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Title: Tajima's D Post by: Polymorphism on Oct 11, 2010 Is there any one value expected for tajima's D for a locus evolving under the neutral theory of evolution? If so, what is it and why?
I don't understand how a value is determined to be low enough to be suggestive of a natural selection. Is it absolute (for example any value under 0 suggests natural selection) or relative to other value of tajima's D for surrounding loci. Title: Re: Tajima's D Post by: bio_man on Oct 11, 2010 No, I think it varies depending on your data. For instance, a negative Tajima's D signifies an excess of low frequency polymorphisms, indicating population size expansion and/or positive selection. A positive Tajima's D signifies low levels of both low and high frequency polymorphisms, indicating a decrease in population size and/or balancing selection.
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