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Author | Topic: Human Races | ||||||||||||||||||||
Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
Hi crashfrog,
There is a dilema associated with eliminating distinctions among groups that has medical repercussions. In terms of politics/social issues, race should not be used. There is greater genetic variation within groups than among them rendering a biological concept of race in humans highly inaccurate. However, in addition to superficial characteristics such as skin color which can identify people as originating in one population versus another, there are also certain alleles at higher frequency in different populations than others for not so obvious traits. There is some evidence that this can have an impact on how people from specific ethnic groups will respond to medicines. This is an example where one does want to make a distinction between groups so as to provide the appropriate tests in determining say drug safety or efficacy. However, this should not be taken as a way of dividing "races" as has commonly been practiced.
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Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
Hi crashfrog,
I agree completely. The burden is on the scientific establishment to make this clear and comprehensible to the general public while at the same time showing that the original concept of race is meaningless. Thus far there has been a lot of ink and paper spent on the debunking of race but very little on providing a meaningful substitute. It's not so simple...you have seen on this site how few people understand genetics and race is a convenient way to maintain prejudice and control over people so it won't disappear even though it is in direct contradiction of the facts..kind of like creationism
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Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
Hi T,
quote: If a trait varies in the population, it is amenable to genetic analysis and there is probably someone studying it. Pigmentation differences are important for medically related work such as skin cancer so the basis of trait variance among groups is under study.
quote: However, race does not exist. There is more variation among Africans than between Africans and Europeans. So how can you look at a person and catagorize them as belonging to a race? And superficial characters like skin color are irrelevant. You can obtain a great dea of morphological difference without it having to rely on huge genetic differences for example morphotypes of artic char. Not to mention there has been gene flow among all of the different human groups blurring the lines even further.
quote: I agree. But race as a criteria is a hinderance. The existing differences have to be studied at the population level where ethnic differences (that can lead to isolation and hence show up in the genes) regional differences, environmental differences etc. can all be taken into account to give a more accurate result. That is why current human population studies are not just based on random sampling of a couple of "Asian" guys and europeans but are usually concerned with sampling multiple populations from different regions. cheers,M
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Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
Here are some references. Yes, Africa has the most diversity. According to the out of Africa hypothesis of human evolution, we originated in Africa, expanded and then migrated out to colonize the rest of the world. Though there must have been a great deal of migration in and out of Africa, the end effect is that colonized areas would show less genetic diversity than the original source population i.e. Africa should have more genetic variation among populations than say Europe for example
Genome Res. 2003 Jul;13(7):1607-18. Epub 2003 Jun 12. Related Articles, Links Genetic variation among world populations: inferences from 100 Alu insertion polymorphisms. Watkins WS, Rogers AR, Ostler CT, Wooding S, Bamshad MJ, Brassington AM, Carroll ML, Nguyen SV, Walker JA, Prasad BV, Reddy PG, Das PK, Batzer MA, Jorde LB. Department of Human Genetics, University of Utah, Salt Lake City, Utah 84112, USA. We examine the distribution and structure of human genetic diversity for 710 individuals representing 31 populations from Africa, East Asia, Europe, and India using 100 Alu insertion polymorphisms from all 22 autosomes. Alu diversity is highest in Africans (0.349) and lowest in Europeans (0.297). Alu insertion frequency is lowest in Africans (0.463) and higher in Indians (0.544), E. Asians (0.557), and Europeans (0.559). Large genetic distances are observed among African populations and between African and non-African populations. The root of a neighbor-joining network is located closest to the African populations. These findings are consistent with an African origin of modern humans and with a bottleneck effect in the human populations that left Africa to colonize the rest of the world. Genetic distances among all pairs of populations show a significant product-moment correlation with geographic distances (r = 0.69, P < 0.00001). F(ST), the proportion of genetic diversity attributable to population subdivision is 0.141 for Africans/E. Asians/Europeans, 0.047 for E. Asians/Indians/Europeans, and 0.090 for all 31 populations. Resampling analyses show that approximately 50 Alu polymorphisms are sufficient to obtain accurate and reliable genetic distance estimates. These analyses also demonstrate that markers with higher