人們一直懷疑多倍性即基因組拷貝數(shù)的增加在新植物種起源中是否扮演著重要角色?，F(xiàn)存的被子植物有40%到80%被認為是多倍體。當前估計顯示僅有3%到4%的植物是由更晚的多倍體相關的物種分化而來的,。
最近,，德國明斯特大學、美國阿拉斯加大學和加拿大英屬哥倫比亞大學的研究人員提供證據(jù)證明多倍性是植物物種形成的主要原因,。研究人員證實15%的開花植物以及30%的蕨類植物均是由多倍性直接產(chǎn)生的,。這些研究人員由Troy Wood領導，他們采用細胞遺傳學方法及系統(tǒng)進化方法研究了一系列維管植物中出現(xiàn)多倍性的頻率,，對新物種的出現(xiàn)尤其關注,。
然而研究人員卻發(fā)現(xiàn)，以多倍體植物為祖先的植物類群并不比以二倍體植物為祖先的類群更容易產(chǎn)生物種,。文章作者之一Loren Rieseberg說：“多倍性似乎對多樣化速率沒有作用,，這一事實會減少人們有關“多倍性優(yōu)勢”的說法。”（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS August 18, 2009 vol. 106 no. 33 13875-13879
The frequency of polyploid speciation in vascular plants
Troy E. Wooda,b,1, Naoki Takebayashic, Michael S. Barkerb,d, Itay Mayrosee, Philip B. Greenspoond and Loren H. Riesebergb,d
aInstitute for Evolution and Biodiversity, University of Münster, 48149 Münster, Germany;
bDepartment of Biology, Indiana University, Bloomington, IN 47405;
cInstitute of Arctic Biology and Department of Biology and Wildlife, University of Alaska, Fairbanks, AK 99775; and
Departments of dBotany and
eZoology, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
Since its discovery in 1907, polyploidy has been recognized as an important phenomenon in vascular plants, and several lines of evidence indicate that most, if not all, plant species ultimately have a polyploid ancestry. However, previous estimates of the frequency of polyploid speciation suggest that the formation and establishment of neopolyploid species is rare. By combining information from the botanical community's vast cytogenetic and phylogenetic databases, we establish that 15% of angiosperm and 31% of fern speciation events are accompanied by ploidy increase. These frequency estimates are higher by a factor of four than earlier estimates and lead to a standing incidence of polyploid species within genera of 35% (n = 1,506). Despite this high incidence, we find no direct evidence that polyploid lines, once established, enjoy greater net species diversification. Thus, the widespread occurrence of polyploid taxa appears to result from the substantial contribution of polyploidy to cladogenesis, but not from subsequent increases in diversification rates of polyploid lines.
