Table 1 Parallels between the X-chromosomal hybrid-isolation admixture model of Goldberg and Rosenberg (2015) and a breeding-system model of Jennings (1916)
Model featureAdmixture modelBreeding-system model
The initial “cross”An admixed population is formed by females from source population 1 and males from source population 2A cross occurs between a female AA and a male aY
Type of mating after the initial crossRandom mating occurs in the admixed populationRandom mating occurs among the progeny
No. generations of mating after the initial crossn − 1n − 1
Description of the population of interestAdmixed population under hybrid isolationInbred line
Quantities computed for the populationExpected X-chromosomal admixture proportion from source population 1 in the admixed population in generation n, in females (pn,f) and males (pn,m)Frequency of X-chromosomal allele A in the inbred line in generation n, in females (pn,f) and males (pn,m)
Mathematical resultsapn,f = Jn+1/2npn,f = Jn+1/2n
pn,m = Jn/2n−1pn,m = Jn/2n−1
SourceGoldberg and Rosenberg (2015, equations 12 and 13)Jennings (1916, paragraph 58)
  • a Jn represents entry n in the Jacobsthal number sequence.