F(ST) values have greater resolving power and produce more consistent genetic distance estimates. Here is one example of migration showing a measureable effect in the gene pool Hum Biol. 2002 Oct;74(5):645-58. Related Articles, Links Y-chromosome analysis in Egypt suggests a genetic regional continuity in Northeastern Africa. Manni F, Leonardi P, Barakat A, Rouba H, Heyer E, Klintschar M, McElreavey K, Quintana-Murci L. Laboratoire d'Anthropologie Biologique (CNRS FRE 2292); Musee de l'Homme MNHN, Paris, France. The geographic location of Egypt, at the interface between North Africa, the Middle East, and southern Europe, prompted us to investigate the genetic diversity of this population and its relationship with neighboring populations. To assess the extent to which the modern Egyptian population reflects this intermediate geographic position, ten Unique Event Polymorphisms (UEPs), mapping to the nonrecombining portion of the Y chromosome, have been typed in 164 Y chromosomes from three North African populations. The analysis of these binary markers, which define 11 Y-chromosome lineages, were used to determine the haplogroup frequencies in Egyptians, Moroccan Arabs, and Moroccan Berbers and thereby define the Y-chromosome background in these regions. Pairwise comparisons with a set of 15 different populations from neighboring European, North African, and Middle Eastern populations and geographic analysis showed the absence of any significant genetic barrier in the eastern part of the Mediterranean area, suggesting that genetic variation and gene flow in this area follow the "isolation-by-distance" model. These results are in sharp contrast with the observation of a strong north-south genetic barrier in the western Mediterranean basin, defined by the Gibraltar Strait. Thus, the Y-chromosome gene pool in the modern Egyptian population reflects a mixture of European, Middle Eastern, and African characteristics, highlighting the importance of ancient and recent migration waves, followed by gene flow, in the region. and another worldwide study of human genetic diversity Am J Hum Genet. 2000 Mar;66(3):979-88. Related Articles, Links The distribution of human genetic diversity: a comparison of mitochondrial, autosomal, and Y-chromosome data. Jorde LB, Watkins WS, Bamshad MJ, Dixon ME, Ricker CE, Seielstad MT, Batzer MA. Department of Human Genetics, University of Utah Health Sciences Center, Salt lake City, UT, 84112, USA. lbj@genetics.utah.edu We report a comparison of worldwide genetic variation among 255 individuals by using autosomal, mitochondrial, and Y-chromosome polymorphisms. Variation is assessed by use of 30 autosomal restriction-site polymorphisms (RSPs), 60 autosomal short-tandem-repeat polymorphisms (STRPs), 13 Alu-insertion polymorphisms and one LINE-1 element, 611 bp of mitochondrial control-region sequence, and 10 Y-chromosome polymorphisms. Analysis of these data reveals substantial congruity among this diverse array of genetic systems. With the exception of the autosomal RSPs, in which an ascertainment bias exists, all systems show greater gene diversity in Africans than in either Europeans or Asians. Africans also have the largest total number of alleles, as well as the largest number of unique alleles, for most systems. GST values are 11%-18% for the autosomal systems and are two to three times higher for the mtDNA sequence and Y-chromosome RSPs. This difference is expected because of the lower effective population size of mtDNA and Y chromosomes. A lower value is seen for Y-chromosome STRs, reflecting a relative lack of continental population structure, as a result of rapid mutation and genetic drift. Africa has higher GST values than does either Europe or Asia for all systems except the Y-chromosome STRs and Alus. All systems except the Y-chromosome STRs show less variation between populations within continents than between continents. These results are reassuring in their consistency and offer broad support for an African origin of modern human populations. and here is a review dealing with human pop gen and the issue of race C R Acad Sci III. 1998 Jun;321(6):443-6. Related Articles, Links Human genome diversity. Cann HM. Fondation Jean-Dausset, Centre d'etude du polymorphisme humain (CEPH), Paris, France. howard.cann@cephb.fr Human genome diversity studies analyse genetic variation among individuals and between populations in order to understand the origins and evolution of anatomically modern humans (Homo sapiens sapiens). The availability of thousands of DNA polymorphisms (genetic markers) brings analytic power to these studies. Human genome diversity studies have clearly shown that the large part of genetic variability is due to differences among individuals within populations rather than to differences between populations, effectively discrediting a genetic basis of the concept of 'race'. Evidence from paleontology, archaeology and genetic diversity studies is quite consistent with an African origin of modern humans more than 100,000 years ago. The evidence favors migrations out of African as the source of the original peopling of Asia, Australia, Europe and Oceania. An international program for the scientific analysis of human genome diversity and of human evolution has been developed. The Human Genome Diversity Project (HGDP) aims to collect and preserve biologic samples from hundreds of populations throughout the world, make DNA from these samples available to scientists and distribute to the scientific community the results of DNA typing with hundreds of genetic markers.
