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The taxonomic history of lemurs dates back to 1758 when Carl Linnaeus first classified them, and the taxonomy remains controversial today, with approximately 70 to 100 species and subspecies recognized, depending on how the term "species" is defined. Having undergone their own independent evolution on Madagascar, lemurs have diversified to fill many niches normally filled by other types of mammals. They include the smallest primates in the world, and once included some of the largest. Since the arrival of humans approximately 2,000 years ago, lemurs have become restricted to 10% of the island, or approximately , and many face extinction. Concerns over lemur conservation have affected lemur taxonomy, since distinct species receive increased conservation attention compared to subspecies. The relationship between the aye-aye and the rest of the lemurs has had the greatest impact on lemur taxonomy at the family rank and above. Genetic analysis of this relationship has also clarified lemur phylogeny and supports the hypothesis that lemurs rafted to Madagascar. Despite general agreement on phylogeny, the taxonomy is still under debate. At the genus level, the taxonomy has been relatively stable since 1931, but a number of additional genera have been recognized since then. Since the 1990s, there has been a steep increase in the number of recognized lemur species and subspecies through the discovery of new species, the elevation of existing subspecies to full species status, and the recognition of new species among previously known populations that were not even distinct subspecies. Currently living lemur species are divided into five families and 15 genera. If the extinct subfossil lemurs are included, three families, eight genera, and 17 species would be added to the count. The recent rise in species numbers is due to both improved genetic analysis and a push in conservation to encourage the protection of isolated and distinct lemur populations. Not everyone in the scientific community supports these taxonomic changes, with some preferring instead an estimate of 50 living species. ==Background== Since their arrival on Madagascar, a biogeographically isolated island with a unique mammalian fauna, lemurs have diversified both in behavior and morphology. Their diversity rivals that of the monkeys and apes found throughout the rest of the world, especially when the recently extinct subfossil lemurs are considered. Ranging in size from the Madame Berthe's mouse lemur, probably the world's smallest primate, to the extinct ''Archaeoindris fontoynonti'', the largest known prosimian, lemurs evolved diverse forms of locomotion, varying levels of social complexity, and unique adaptations to the local climate. They went on to fill many niches normally occupied by monkeys, squirrels, woodpeckers, and large grazing ungulates. In addition to the incredible diversity between lemur families, there has also been great diversification among closely related lemurs. The arrival of humans on the island 1,500 to 2,000 years ago has taken a significant toll, not only on the size of lemur populations, but also on their diversity. Due to habitat destruction and hunting, at least 17 species and 8 genera have gone extinct and many others have become threatened. Historically, lemurs ranged across the entire island inhabiting a wide variety of habitats, including dry deciduous forests, lowland forests, spiny thickets, subhumid forests, montane forest, and mangrove. Today, their collective range is restricted to 10% of the island, or approximately . Most of the remaining forests and lemurs are found along the periphery of the island. The center of the island, the Hauts-Plateaux, was converted by early settlers to rice paddies and grassland through slash-and-burn agriculture, known locally as ''tavy''. As erosion depleted the soil, the cyclical forest regrowth and burning ended as the forest gradually failed to return. In 2008, 41% of all lemur taxa were threatened with extinction while 42% were classified on the IUCN Red List as "Data Deficient". 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Taxonomy of lemurs」の詳細全文を読む スポンサード リンク
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