Hoelzel A R
Department of Genetics, Cambridge University, UK.
Mol Ecol. 1992 Aug;1(2):119-25. doi: 10.1111/j.1365-294x.1992.tb00163.x.
Whales and dolphins (cetaceans) are found in all the world's oceans and in some of the major rivers, yet little is known about the distribution and behaviour of many species. At the same time, cetaceans are under threat from a variety of pressures including direct and indirect takes, pollution, and competition for habitat and prey. To ensure their long-term survival it will be necessary to preserve genetic diversity through the identification and protection of differentiated populations, the assessment of variation within local populations, and through a better understanding of reproductive and dispersal behaviour. The application of molecular genetic techniques is helping to provide answers to some of these previously intractable questions. Early results suggest few consistent patterns. Obvious geographic boundaries correlate to genetic distance in some species, and not in others. Furthermore, morphological variation within species can be fairly extensive without correlating to genetic distance, or relatively minor between morphotypes that are as genetically distinct as some species. These examples emphasize the need for further study.
鲸鱼和海豚（鲸目动物）分布于世界各大洋以及一些主要河流中，但人们对许多物种的分布和行为却知之甚少。与此同时，鲸目动物面临着各种压力的威胁，包括直接和间接的捕杀、污染以及对栖息地和猎物的竞争。为确保它们的长期生存，有必要通过识别和保护不同的种群、评估当地种群内部的变异以及更好地了解繁殖和扩散行为来保护遗传多样性。分子遗传技术的应用有助于为一些以前难以解决的问题提供答案。早期结果显示出的一致模式很少。在某些物种中，明显的地理界限与遗传距离相关，而在其他物种中则不然。此外，物种内部的形态变异可能相当广泛，但与遗传距离无关，或者在遗传上像某些物种一样不同的形态型之间变异相对较小。这些例子强调了进一步研究的必要性。