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Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
quote: However, oranges and grapefruit are fruits of completely different species wherease Africans are not a different species from other Homo sapiens (at least I would hope you are not suggesting this). I would therefore not expect the genetic diversity of oranges and grapefruit plants to overlap extensively whereas different populations of humans should have overlapping variation though some traits could reach a high local frequency.
quote: If you can randomly sample two Africans, Chinese, aborigines, whatever and find greater differences between individuals than among populations that are geographically separated i.e. Europeans, then how do you propose to define race genetically in any meaningful way? How can such a concept be in anyway meaninful when it describes a smaller subset of the interindividual variation than exists within a population? It is a genetic concept of race that is not supported by the evidence.Even your Viking example does not stand up to scrutiny. All variable traits show a normal distribution of variants...so are you going to call natural variants of your Viking "race" who are short and have dark hair a different race? How about the !Kung bushmen of Africa...they don't look like the Masai on average..yet another race? I am sure they have some private polymorphisms or microsats that are at different frequencies in the population than fishermen in Hong Kong...does that make them a "race"? My mother is Spanish and my father is a mix of Welsh, German, and Russian...which "race" am I genetically? For that matter, find a "pure" population of anything. If you read basic genetics on the effects of migration on population genetic structure i.e. gene flow...you don't need complete replacement or invasion for homogenization or the spreading of alleles from one population to another and human populations have not been living in complete isolation for a very long time.
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Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
quote: I don't understand this logic at all. So if I want to find out what the genetic diversity is of a species, I should ignore populations that are separated? Which population should I sample then to determine what the variation is for the species? What is representative? and it is not only non-coding DNA that is studied...here is one review Annu Rev Genomics Hum Genet. 2003;4:293-340. Related Articles, Links Patterns of human genetic diversity: implications for human evolutionary history and disease. Tishkoff SA, Verrelli BC. Department of Biology, University of Maryland, College Park, Maryland 20742, USA. st130@umail.umd.edu Since the completion of the human genome sequencing project, the discovery and characterization of human genetic variation is a principal focus for future research. Comparative studies across ethnically diverse human populations and across human and nonhuman primate species is important for reconstructing human evolutionary history and for understanding the genetic basis of human disease. In this review, we summarize data on patterns of human genetic diversity and the evolutionary forces (mutation, genetic drift, migration, and selection) that have shaped these patterns of variation across both human populations and the genome. African population samples typically have higher levels of genetic diversity, a complex population substructure, and low levels of linkage disequilibrium (LD) relative to non-African populations. We discuss these differences and their implications for mapping disease genes and for understanding how population and genomic diversity have been important in the evolution, differentiation, and adaptation of humans. and here is one dealing with genetics and the sociological issues surrounding race Annu Rev Genomics Hum Genet. 