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**mr.videomen** · 05-08-2010, 08:13 AM

2) Race is a scientific topic and is definable through analysis of the genome.
3) Two people from the same race are more related, genetically, than two people from different races.

http://www.ncbi.nlm.nih.gov/pmc/arti...0/?tool=pubmed

DISCUSSIONS of genetic differences between major human populations have long been dominated by two facts: (a) Such differences account for only a small fraction of variance in allele frequencies, but nonetheless (b) multilocus statistics assign most individuals to the correct population. This is widely understood to reflect the increased discriminatory power of multilocus statistics. Yet Bamshad et al. (2004) showed, using multilocus statistics and nearly 400 polymorphic loci, that (c) pairs of individuals from different populations are often more similar than pairs from the same population. If multilocus statistics are so powerful, then how are we to understand this finding?

In what follows, we use several collections of loci genotyped in various human populations to examine the relationship between claims a, b, and c above. These data sets vary in the numbers of polymorphic loci genotyped, population sampling strategies, polymorphism ascertainment methods, and average allele frequencies. To assess claim c, we define ω as the frequency with which a pair of individuals from different populations is genetically more similar than a pair from the same population. We show that claim c, the observation of high ω, holds with small collections of loci. It holds even with hundreds of loci, especially if the populations sampled have not been isolated from each other for long. It breaks down, however, with data sets comprising thousands of loci genotyped in geographically distinct populations: In such cases, ω becomes zero. Classification methods similarly yield high error rates with few loci and almost no errors with thousands of loci. Unlike ω, however, classification statistics make use of aggregate properties of populations, so they can approach 100% accuracy with as few as 100 loci.

05-08-2010, 08:13 AM	#10
mr.videomen Join Date Oct 2005 Posts 408 Senior Member	2) Race is a scientific topic and is definable through analysis of the genome. 3) Two people from the same race are more related, genetically, than two people from different races. http://www.ncbi.nlm.nih.gov/pmc/arti...0/?tool=pubmed DISCUSSIONS of genetic differences between major human populations have long been dominated by two facts: (a) Such differences account for only a small fraction of variance in allele frequencies, but nonetheless (b) multilocus statistics assign most individuals to the correct population. This is widely understood to reflect the increased discriminatory power of multilocus statistics. Yet Bamshad et al. (2004) showed, using multilocus statistics and nearly 400 polymorphic loci, that (c) pairs of individuals from different populations are often more similar than pairs from the same population. If multilocus statistics are so powerful, then how are we to understand this finding? In what follows, we use several collections of loci genotyped in various human populations to examine the relationship between claims a, b, and c above. These data sets vary in the numbers of polymorphic loci genotyped, population sampling strategies, polymorphism ascertainment methods, and average allele frequencies. To assess claim c, we define ω as the frequency with which a pair of individuals from different populations is genetically more similar than a pair from the same population. We show that claim c, the observation of high ω, holds with small collections of loci. It holds even with hundreds of loci, especially if the populations sampled have not been isolated from each other for long. It breaks down, however, with data sets comprising thousands of loci genotyped in geographically distinct populations: In such cases, ω becomes zero. Classification methods similarly yield high error rates with few loci and almost no errors with thousands of loci. Unlike ω, however, classification statistics make use of aggregate properties of populations, so they can approach 100% accuracy with as few as 100 loci.
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