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研究揭示爆炸型适应性辐射的生态学和基因组学基础
2020-08-28 15:46

瑞士伯尔尼大学Ole Seehausen、Matthew D. McGee等研究人员合作揭示爆炸型适应性辐射的生态学和基因组学基础。相关论文于2020年8月26日在线发表于国际学术期刊《自然》。

通过重建所有目前报道的丽鱼科鱼物种的大型系统发育史,研究人员发现爆炸性物种仅集中在几个大型年轻湖泊的物种群中。物种形成率的增加与缺乏顶级捕食者有关;但是,这不足以解释爆炸性物种。在整个湖辐射中,研究人员观察到物种形成率与大插入或缺失多态性的富集之间存在正相关关系。
 
在维多利亚湖中发现的最快速的丽鱼科动物辐射中,100个丽鱼科动物基因组的组装揭示了异常的“基因组潜力”,即数百种古老的单倍型具有插入或缺失多态性,其中许多与特定的生态学相关,并且在生态学上相似于非洲其他地方的其他较旧辐射产生的物种。网络分析揭示出通过重组旧单倍型产生的非树状进化,而生态类群的起源则集中在辐射的早期。
 
这些结果表明,生态机遇、性选择和出色基因组潜力的结合是理解爆炸型适应性辐射的关键。
 
据介绍,世系间的物种形成率差异很大,人们对驱动年轻适应性辐射进化中物种形成事件的快速连续性仍然未完全了解。丽鱼科鱼类提供了这种变异的一个典型例子,其中包括许多缓慢形成的谱系以及一些异常大而快速的辐射进化。
 
附:英文原文

Title: The ecological and genomic basis of explosive adaptive radiation

Author: Matthew D. McGee, Samuel R. Borstein, Joana I. Meier, David A. Marques, Salome Mwaiko, Anthony Taabu, Mary A. Kishe, Brian OMeara, Rmy Bruggmann, Laurent Excoffier, Ole Seehausen

Issue&Volume: 2020-08-26

Abstract: Speciation rates vary considerably among lineages, and our understanding of what drives the rapid succession of speciation events within young adaptive radiations remains incomplete1,2,3,4,5,6,7,8,9,10,11. The cichlid fish family provides a notable example of such variation, with many slowly speciating lineages as well as several exceptionally large and rapid radiations12. Here, by reconstructing a large phylogeny of all currently described cichlid species, we show that explosive speciation is solely concentrated in species flocks of several large young lakes. Increases in the speciation rate are associated with the absence of top predators; however, this does not sufficiently explain explosive speciation. Across lake radiations, we observe a positive relationship between the speciation rate and enrichment of large insertion or deletion polymorphisms. Assembly of 100 cichlid genomes within the most rapidly speciating cichlid radiation, which is found in Lake Victoria, reveals exceptional ‘genomic potential’—hundreds of ancient haplotypes bear insertion or deletion polymorphisms, many of which are associated with specific ecologies and shared with ecologically similar species from other older radiations elsewhere in Africa. Network analysis reveals fundamentally non-treelike evolution through recombining old haplotypes, and the origins of ecological guilds are concentrated early in the radiation. Our results suggest that the combination of ecological opportunity, sexual selection and exceptional genomic potential is the key to understanding explosive adaptive radiation.

DOI: 10.1038/s41586-020-2652-7

Source: https://www.nature.com/articles/s41586-020-2652-7

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:43.07
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

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