2003;4:33-67. Related Articles, Links Race, ancestry, and genes: implications for defining disease risk. Kittles RA, Weiss KM. National Human Genome Center, Howard University, Washington, D.C. 20060, USA. rkittles@howard.edu Geneticists are interested in finding genes associated with disease. Because of widespread health disparities, race is a variable that is often said to be relevant in this context. The idea is that members of a preconceived "race" share common ancestry that may include genetic risk factors. Human variation has been shaped by the long-term processes of population history, and population samples that reflect that history carry statistical information about shared genetic variation or "ancestry." But race is an elusive concept and a term difficult even to define rigorously. Unfortunately, these problems are neither new nor related to recent genetic knowledge. Race is also one of the most politically charged subjects in American life because its associated sociocultural component has notoriously led to categorical treatment that has been misleading and politically misused. There are ways in which the concept of race (whether or not the term is used) can be a legitimate tool in the search for disease-associated genes. But in that context race reflects deeply confounded cultural as well as biological factors, and a careful distinction must be made between race as a statistical risk factor and causal genetic variables. Non-coding genes in any case, are highly useful in determining the genetic relationships both among and within groups with recent common ancestry (as opposed to more slowly evolving coding sequences). Thus, such loci are critical to establishing or refuting race as a valid biological concept.
quote: Why call this a race? I am sure I could distinguish the members of my family from you...does that make us part of a separate race? I have European mitochondrial DNA sequence (from my Spanish mother). My nuclear DNA will be a hodgepodge. Am I a different race from my parents? Particular genetic distinctions can be made between populations without having to resort to race since doing so forces you to basically define any new mutation as a new race (sounds like Syamsu).
quote: I would agree but I would not call this race.Here is the Websters definition...pay attention to the taxanomic defintion of race Main Entry: 3raceFunction: noun Etymology: Middle French, generation, from Old Italian razza Date: 1580 1 : a breeding stock of animals 2 a : a family, tribe, people, or nation belonging to the same stock b : a class or kind of people unified by community of interests, habits, or characteristics 3 a : an actually or potentially interbreeding group within a species; also : a taxonomic category (as a subspecies) representing such a group b : BREED c : a division of mankind possessing traits that are transmissible by descent and sufficient to characterize it as a distinct human type 4 obsolete : inherited temperament or disposition 5 : distinctive flavor, taste, or strength (as a subspecies)...there are no human subspecies. Race is to great a distinction for comparsion of human populations when our closest relative the chimp has overall over 4 fold higher genetic diversity in only a fraction of the population size as the entire human species.
quote: Regarding the japanese...the barriers are leaky as they have a strong genetic connection with the Koreans. J Hum Genet. 1999;44(4):240-5. Related Articles, Links Genetic variations on the Y chromosome in the Japanese population and implications for modern human Y chromosome lineage. Shinka T, Tomita K, Toda T, Kotliarova SE, Lee J, Kuroki Y, Jin DK, Tokunaga K, Nakamura H, Nakahori Y. Department of Public Health, School of Medicine, University of Tokushima, Japan. A polymorphism in the coding sequence of the SRY gene was found by single-strand conformation polymorphism (SSCP) and direct sequencing analysis. The new allele of the SRY gene, which is raised by a C-to-T transition in the 155th codon, was found in 24% of Honshu, 35% of Okinawan, and 51% of Korean males respectively, whereas it was not observed among 16 Caucasian and 18 Negroid males. A haplotype analysis of the Y chromosome was carried out in Japanese, Korean, Caucasian and Negroid populations, using a combination of the polymorphisms in SRY, DXYS5Y, DYS287, and DXYS241Y loci. The results indicated that the Y chromosomes can be classified into seven heplotypes (Ia, Ib, Ic, IIa, IIb, III, IV). However, of these seven, only four (Ia, IIa, III, IV) were observed in the Japanese population. Furthermore, the presumed haplotype C, Y1, YAP, (CA)14, from which haplotype III was probably derived, was not found in any populations in this study. The regional distribution of each haplotype revealed that type III is more frequently observed in Okinawa (16%) and in Korea (21%) than in Honshu (4.4%). The haplotype analysis of the Y chromosome may contribute to the exploration of the origin of Japanese and the relationship between east Asian populations. here is another reference : Am J Hum Genet. 