Fertility is not a function of geographic distance in Tetrahymena.
The fertility of crosses between wild stocks of Tetrahymena americanis (n = 93) and T. hegewischi (n = 52) was not significantly related to the square root of the distance separating the parental stocks. Much of the death was probably caused by age-related damage to the micronucleus. Despite the confounding age-related death, the conclusion that neither species has detectably isolated local populations is supported.
D000818:Animals; D004463:Ecology; D004777:Environment; D006824:Hybridization, Genetic; D013045:Species Specificity; D013768:Tetrahymena / Q000235:genetics*