Heckman Kellie L, Rasoazanabary Emilienne, Machlin Erica, Godfrey Laurie R, Yoder Anne D
Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06511 USA.
BMC Evol Biol. 2006 Nov 16;6:98. doi: 10.1186/1471-2148-6-98.
The past decade has seen a remarkable increase in the number of recognized mouse lemur species (genus Microcebus). As recently as 1994, only two species of mouse lemur were recognized according to the rules of zoological nomenclature. That number has now climbed to as many as fifteen proposed species. Indeed, increases in recognized species diversity have also characterized other nocturnal primates--galagos, sportive lemurs, and tarsiers. Presumably, the movement relates more to a previous lack of information than it does to any recent proclivity for taxonomic splitting. Due to their nocturnal habits, one can hypothesize that mouse lemurs will show only minimal variation in pelage coloration as such variation should be inconsequential for the purposes of mate and/or species recognition. Even so, current species descriptions for nocturnal strepsirrhines place a good deal of emphasis on relatively fine distinctions in pelage coloration.
Here, we report results from a multi-year study of mouse lemur populations from Beza Mahafaly in southern Madagascar. On the basis of morphological and pelage variation, we initially hypothesized the presence of up to three species of mouse lemurs occurring sympatrically at this locality, one of which appeared to be undescribed. Genetic analysis reveals definitively, however, that all three color morphs belong to a single recognized species, Microcebus griseorufus. Indeed, in some cases, the three color morphs can be characterized by identical mitochondrial haplotypes.
Given these results, we conclude that investigators should always proceed with caution when using a single data source to identify novel species. A synthetic approach that combines morphological, genetic, geographic, and ecological data is most likely to reveal the true nature of species diversity.
在过去十年中，已被确认的小鼠狐猴物种（Microcebus属）数量显著增加。就在1994年，根据动物命名规则，仅确认了两种小鼠狐猴。如今，这一数量已攀升至多达15个提议物种。事实上，其他夜行性灵长类动物——婴猴、嬉猴和跗猴的已确认物种多样性也有所增加。据推测，这种变化更多地与先前信息不足有关，而非近期对分类划分的偏好。由于它们的夜行习性，可以假设小鼠狐猴的毛色变化极小，因为这种变化对于配偶识别和/或物种识别而言应该无关紧要。即便如此，目前对夜行性原猴亚目的物种描述非常强调毛色的细微差别。
在此，我们报告了对马达加斯加南部贝扎马哈法利地区小鼠狐猴种群进行的多年研究结果。基于形态学和毛色变化，我们最初假设在该地区同时存在多达三种小鼠狐猴，其中一种似乎尚未被描述。然而，遗传分析明确显示，所有三种毛色形态都属于单一已确认物种——灰红小鼠狐猴（Microcebus griseorufus）。实际上，在某些情况下，这三种毛色形态可由相同的线粒体单倍型来表征。
鉴于这些结果，我们得出结论，研究人员在使用单一数据源识别新物种时应始终谨慎行事。结合形态学、遗传学、地理和生态数据的综合方法最有可能揭示物种多样性的真实本质。