1995 Apr;56(4):951-62. Related Articles, Links Erratum in:Am J Hum Genet 1995 Jun;56(6):1512. Y chromosomal DNA variation and the peopling of Japan. Hammer MF, Horai S. Laboratory of Molecular Systematics and Evolution, University of Arizona, Tucson 85721, USA. Four loci mapping to the nonrecombining portion of the Y chromosome were genotyped in Japanese populations from Okinawa, the southernmost island of Japan; Shizuoka and Aomori on the main island of Honshu; and a small sample of Taiwanese. The Y Alu polymorphic (YAP) element is present in 42% of the Japanese and absent in the Taiwanese, confirming the irregular distribution of this polymorphism in Asia. Data from the four loci were used to determine genetic distances among populations, construct Y chromosome haplotypes, and estimate the degree of genetic diversity in each population and on different Y chromosome haplotypes. Evolutionary analysis of Y haplotypes suggests that polymorphisms at the YAP (DYS287) and DXYS5Y loci originated a single time, whereas restriction patterns at the DYS1 locus and microsatellite alleles at the DYS19 locus arose more than once. Genetic distance analysis indicated that the Okinawans are differentiated from Japanese living on Honshu. The data support the hypotheses that modern Japanese populations have resulted from distinctive genetic contributions involving the ancient Jomon people and Yayoi immigrants from Korea or mainland China, with Okinawans experiencing the least amount of admixture with the Yayoi. It is suggested that YAP+ chromosomes migrated to Japan with the Jomon people > 10,000 years ago and that a large infusion of YAP- chromosomes entered Japan with the Yayoi migration starting 2,300 years ago. Different degrees of genetic diversity carried by these two ancient chromosomal lineages may be explained by the different life-styles (hunter-gatherer versus agriculturalist). of the migrant groups, the size of the founding populations, and the antiquities of the founding events. Regarding how to treat people, I am not arguing about that or accusing you. My issue in this thread is the utility of race as a biological concept and I find it to be completely useless.
quote: My point is that the overlap among populations is enormous. If you look at the genetic diversity distributions of humans they overlap even if some alleles are locally at higher frequency than in other places. Geneticists, evolutionary biologists, or forensics specialists are forced to use population measures of diverstiy as opposed to race measures. Given the implication of race as a much greater genetic distance between groups (subspecies) I do not see any support for this in any study of human genetic diversity and thus find it unhelpful as a concept. I am not claiming that one should ignore differences among groups and this is not the case. Why do you think those studying genetic disease look for isolated populations of people like the Amish? It makes mapping genes easier. But I would not call the Amish a race.
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Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
quote: So how is this useful biologically? The color provides no information about any other charactertic of the population so what do I use it for? How about this, Ashkenazi jewish women have a high frequency of BRCA1 mutation and hence a higher than average chance of developing breast cancer. One can, and it has been done, study this group to identify the molecular aspects contributing to breast cancer...all without involving "race" while still ackowledging a characteristic of a specific population and its unique history.
quote: You do realize that genetic mapping involves typing neutral non-coding loci that have nothing to do with actual genes? individual, within group, within and among population differences are not measured by examining non-varying loci. What you are basically stateing here is that because population genetics is based on variable loci that may or may not have to do with a trait one is interested in, such studies are invalid. Population separation, cultural practices etc. have a direct impact on the population genetics of the group and thus non-coding DNA is the first to exhibit such an impact and thus it is the only way to measure differences between groups.
quote: that you define it as "race in some sense" suggests that it is such a fuzzy concept that it is not useful.
