摘要：
Knowledge on ancient life and their interaction with the early planet relies largely on fossil records. Unlike animals and plants, heterotrophic bacteria were rarely preserved as fossils, and thus their evolutionary history remains poorly understood. Here, we developed a fossil-independent approach to understand the evolutionary timescale of marine Roseobacters, an alphaproteobacterial lineage dominantly associated with eukaryotic phytoplankton groups and playing a prominent role in global carbon and sulfur cycles. This approach is based on the spontaneous mutation rate (1.39×10-10 per nucleotide per cell division) determined for a model Roseobacter strain using a mutation accumulation experiment and growth rates typical for the taxon in the ocean. It first gives estimates of evolutionary time for closely related taxa, and subsequently extrapolates the timing estimates for more divergent lineages by leveraging the molecular clock approach. Working on ~200 gene families showing evidence of molecular clocks over the Roseobacter evolutionary history, this approach gives an estimated date of Roseobacter genome expansion in good agreement with an earlier fossil-based estimate of approximately 250 million years ago and is consistent with a hypothesis of a correlated evolutionary history between roseobacters and marine eukaryotic phytoplankton groups.
个人简历：
罗海伟博士2004年获4166金沙之选主页通道环境科学学士学位；2008年获美国南卡罗莱娜大学海洋微型生物学硕士学位；2010年获该校分子进化生物学和生物信息学博士学位，师从国际知名群体遗传学家Austin Hughes；2010-2014年在美国乔治亚大学海洋学系从事博士后研究，师从国际知名海洋微生物生态学家Mary Ann Moran；2015年起开始担任香港中文大学生命科学学院助理教授、博士生导师。近5年来，已发表了三十多篇SCI论文，均刊登在PNAS, ISME Journal等主流学术杂志上，其中影响因子超过9.0的以第一作者或者通讯作者发表的文章有10篇，他引800余次。曾多次被包括香港大学、韩国仁荷大学、沙特阿拉伯阿卜杜拉国王科技大学、台湾中央研究院生物多样性研究所、中科院土壤所和南海所、国家海洋局二所、同济大学等国内外知名高校和研究所邀请做学术访问。两次担任美国国家自然科学基金项目的特邀评审员和包括PNAS、ISME Journal在内的20多本国际主流杂志的特约审稿人。自2015年起，作为课题负责人获得了香港研资局（RGC）和香港环境与自然保育基金（ECF）等多项资助。目前罗海伟博士领导的香港中文大学海洋微生物学研究团队由6名博士生、4名博士后和多名客座研究人员组成。
