that from the map?Yes, exactly. So how do you explain what's happening when two villages 2000 km apart have the same genetic cluster?... especially when it's a different cluster from the predominant one in another village just 200 km away from one of those two? Because that is the observed situation in humans, as the map I linked shows.
As I said, that's basically an artifact, or perhaps a misunderstanding. I take it the map is your only source for that assertion?The issue is where such intermediates are distributed and how well they actually grade into each other. And the way to find out is to sample a bunch more between them, and off to the sides, and all around. And that's been done, and the answer is that there are broad regions of one type or another, which meet at only narrow zones of brief intermediate grading: AAAACBBBB, not ADEFCGHIB.
What you find the world over are smooth gradients with relatively small discontinuities where something inhibits gene flow.
Perhaps you should think a little about the difference between "repeatedly asserting" and "convincingly demonstrating" facts.
That analogy would imply that current humans are a mixture of different "prime races".
In a way that is true. The out-of-africa human race has admixture from neanderthals, denisovans and who knows what. But I think that's not what you mean?
Well, that is true for race which is exactly the problem.
Source?
What's the evidence for that?
What should I take away from this FAQ?
Obviously there is something very geographical about these groups. I am not sure what else to say since I have never heard of either Coon or Brace.
Largely because you cannot distinguish subspecies when faced with clinal variation.
Hmm. It doesn't seem like heterozygosity is a good measure for genetic diversity outside of specific circumstances.
Q: How genetically diverse are humans?
It’s become a popular view that the human species is extraordinarily homogeneous genetically when compared to most other species.[15] This notion argues against the existence of human races, because very little genetic variation within the entire species means there cannot be much variation between major human populations. Before examining this further, we should first inquire about what is meant by ‘genetic diversity.’
Because little can be learned from a locus that is the same in every individual, the study of phylogenetics depends on polymorphic loci. Over the past few decades, methods have been developed that allow different kinds of these polymorphic ‘markers’ to be assayed in individuals. Prior to the 1990s, genetic diversity was usually inferred from classical (non-DNA) polymorphisms, such as blood groups, serum proteins, allozymes and immunoglobins. Later, restriction enzymes were employed to produce a useful class of marker at the DNA level, restriction fragment length polymorphisms (RFLPs). Other loci such as mitochondrial DNA (mtDNA), Alu insertions, minisatellites, single nucleotide polymorphisms (SNPs) and microsatellites (STRPs - short tandem repeat polymorphisms) have also been utilized for population genetic studies. Due to their high polymorphism, rapid mutation rate and random distribution throughout the genome, microsatellites are probably the most important class of marker in use today.[16] Highly variable loci are an advantage in phylogenetics because they can provide the finer resolution necessary for distinguishing closely related populations (such as subspecies).
The majority of population genetic studies over the past decade have investigated the various regions of mitochondrial DNA, a molecule that resides in the cytoplasm outside a cell’s nucleus. mtDNA contains 37 genes and is comprised of 16,569 base pairs in humans. Because it is haploid and maternally inherited, mtDNA has an effective population size about one-quarter that of the autosomes (the non-sex chromosomes). It’s easy to collect, has a relatively high mutation rate, and in particular, its lack of recombination allows for a straightforward assessment of the relationship between haplotypes. Lack of recombination also means that all parts of the molecule are completely linked, which prevents independent evolution of mtDNA’s 37 genes and non-coding control region. For this reason, mtDNA is considered a single genetic locus for phylogenetic purposes. Humans have relatively low mitochondrial diversity compared to the other great apes, and reports of this are mostly responsible for the belief that humans have low genetic diversity. However, mtDNA makes up just a few millionths of the human genome,[17] and as a single locus, carries little statistical weight.
When allele frequency data are used to estimate genetic diversity within a population, a frequently reported statistic is the average number of alleles per locus (A), but because rare alleles do not contribute much to overall diversity, the most informative statistic is average heterozygosity (H). This is estimated from both the number of alleles and the frequencies at which they occur, and is generally defined as the percentage of individuals in a population that are heterozygous (have two different alleles) at a random locus. In general, genetic diversity is synonymous with mean heterozygosity.
