Biogeographical dynamics of plant taxa and climate-landscape history of the Eurasian steppe belt: Genes documenting history.

欧亚草原是北半球最大的草原地区，西接欧西伯利亚部分，东接蒙汉部分。它在匈牙利盆地和阿穆尔河之间绵延8000公里，在中欧和东北亚有一些较小的飞地。以大型脊椎动物化石为主要依据，认为该草原的形成始于亚洲下中新世，并在中上中新世向西延伸，因此在中新世/上新世界线上可能存在一条连续的草原带，最迟在上新世末期。原始的草原生境被广泛地转变为农业景观，而次生草原由于人类的影响而在主要森林开放后起源于欧洲。我们建议将系统地理学和生物地理学方法应用于典型的和广泛分布的草原指示种，以了解欧亚草原带的地理起源和气候-景观历史。我们的关注点是欧亚西部草原带，这是欧洲-西伯利亚草原。特别是在第四纪气候宏观旋回期间，草原面临着大范围的范围转移、范围收缩和扩张。我们打算用分子系统学方法(核基因测序和通过GBS进行全基因组SNP分析)对15个不同的植物物种/物种组进行比较分析，并用系统发育和系统地理学方法(过时的系统发育、生物地理重建的贝叶斯方法和最大似然方法)分析数据。因此，我们希望在扩大和/或细分草原生境的过程中追踪过去和正在进行的原位演化，并确定由于气候或地理变化或停滞而导致的强烈物种形成(或缺乏物种形成)的时间，从中新世到现在影响欧亚大陆西部。

The Eurasian steppe, consisting of the Euro-Siberian part in the west and the Mongol-Chinese part in the east, is the largest steppe region in the Northern Hemisphere. It stretches across 8000 km between the Hungarian basin and the Amur and has some smaller exclaves in Middle Europe and northeastern Asia. Based mainly on macrofossils of vertebrates it is assumed that the formation of the steppe started in the Lower Miocene in Asia and extended westwards in the Middle to Upper Mio¬cene, so that a continuous steppe belt was probably present at the Miocene/Pliocene boundary, latest at the end of the Pliocene. Pristine steppe habitats were widely transformed into agricultural landscapes, while secondary steppe originated in Europe after opening of the dominating forests due to human influence. We propose to apply phylogeographic and biogeographic methods on typical and widespread steppe in-dicator species to understand the geographic origin and the climate-landscape history of the Eurasian steppe belt. Our focal point is the western Eurasian steppe belt, which is the Euro-Siberian steppe. Especially during the Quaternary climate macro-cycles, the steppe faced extensive range shift, range contractions and expansions. We intend to comparatively analyze 15 diverse plant species/species groups with molecular-systematics methods (sequencing of nuclear genes, and genome-wide SNP analysis through GBS) and analyze the data with phylogenetic and phylogeographic methods (dated phylogenies, Bayesian and maximum-likelihood methods on biogeography reconstruction). Thus we want to trace past and ongoing in-situ evolution in expanding and/or subdividing steppe habitats, as well as identify times of intense speciation (or lack thereof) due to climate or geographical changes or stasis, influencing western Eurasia from Miocene till present.