Zoological Museum, University of Hamburg, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany.
Evolution. 2011 Apr;65(4):923-31. doi: 10.1111/j.1558-5646.2011.01231.x. Epub 2011 Feb 15.
New insights in the speciation process and the nature of "species" that accumulated in the past decade demand adjustments of the species concept. The standing of some of the most broadly accepted or most innovative species concepts in the light of the growing evidence that reproductive barriers are semipermeable to gene flow, that species can differentiate despite ongoing interbreeding, that a single species can originate polyphyletically by parallel evolution, and that uniparental organisms are organised in units that resemble species of biparental organisms is discussed. As a synthesis of ideas in existing concepts and the new insights, a generalization of the genic concept is proposed that defines species as groups of individuals that are reciprocally characterized by features that would have negative fitness effects in other groups and that cannot be regularly exchanged between groups upon contact. The benefits of this differential fitness species concept are that it classifies groups that keep differentiated and keep on differentiating despite interbreeding as species, that it is not restricted to specific mutations or mechanisms causing speciation, and that it can be applied to the whole spectrum of organisms from uni- to biparentals.
在过去十年中积累的关于物种形成过程和“物种”本质的新见解，要求对物种概念进行调整。鉴于越来越多的证据表明生殖隔离对基因流动具有半透性，尽管存在持续的杂交，物种仍然可以分化，一个物种可以通过平行进化多起源，以及单倍体生物是由类似于二倍体生物物种的单位组织的，本文讨论了一些最广泛接受或最具创新性的物种概念的地位。作为现有概念和新见解的综合，提出了一个广义的基因概念，将物种定义为相互具有特征的个体群体，这些特征在其他群体中会产生负面的适合度效应，并且在接触时不能在群体之间经常交换。这种差异适合度物种概念的好处是，它将保持分化并继续分化的群体分类为物种，不受特定突变或导致物种形成的机制的限制，并且可以应用于从单倍体到二倍体的整个生物谱。