I think you mistraslated group selection. FWIW, it's almost universally rejected.
So how do you objectively ascertain someone's race?Actually not as much. That objection is only true for the formentioned reason that "race" have a history of a colloquial usage where it, unlike in biology, could denote even (at times exclusively) cultural groups with little or no consideration of descent.
Thanks, I'll get back to you on that later.'The History and Geography of Human Genes' (L. Luca Cavalli-Sforza, Paolo Menozzi, Alberto Piazza. 1994)
Thanks. I'll see if I can find those.The criteria formentioned is given in 'Principles of genealogical concordance in species concepts and biological taxonomy' (Avise JC, Ball RM. 1990) and 'Bureaucratic mischief: recognizing endangered species and subspecies' (O'Brien SJ, Mayr E. 1991)
I can't quite take that away. The biggest problem is that there is no consideration of the gradual, clinal change between human populations.Apart from arguments regarding how race isn't a social construct? It explains how it, as a term, is in accordance with biological classifications as opposed of being an arbitrary, non-biological term/concept. I thought that was, in part, what we were discussing.
I am somewhat confident now that what you think of as race does not exist among modern humans.We can, through genetic markers, identify which main groups they descended from. We can even find the supra and meta levels of ancestral population-groups. So, we end up with hobknobbing about the semantics of the terms to use to describe them.
To be precise: I mean observed heterozygosity.I tend to agree with the author that it is probably the most informative statistic regarding, in this context, subspecie diversities et al. I might be wrong about that, but I don't find much fault with the argument as he lays it out.
So how do you objectively ascertain someone's race?
Thanks, I'll get back to you on that later.
FWIW. Cavalli-Sforza considers the concept of race to be a "scientific failure"(his words).
Speaking about Cavalli-Sforza, it is interesting that he tried to defuse potential political attacks on his research by a simple and sometimes surprisingly effective rhetorical ploy. At one point he just stopped using the term ‘‘race’’ and replaced it with a much less loaded expression ‘‘human population’’, which in many contexts he actually used more or less with the same meaning as ‘‘race’’. On one occasion this terminological switch gave rise to an amusingly ironic development, as described in the following episode involving Cavalli-Sforza’s collaborator, Edwards:
'When in the 1960s I started working on the problem of reconstructing the
course of human evolution from data on the frequencies of blood-group genes
my colleague Luca Cavalli-Sforza and I sometimes unconsciously used the
word ‘race’ interchangeably with ‘population’ in our publications. In one
popular account, I wrote naturally of ‘the present races of man’. Quite recently I quoted the passage in an Italian publication, so it needed translating. Sensitive to the modern misgivings over the use of the word ‘race’, Cavalli-Sforza suggested I change it to ‘population’. At first I was reluctant to do so on the grounds that quotations should be accurate and not altered to meet contemporary sensibilities. But he pointed out that, as the original author, I was the only person who could possibly object. I changed ‘present races of man’ to ‘present populations of man’ and sent the paper to be translated into Italian. When it was published the translator had rendered the phrase as ‘le razze umane moderne’.
...
So, the whole process unfolded in three stages. First, it began with the original text containing the word ‘‘race’’. Then with time the term started to sound unacceptable or jarring to some people, and consequently the pressure of the new linguistic practice transformed it into ‘‘population’’. Finally, an easygoing and politically unconcerned Italian translator just went ahead and turned it back into ‘‘razza’’."
I can't quite take that away. The biggest problem is that there is no consideration of the gradual, clinal change between human populations.
Then also, it seems impossible to divide the human species into clades that approximate the popular races in any way.
I am somewhat confident now that what you think of as race does not exist among modern humans.
To be precise: I mean observed heterozygosity.
By genetic diversity, we mean how many different alleles a species has, right?
Now, all else equal, if a species practices a lot of inbreeding there will be more homozygous individuals, regardless of the number of alleles to chose from. So it seems to me that observed heterozygosity is not suited for comparing diversity across species.
