A century of intermittent eco-evolutionary feedbacks resulted in novel trait combinations in invasive great lakes Alewives (Alosa pseudoharengus)

Species introductions provide opportunities to quantify rates and patterns of evolutionary change in response to novel environments. Alewives (Alosa pseudoharengus) are native to the East Coast of North America where they ascend coastal rivers to spawn in lakes, and then return to the ocean. Some populations have become landlocked within the last 350 years and diverged phenotypically from their ancestral marine population. More recently alewives were introduced to the Laurentian Great Lakes (~150 years ago), but these populations have not been compared to East Coast anadromous and landlocked populations. We quantified 95 years of evolution in foraging traits and overall body shape of Great Lakes alewives and compared patterns of phenotypic evolution of Great Lakes alewives to East Coast anadromous and landlocked populations. Our results suggest that gill raker spacing in Great Lakes alewives has evolved in a dynamic pattern that is consistent with responses to strong but intermittent ec...

物种引入为量化生物响应新环境的进化速率与模式提供了契机。西鲱（Alewives，学名Alosa pseudoharengus）原产于北美东海岸，它们会溯游沿海河流至湖泊产卵，随后返回海洋。部分种群在过去350年内演变为陆封型（landlocked），其表型与祖先海洋种群产生分化。更近时期（约150年前），西鲱被引入劳伦琴大湖（Laurentian Great Lakes），但这些种群尚未与东海岸的洄游型（anadromous）及陆封型种群进行比较。我们量化了大湖西鲱95年间觅食性状与整体体型的进化过程，并将其表型进化模式与东海岸洄游型及陆封型种群进行了比较。研究结果表明，大湖西鲱的鳃耙间距（gill raker spacing）呈现动态进化模式，这与生物对强烈但间歇性生态...