Drivers of evolutionary changes and community dynamics in ancient Lake Ohrid across taxa: A synthesis of molecular, fossil and sediment record data

巴尔干半岛的奥赫里德湖是欧洲最杰出的古湖泊，拥有非凡的物种丰富度和几个生物群体的高度特有性。人们对产生这种生物多样性的过程知之甚少。奥赫里德湖的底栖动物群体的初步遗传分析与分子钟估计表明，大多数的地方性类群intralacutine随着时间的推移，没有重大变化的多样化率，指出没有灾难性事件的地质历史lake.This假设，除其他外，启发了在奥赫里德湖的ICDP运动（SCOPSCO）。从2013年4月初开始，SCOPSCO钻井作业成为有史以来最成功的ICDP湖泊钻井活动之一。约2013年5月下旬，从奥赫里德湖采集了2100米的沉积物样本。从四个不同地点回收沉积物，总回收率> 95%。初步分析表明，岩心提供了高质量的古湖沼学数据的连续记录，并载有丰富的微化石和宏化石组合。此外，对岩心采集器样本中硅藻组合的初步分析显示，硅藻群落随时间发生了显著变化，因此，目前建议的主要目标是一方面利用来自现存物种的分子钟信息以及微观和宏观化石数据，另一方面利用来自沉积物岩心的古环境数据（沉积学，火山灰地层学和古生境信息），另一方面，推断在古代奥赫里德湖的几个类群的进化变化和社区周转的驱动程序。总体工作的假设是，在奥赫里德湖的灾难性事件和高生态恢复力的情况下，可能减轻了不利的进化影响的环境干扰湖泊类群。相反，这些变化可能主要引发了群落的更替。这一提议为古湖泊研究提供了一种新的方法。在SCOPSCO钻探活动提供的协同作用的基础上，它结合了来自不同动物和原生生物群体的暂时明确的分子，古环境，古生物学和进化信息。此外，这些信息主要是从年龄控制的沉积物记录数据中获得的，这些数据涵盖了古湖泊的整个历史。

The Balkan Lake Ohrid is the most outstanding European ancient lake with an extraordinary species richness and a high degree of endemism in several groups of organisms. The processes generating this biodiversity are poorly understood. Preliminary genetic analyses of selected benthic animal groups in Lake Ohrid together with molecular clock estimations indicated that most of the endemic taxa evolved intralacustrine without major changes in diversification rates over time, pointing to an absence of catastrophic events during the geological history of the lake.This hypothesis has, among others, inspired the ICDP campaign (SCOPSCO) in Lake Ohrid. Starting in early April 2013, the SCOPSCO drilling operation became one of the most successful ICDP lake drilling campaigns ever conducted. Ca. 2100 m of sediment were sampled from Lake Ohrid until late May 2013. The sediments were recovered from four different sites with a total recovery of > 95%. First analyses indicated that the cores provide a continuous record of high-quality paleolimnological data and bear rich micro- and macrofossil assemblages. Moreover, preliminary analyses of diatom assemblages from core catcher samples showed significant shifts in diatom communities over time.Therefore, the main goal of the current proposal is to use a combination of molecular clock information derived from extant species as well as micro- and macrofossil data, on the one hand, and paleoenvironmental data from sediment cores (sedimentological, tephrostratigraphic, and paleo-habitat information), on the other, to infer the drivers of evolutionary changes and community turnovers in ancient Lake Ohrid across several taxa. The overall working hypothesis is that the absence of catastrophic events in Lake Ohrid and its high ecological resilience may have mitigated adverse evolutionary effects of environmental disturbances on lake taxa. Instead, these changes may have mainly triggered community turnovers.This proposal provides a novel approach in ancient lake studies. Building upon the synergies offered by the SCOPSCO drilling campaign, it combines temporarily explicit molecular, paleoenvironmental, paleontological, and evolutionary information from different animal and protist groups. Moreover, this information is primarily obtained from age-controlled sediment record data, which span the entire history of an ancient lake.