ancient structure
Durand EY, Patterson N, Reich D & Slatkin M 2011 Testing for ancient admixture between closely related populations. Mol Biol Evol 28:2239-2252.
- D statistics do not allow us to distinguish between the models of admixture and ancestral subdivision
- ancestral subdivision and admixture can produce the same expected coalescence time between two individuals from different populations
- it is known that ancestral population subdivision results in a higher than expected variance in coalescence times
- ancestral subdivision is likely to result in more variation in gene tree depth when using several samples from the extant population
- this in turn will affect the site frequency spectrum of the extant population
- designing a statistic to distinguish between the two scenarios will require using more than one sample per population