After you've spent this thread so far trying to come up with theoretical reasons why the facts I've presented should theoretically not be as they are, that irony almost got you disqualified from even the bother of responding to you at all anymore, as your behavior at that point had gotten so flagrant and obvious there didn't seem to be much need to point it out after that.You don't come across as someone who cares about facts.
"Emphasis" and "major" do not exclude the existence of any other factors/forces at work and their effects on the present results. And I have already said myself just a few posts ago that a set of distinct ancestry-based groups can, and should be expected to, yield clines (or even complete re-convergence) some time later. I don't know how quickly or slowly to say they develop, but humans have had scores of millennia since the last major separating event(s). Both processes are a part of the complete story, and I'm already familiar with how our genomes show evidence of both, so the race denial case needs to show not just that clines do exist (because race non-deniers don't claim they don't), but that the racial allele clusters don't.They emphasize the role of clines of human genetic diversity and argue that "isolation-by-distance" is the major reason for genetic differences between geographic areas.
The race denial case doesn't need "small". It needs "zero". Otherwise, the case they're defending isn't "no such thing as races", but merely "races do exist (but make relatively little difference)", which I have not argued against.They argue that the clusters are real and due to barriers such as the oceans, the sahara and the himalayas. However, even so, they agree that the discontinuity brought about by these barriers is small.
I have briefly skimmed over the paper. The two things that stood out to me, when they were talking about the studies showing natural genetic clustering, were the straw men they used: claiming that just a few sample sites from far-flung extreme corners of the world were used, and acting as if anybody had ever said the Mediterranean Sea was supposed to be a genetic dividing line. The underwhelming level of honesty there is not encouraging.The main conclusion seems robust but the methodological debate is not over yet. Factors that influence the conclusion are sampling, assumptions going into the statistical methods and the number and nature of the "genes" being looked at.
I've skimmed over the relevant passages in the above cited book.By using the previously given phylogenetic criterias with regards to the more recent biogeographical groups marked through the genome project (which, again, incidentally, match up pretty close to the old racial groupings of the much lambasted Carleton Coon... as irony would have it perhaps?) I.e nasic hereditary breeds within a species whose geographical, genetic as well as historical isolations can account for their phylogenetic distances inbetween each other. In a much simpler, conventional way, we do the same with dog breeds et al.
Another misunderstanding. As far as I could tell so far, CS is very clear that his groupings reflect non-biological criteria.Yes, he is an avid opponent of the term 'race', yet he studies them and groups them practically in the fashion the race-anthropologists of old did. His usage of the term "population" is basically the same as the formentioned explaination of race.
Slandering the man's motives instead of addressing his arguments? Not impressed.For relevance and a bit curiosa, Sesardic wrote the following on Sforza's semantics:
Biology makes a distinction between a cline and a hybrid zone.Well that is mostly an issue if we think that overlaps, when they occur, negate the biological validity of the groups they overlap inbetween. The same issue could be said with regards to the breeds of dogs (which, in Sweden, aren't called "breeds" but "races"). If clinal change between human populations is not a social construct, nor our ability to detect and group the hubs gradience flows between, then race really isn't a social construct either.
What I was saying is that observed heterozygosity seems to me, not to be a good measure of genetic diversity.I really do not understand your criticism, unless we've somehow wandered into specie'ism? The relevance relates to genetic diversity, and it is an common claim that human beings are not and have not been diverse for enough long a time for there to exist races/subspecies (which is false). Therefore, it is interesting to know that, looking at distant as well as close mammalian relatives, racial classification is quite appliable to our specie.
I couldn't find the first source on the net but I guess that's not important.The issue is not that you can get any old group to fit any old category, as the requirement for them follow out of biological ancestry where a given population has evolved/developed in a specific geographic location, having phylogenetically phenotypic characters with which they share more closely to each other than with extra-groups in their surroundings due to genetic partitioning between them and... that the phylogenetic distribution follows through genetic traits in accordance with taxonomical conventions.
The criteria formentioned is given in 'Principles of genealogical concordance in species concepts and biological taxonomy' (Avise JC, Ball RM. 1990) and 'Bureaucratic mischief: recognizing endangered species and subspecies' (O'Brien SJ, Mayr E. 1991)
I'm thinking you're misremembering something.