quote: I targetted the biological definition as opposed to the cultural since we are talking about whether or not a genetic basis for human race is valid. I exclude definition 1 since there are no breeding stocks of humans. The biological definition refers to a subspecies level distinction among groups for which there is no evidence from human genetics. The second defintion is cultural and I find irrelevant to finding out if there is a biological basis to race...just because someone associates with a group or culture does not mean that their genetics bears out this association.
quote: Because several of the haplotypes common among Japanese are common among other Asian populations. If you had an unmarked sample of blood and typed it genetically you could not say to what "race" it came from. The only differences are the frequency of known alleles as opposed to clear cut lines demarcating alleles that exist in one population and are completely absent in the others like you would expect if there were true distinct "race/subspecies" of humans.
quote: No, we do not know a priori that we are all humans even from morphology. It was not known that forrest elephants in Africa (L.cyclotis) were almost as distinct from savannah elephants (L. africana) as they are from Asian elephants (a different genus) until the genetics was done. If allele frequencies among human groups overlap extensively then regardless of the outliers in the distribution, you cannot subdivide the species into separate races.
quote: It would not as there is not enough to genetically distinguish the Amish from any other human group to warrant a sub-species definition. But since you say race does not mean sub-species...what do you then biologically equate with race?
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Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
quote: So the fact that Africa taken combined demonstrates the greatest genetic diversity (not to mention that most phylogenetic/pop gen studies based on this diversity point to Africa as the source of Homo sapiens) is meaningless? Unless you are channeling Syamsu I do not see how comparison among groups of populations of ONE SPECIES is meaningless. How would you know the relative frequency of anything just looking at one population?
quote: Exactly, however, they are not part of a "race" and if I had assumed they were just of the "jewish race" then I would not have the information about the specific population in the first place and those providing treatment would not be informed. This is another reason why race is a useless concept.
quote: Ok Peter, then by you logic, we can only use genes that are coding and unlikely to vary within the human species or are likely to show converging mutations due to selective constrainst on proteins..there goes your biological race definition since we will all be identical. I guess you also are willing to testify in court that forensic work based on neutral markers for DNA typing are invalid since they are non-coding sequences?
quote: Citations please that indicate that this is true..find me a "racial" sequence that separates north Africans from all other humans on the planet. Good luck, the data do not support you.
quote: You have to make up your mind. Just conflating all the different definintions makes race even more useless. Yes, species are fuzzy so you want to therefore claim there is a precise definition for a concept (race) several orders of magnitude more difficult to reconcile for which there is data that is contradictory to such a proposition.
quote: Good luck catcihg the perpetrator, identifiying the individual, etc. if "narrowing it down" for you means Japan, North and South Korea, parts of China, and Taiwan. Not exactly useful forensically.
quote: Because breeding of domestic cats is by artificial selection that prevents genotypes from interacting with each other to suit a particular taste. Outside of slavery, this has never been the case with humans who experience enough gene flow (and have throughout their history) that alleles you find in Native Americans you will find in South Africans.
quote: Show me an example of a genetically determined trait that is uniquely bound in a human-subpopulation. Actually, show me those traits that overlap with "race" that are genetically determined via citation. I only come across counter examples with very leaky boundaries making the concept useless.
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Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
quote: Then you are operating under an interpretation of the definition of "race" that is not widely shared (as WK pointed out) and are using a word that has other connotations than what you wish to ascribe to it. Better to dump it and all its baggage and move on to something that is biologically relevant.
quote: And maybe if you but !Kung bushmen on a colony on Mars for 500,000 yeras alone and came back they would have diverged to the point that a concept of a separate "race" or even subspecies would be appropriate. But that is not our current reality. I am still waiting for your example of an exclusive genetic trait that partitions along the lines of "race". Not something that varies among and within populations (since you claim this is irrelevant) but what genes do the Japanese have that a central european does not or vice versa? This is what is required by your own defintion of race in several of your posts, you claim the genetic data support this, yet I don't find that to be the case. I find that some alleles for the genes studied thus far tend to vary in frequency among different populations and some groups have higher numbers of alleles i.e. Africa as a whole. But a true genetic feature that you can map perfectly to "race"?
