Understanding the role of Pleistocene climatic oscillations for evolution.A palaeogenomic case study of the European crow hybrid zone

了解更新世气候振荡对进化的作用。欧洲乌鸦杂交区的古基因组案例研究

• 批准号: 510399081
• 负责人: Professor Dr. Jochen B. W. Wolf
• 金额: --
• 依托单位: Lehrstuhl für Evolutionsbiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/510399081?language=en
• 关键词: Understanding; role; Pleistocene; climatic; oscillations

Speciation unfolds in space and time. Reproductive isolation between diverging populations most easily evolves during periods of geographic isolation and is put to the test upon secondary contact. Under the influence of ensuing gene exchange, the accumulated genome-wide divergence is expected to erode except around mutations experiencing divergent selection. Climatic oscillations during the Quaternary have presumably fueled such spatio-temporal population dynamics: during unfavorable environmental conditions populations contracted into disparate refugia, expanding their range as soon as conditions improved. This popular biogeographic model has gained support by population reconstruction based on genetic signatures of remnant population samples. It has rarely been tested using direct genetic evidence. Ancient genetic material can fill this gap as it allows observation of population dynamics through space and time. As a model, we here use the well-studied contact zone between grey-coated hooded and all-black carrion crows in Europe, hypothesized to be shaped by repeated events of isolation and recolonization during glacial-interglacial cycles. Combining genome-wide information from ~50 ancient samples (70,000 - 500 BP) with previously sequenced genomes from 118 extant individuals will allow (1) reconstructing the demographic history of European crows in space and time and (2) track the allelic dynamics of genes subject to sexual selection with known effects on prezygotic isolation. This research program allows direct scrutiny of the prevailing biogeographic model of biodiversity and provides fundamental insight to the dynamics of speciation.

物种形成在空间和时间中展开。不同种群之间的生殖隔离最容易在地理隔离期间演变，并在二次接触时受到考验。在随后的基因交换的影响下，积累的全基因组差异预计将被侵蚀，除了经历差异选择的突变周围。第四纪的气候振荡可能助长了这种时空种群动态：在不利的环境条件下，种群收缩成不同的避难所，一旦条件改善，它们的范围就会扩大。这种流行的地理模型已经得到了支持的人口重建的基础上遗传签名的残留人口样本。它很少使用直接的遗传证据进行测试。古老的遗传物质可以填补这一空白，因为它允许通过空间和时间观察种群动态。作为一个模型，我们在这里使用的灰色涂层头巾和全黑腐肉乌鸦在欧洲，假设是由重复的事件形成的隔离和隔离在冰川间冰期循环之间的接触区。将来自约50个古代样本（70，000 - 500 BP）的全基因组信息与来自118个现存个体的先前测序的基因组相结合，将允许（1）重建欧洲乌鸦在空间和时间上的人口统计学历史，以及（2）跟踪受性选择影响的基因的等位基因动态，已知对前合子隔离的影响。这项研究计划允许直接审查生物多样性的流行地理模型，并提供了基本的洞察力的物种形成的动态。