現生鼩鼴（shrew-like moles）棲息在中國西南的橫斷山系及周邊地區，是鼴科中最原始的一支。由於形態上的保守性和野外採樣的難度，有關該類群生物系統學的研究仍十分有限。另外，現生鼩鼴的分布區是全球最重要的生物多樣性熱點地區之一。中新世以來的全球氣候變化和頻繁的地質運動造就了這一區域複雜的地理景觀，極大塑造了特有類群的遺傳格局。然而，該地區生物多樣性的發生機制仍存在一定爭議。因此，通過分子系統發育手段研究現生鼩鼴可以有效地聯繫起生物和地區兩大模式系統，意義重大。
最新一期的BMC Evolutionary Biology雜誌刊登了中科院昆明動物研究所蔣學龍研究組的近期成果Multilocus phylogeny and cryptic diversity in Asian shrew-like moles (Uropsilus， Talpidae)： implications for taxonomy and conservation。該研究第一次通過分子系統發育方法解決了鼩鼴亞科現生類群長期遺留的問題。通過對2個線粒體基因和8個核基因序列進行分析，構建了採自不同地區的鼩鼴樣品的系統發育關係，並基於化石和分子校正點估算了物種分歧時間。
研究結果顯示，現生鼩鼴的物種分化時間（6.32-0.82Ma）與中新世以來的氣候變化和造山運動有強烈的對應關係，而目前主要的pre-Pleistocene speciation假說和Pleistocene speciation pump假說都不能較好地解釋這一物種分化模式。與基因樹的結果基本一致，基於溯祖理論模型（Coalescent model）構建的物種樹認為目前認可的5個物種代表了10個進化上獨立的支系，提示該類群的生物多樣性被嚴重地低估。因為這些獨立進化的支系（有效種）大都分布狹域，文章還從保護遺傳學的角度建議它們的保護等級亟待提高。
該研究得到了國家自然基金（31301869，31272276）、中科院知識創新計劃（KSZD-EW-2-011）和遺傳資源與進化國家重點實驗室（GREKF11-03）的資助。博士研究生萬韜和助理研究員何鍇為本文的共同第一作者。（生物谷Bioon.com）
生物谷推薦的英文摘要
BMC Evolutionary Biology doi:10.1186/1471-2148-13-232
Multilocus phylogeny and cryptic diversity in Asian shrew-like moles (Uropsilus， Talpidae)： implications for taxonomy and conservation
Tao Wan12， Kai He13 and Xue-Long Jiang1*
Background
The genus Uropsilus comprises a group of terrestrial， montane mammals endemic to the Hengduan and adjacent mountains. These animals are the most primitive living talpids. The taxonomy has been primarily based on cursory morphological comparisons and the evolutionary affinities are little known. To provide insight into the systematics of this group， we estimated the first multi-locus phylogeny and conducted species delimitation， including taxon sampling throughout their distribution range.
Results
We obtained two mitochondrial genes (~1， 985 bp) and eight nuclear genes (~4， 345 bp) from 56 specimens. Ten distinct evolutionary lineages were recovered from the three recognized species， eight of which were recognized as species/putative species. Five of these putative species were found to be masquerading as the gracile shrew mole. The divergence time estimation results indicated that climate change since the last Miocene and the uplift of the Himalayas may have resulted in the diversification and speciation of Uropsilus.
Conclusions
The cryptic diversity found in this study indicated that the number of species is strongly underestimated under the current taxonomy. Two synonyms of gracilis (atronates and nivatus) should be given full species status， and the taxonomic status of another three potential species should be evaluated using extensive taxon sampling， comprehensive morphological， and morphometric approaches. Consequently， the conservation status of Uropsilus spp. should also be re-evaluated， as most of the species/potential species have very limited distribution.