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Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
quote: As do other non-Japanese Asians...not to mention the japanese that do synthesize ADH. So this hardly separates out a japanese race from Asians or europeans for that matter.
quote: For there to be genetic traits that coincide with distinct races there would have to be more divergence than there is scene since all you get is a blur of alleles between groups with some more frequent in one population than another but not able to distinguish one from another.
quote: Epigenetics in this case is irrelevant to the race issue. By that definition you are a race since epigenetic profiles are subject to more variation and chance events during development than transmission of DNA from parent to offspring. In any case, while a lot may not be known, there is certainly no data appearing in favor of your idea of genetic traits separating "races" from one another. And it is a bit to extreme to offhandedly dismiss the hundreds of studies of human population genetics that have been done.
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Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
How does it support what you are saying i.e. that there are genetic features unique to a given "race" if as you say it is "muddled" by all the interbreeding among humans? It hardly then argues that any unique "racial" features exist genetically to the point that it is a useful concept.
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Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
quote: Bad example. Mules are sterile and thus there is a species level separation at the F1 generation. No such barrier exists for ANY group of humans.
quote: This is done without recouse to "race". It is called population genetics and it will often not coincide with the cultural distinctions of "race".
quote: Again, the chances of finding a match or a demographic depend on the local population sampling and database, which will not superimpose on "race"
quote: And such studies are conducted and have produced useful information for both the medical and forensic fields..but have not produced a genetic "race" determinant.
quote: I don't see how this is relevant. One could breed humans that look like chihuahua's via artificial selection over many generations. All it says is that there is natural genetic and morphological variation in the species that can be selected for. Hardly any population on the planet that does not show this characteristic.
quote: Please show me a unique trait set of the "races" as you see them from the studies that have been cited in this thread. I think you will find it really difficult. Your family has a unique trait set..is the "Peter" family a race? I am genetically distinct from every living human on the planet..am I a race?
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Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
quote: considering they don't even have the same number of chromosomes and are different species I don't see your argument. I am not arguing that species don't exist and that there are not populations that are clearly distinct. I am arguing that different groups of humans are not this distinct.
quote: If I have a sample that yields a microsatellite pattern common among Nigerians (for the sake of argument) and it is found out that the sample came from a Nigerian then you have a match. Then you are stuck with all the cases where you get such a result and it does not come from a Nigerian. If humans were as different as species you would never get the eqivalent of say an Elephas maximus sequence from a Loxodonta africana sample.
quote: Um, and this is relevant how? Nobody could have imagined the phenotypes of dog breeds but it did not take much time to develope phenotype according to taste. How is this relevant to race?
quote: So as you march along Africa and suddenly people in Camaroon are more different from people in Iceland how do you say who belongs to what race? And note you bolded "conventional geographic" defintion of race whereas before you were using phenotype and cultural definitions of race.
quote: But even you have not given a consistent defintion of "race" so how is it useful? A genetic compenent of what we call "race" when the definition is sometimes socio-cultural, sometimes geographical, sometimes genetic....this is like arguing about what a "kind" means. All I get from the data is that the farther apart two populations are in H. sapiens the greater the genetic distance among alleles,the greater the difference in allele frequencies, and tremendous overlap regardless of what the social concepts of "race" claim.
quote: You clearly do not agree. You seem to think I should be able to go into the lab right now determine exactly what "race" any unmarked sample of blood belongs to. I would like to know exactly how and based on what. I have an Egyptian blood sample, a South African, a sample from New York, one from Paris, one from Munich, and mine...can I tell what race every one of these samples are genetically according to your criteria of "race" and what is a "race" to you. You have said it in the past but it has not been a fixed definition and since you brought up the mule example I tend to think you mean a rather large distinction among groups.
