Introgression and niche dynamics in two ecologically divergent species

两个生态分歧物种的基因渗入和生态位动态

基本信息

批准号：
22770021
负责人：
MIMURA Makiko
金额：
$ 2.41万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Young Scientists (B)
财政年份：
2010
资助国家：
日本
起止时间：
2010 至 2012
项目状态：
已结题

项目摘要

The margins of a species’ range might be most vulnerable under climate changes, but it may also undergo significant evolutionary change due to drastic population dynamics, e.g. contacts with new species. We tested(1) differences in range shift and its consequences, along with past climate change, in two closely related but ecologically distinct Rubus species (R. palmatus and R. grayanus) and(2) asymmetric introgression between these two species at the contact zone. We studied nine populations in total from southern and northern margins of two species. Coalescent analysis based on 12 putatively functional gene sequences together with niche modeling during GLM, suggested that the southernmost populations of R. palmatus perhaps persisted since before the Last Glacial Maximum (LGM). Conversely, the R. grayanuspopulations diverged relatively recently and likely represent young outposts of a northbound range shift. Significant introgression was only detected between R. palmatus and R. grayanus on Yakushima Island, where the margins of the species’ ranges overlapped parapatrically. Structure analysis in ten populations on the contact zone on the island suggests gradual introgression along the altitudes. Further investigation is in progress to test whether any gene under selection is moving from one to another species faster than neutral expectation. We conclude that introgression between these relatives has recently taken place at these marginal populations induced by climate changes. Introgression could increase the evolutionary potential at the margins of the species’ range under extreme environments in the species’ niches.

在气候变化下，物种范围的边缘可能最脆弱，但由于人口动态的急剧，它也可能会发生重大的进化变化，例如与新物种的接触。我们在两种密切相关但生态上不同的鲁布斯物种（R. palmatus和R. grayanus）和（2）在接触区的这两个物种之间进行了两种密切相关但生态上不同的rubus物种（R. palmatus和R. grayanus）和（2）接触区之间的不对称渗入。我们从两个物种的南部和北部边缘研究了9个人群。基于12个推定功能基因序列以及GLM期间的小众建模的合并分析表明，自上次冰川最大值（LGM）以来，最南的帕尔马图斯河河河种群可能持续存在。相反，Grayanuspopulation最近相对较远，可能代表了北向范围转移的年轻哨所。只有在Yakushima岛上的帕尔马图斯和R. grayanus之间检测到显着的渗入，该物种的边缘范围占据了副群的范围。该岛接触区的十个人群中的结构分析表明沿高度的等级渗入。进一步研究正在进行进一步的研究，以测试任何被选择的基因是否比中性期望更快地从一个物种转移到另一个物种。我们包括这些亲戚之间的侵入最近发生在气候变化引起的这些边际种群中。渗入可能会在物种壁ni的极端环境下增加该物种范围内的进化潜力。