Greig Duncan, Louis Edward J, Borts Rhona H, Travisano Michael
The Galton Laboratory, Department of Biology, University College London, Gower Street, London WC1E 6BT, UK.
Science. 2002 Nov 29;298(5599):1773-5. doi: 10.1126/science.1076374.
Most models of speciation require gradual change and geographic or ecological isolation for new species to arise. Homoploid hybrid speciation occurred readily between Saccharomyces cerevisiae and Saccharomyces paradoxus. Hybrids had high self-fertility (about 82%), low fertility when backcrossed to either parental species (about 7.5%), and vigorous growth under different thermal environments that favored one or the other of the parental species. Extensive karyotypic changes (tetrasomy) were observed in the hybrids, although genic incompatibilities accounted for 50% of the variation in self-fertility.
大多数物种形成模型都要求新物种的出现需要渐进变化以及地理或生态隔离。同倍体杂交物种形成在酿酒酵母和奇异酵母之间很容易发生。杂种具有较高的自育性（约82%），与任一亲本物种回交时育性较低（约7.5%），并且在有利于其中一个亲本物种的不同热环境下生长旺盛。在杂种中观察到广泛的核型变化（四体性），尽管基因不相容性占自育性变异的50%。