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Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
quote: No and if I can get the link to work I will show you why below. But in summary, the two are not comparable. You have an interbreeding population or intermixing group of populations of the same species with humans versus horses and donkeys which are not interbreeding populations and are F1 infertile.
quote: Except that their parents and their parents parents etc etc. have been interbreeding for thousands of years so that you can no better say what "race" your parents are than you can say what "race" you are.
quote: So you would agree that a white South African who is as genetically distinct from a Nigerian as a black South African is from the same Nigerian belong to the same race. Which African "race" would that be considering that their are Africans that differ from each other more than they differ from non-Africans?
quote: Re: the first is a strawman. If I put a group of humans on the moon for many generations I could end up with a different species and I am not arguing that humans could not form sub-species or fully separate species over time...just that Homo sapiens has not and is tending to homogenize rather than diverge. RE: the second, considering the immense amount of interaction among and between populations historically, you have such a muddled mess I don't see where you are going to find your nice distinct categories.
quote: Actually, if the distinctions between groups merited "race" designation you would not expect tremendous overlap...lets see if this works below
If this worked, you will see that of the over 1000 human comparisons you get a hump. If you have a real genetic difference between groups you see that the pairwise comparisons separate out from one another i.e. chimps do not overlap with humans at all. (The neandertal is sort of irrelevant in this case since it is a single sample against thousands). Looking at the human distribution could you please identifiy for me where the japanese are?
quote: Is that enough to conclude race? I could find genetic markers that make YOU different from everyone else to..are you a race?
quote: I actually would not care if race was a true biological distinction. But that a fairy poorly defined concept bordering on "kinds" and that is used to distinguish people is trying to gain credibility by claiming it has a clear genetic basis. If I just say that Africans are all one race so I can just pick any African from anywhere for my next clinical study I will probably end up with a drug that is deadly or useless. Biological terms should have at least a high probability of being relevant or real to be applied and race is so blurry it makes defining species look like a cake walk.
quote: I think that most people identify heavily with social concepts of race at some level...hell, even Basque nationalists are constantly trying to prove they are a superior native Iberian "race". So I think it has a little more impact on peoples lives than pondering quantum physics.
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Mammuthus Member (Idle past 6495 days) Posts: 3085 From: Munich, Germany Joined: |
quote: I'm sorry Peter but if you accept this then you should be comfortable with "kinds". You have shifted from defining race from lineages, to cultural associations, from saying Africans, Asians, Europeans are races to now saying Africa is too big and diverse to be a race. So I can call a "race" anything I want to and since individuals are not identical I am going to say every single human on the planet (assuming Clonaid has been unsuccessful) is genetically unique and is a race. And then tomorrow I will say that actually only the people in Grenwich Village on Tuesday nights are a race because I could find genetic support that the genetic constitution of that group may differ slightly from the constitution on Saturday nights. Is this really a useful concept? Considering the genetic distance graph I provided shows NO discernable distinction between different groups of humans the way it does for Neandertals, chimps or slime molds, I see no use in making a grossly exaggerated distinction among humans like "race". That humans have the potential to form races, species, genera, etc. given time, mutation, and selection is not at issue. At issue is whether this has occurred enough in the past to have separated us into distinct enough groups that could have been on potential trajectories toward speciation. I see no support for this. In fact we are one of the most genetically homogenous species of apes compared to chimps, gorillas and orang-utans. If you want to believe that the distinction between someone from Beijing is as different from a South African as a mountain gorilla from lowland gorilla then please show me the support. Considering virtually all data accumulated thus far points to an African origin (that is relatively recent) for modern humans, rather than races, every population outside of Africa is just an African sub-population if you want to cling to distinctions...and since relative to Africa, genetic diversity is much lower..we of european descent are just the leftover genetic post bottleneck dregs [This message has been edited by Mammuthus, 11-20-2003] [This message has been edited by Mammuthus, 11-20-2003]
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