Could early gene flow have created similar allozyme-gene frequencies in cultivated and wild barley?

The possible role of early gene flow between wild and cultivated barley in their similar esterase gene frequencies was tested in a simulation study. T he hypothetical population consisted of 99.9% wild forms possessing three a lleles of an esterase gene and 0.01% domesticated forms possessing one of t hese esterase alleles. Various rates of inbreeding, selection coefficients against the wild form and shifting cultivation methods were tested for thei r effect on the establishment of the domesticated form and the esterase gen e flow between the two barley types. Of these factors, inbreeding rates, in the range of 90-99%, had the smallest effect on the establishment of the d omesticated form under primitive cultivation. Via gene flow, the esterase a llelic frequency in the domesticated form could be similar to that of the w ild form under 90% outcrossing in the domesticated form for 115-230 years, an unrealistic situation for barley which normally exhibits about 1% outcro ssing. It seems, therefore, that the similar esterase allelic frequencies i n wild and cultivated barley is only partly due to gene flow, and it is mor e plausibly accounted for by multiple domestications.