Science. 1992 Apr 10;256(5054):193-7. doi: 10.1126/science.256.5054.193.
Hybridization, the interbreeding of species, provides favorable conditions for major and rapid evolution to occur. In birds it is widespread. Approximately one in ten species is known to hybridize, and the true global incidence is likely to be much higher. A longitudinal study of Darwin's finch populations on a Galápagos island shows that hybrids exhibit higher fitness than the parental species over several years. Hybrids may be at an occasional disadvantage for ecological rather than genetic reasons in this climatically fluctuating environment. Hybridization presents challenges to the reconstruction of phylogenies, formulation of biological species concepts and definitions, and the practice of biological conservation.
杂交,即物种间的杂交,为主要和快速进化提供了有利条件。在鸟类中,杂交现象非常普遍。已知大约每十个物种中就有一个会杂交,而实际的全球发生率可能更高。对加拉帕戈斯群岛上达尔文雀种群的纵向研究表明,在几年的时间里,杂种的适应性比亲本物种更高。在这种气候波动的环境中,杂种可能偶尔会因为生态而非遗传原因而处于劣势。杂交现象给系统发育的重建、生物物种概念和定义的制定以及生物保护的实践带来了挑战。