Leitwein Maeva, Garza John Carlos, Pearse Devon E
Technopôle Brest-Iroiserue Dumont d'Urville Institut Universitaire Européen de la Mer (IUEM) University of Brest Plouzané France; Institute of Marine Sciences University of California Santa Cruz CA USA; Present address: Institut des Sciences de l'Evolution de Montpellier (ISEM) UMR 5554 Université de ´Montpellier Montpellier Cedex 5 France.
Institute of Marine Sciences University of California Santa Cruz CA USA; Fisheries Ecology Division Southwest Fisheries Science Center National Marine Fisheries Service Santa Cruz CA USA.
Evol Appl. 2016 Oct 27;10(1):56-67. doi: 10.1111/eva.12416. eCollection 2017 Jan.
The streams draining of into San Francisco Bay, California, have been impacted by habitat alteration for over 150 years, and roads, dams, water diversions, and other impediments now block the paths of many aquatic migratory species. These changes can affect the genetic structure of fish populations, as well as driving adaptive evolution to novel environmental conditions. Here, we determine the evolutionary relationships of San Francisco Bay Area steelhead/rainbow trout () populations and show that (i) they are more closely related to native coastal steelhead than to the California Central Valley lineage, with no evidence of introgression by domesticated hatchery rainbow trout, (ii) populations above and below barriers within watersheds are each other's closest relatives, and (iii) adaptive genomic variation associated with migratory life-history traits in shows substantial evolutionary differences between fish above and below dams. These findings support continued habitat restoration and protection of San Francisco Bay Area populations and demonstrate that ecological conditions in novel habitats above barriers to anadromy influence life-history evolution. We highlight the importance of considering the adaptive landscape in conservation and restoration programs for species living in highly modified habitats, particularly with respect to key life-history traits.
流入加利福尼亚州旧金山湾的溪流在过去150多年里一直受到栖息地改变的影响，道路、水坝、引水工程及其他障碍如今阻断了许多水生洄游物种的路径。这些变化会影响鱼类种群的遗传结构，还会推动其对新环境条件的适应性进化。在此，我们确定了旧金山湾区虹鳟种群的进化关系，并表明：（i）它们与本地沿海虹鳟的亲缘关系比与加利福尼亚中央谷地谱系的更近，且没有驯化的孵化场虹鳟基因渗入的证据；（ii）流域内障碍上下游的种群互为亲缘关系最近的种群；（iii）与洄游生活史特征相关的适应性基因组变异在水坝上下游的鱼类之间表现出显著的进化差异。这些发现支持持续开展旧金山湾区虹鳟种群的栖息地恢复和保护工作，并表明溯河洄游障碍上方新栖息地的生态条件会影响生活史进化。我们强调了在针对生活在高度改变栖息地中的物种的保护和恢复计划中考虑适应性景观的重要性，尤其是对于关键生活史特征而言。
