Cerca José, Cotoras Darko D, Santander Cindy G, Bieker Vanessa C, Hutchins Leke, Morin-Lagos Jaime, Prada Carlos F, Kennedy Susan, Krehenwinkel Henrik, Rominger Andrew J, Meier Joana, Dimitrov Dimitar, Struck Torsten H, Gillespie Rosemary G
Berkeley Evolab, Department of Environmental Science, Policy, and Management, UC Berkeley, Berkeley, California, USA.
Frontiers in Evolutionary Zoology, Natural History Museum, University of Oslo, Oslo, Norway.
Mol Ecol. 2023 Sep;32(18):4971-4985. doi: 10.1111/mec.17082. Epub 2023 Jul 29.
The repeated evolution of phenotypes provides clear evidence for the role of natural selection in driving evolutionary change. However, the evolutionary origin of repeated phenotypes can be difficult to disentangle as it can arise from a combination of factors such as gene flow, shared ancestral polymorphisms or mutation. Here, we investigate the presence of these evolutionary processes in the Hawaiian spiny-leg Tetragnatha adaptive radiation, which includes four microhabitat-specialists or ecomorphs, with different body pigmentation and size (Green, Large Brown, Maroon, and Small Brown). We investigated the evolutionary history of this radiation using 76 newly generated low-coverage, whole-genome resequenced samples, along with phylogenetic and population genomic tools. Considering the Green ecomorph as the ancestral state, our results suggest that the Green ecomorph likely re-evolved once, the Large Brown and Maroon ecomorphs evolved twice and the Small Brown evolved three times. We found that the evolution of the Maroon and Small Brown ecomorphs likely involved ancestral hybridization events, while the Green and Large Brown ecomorphs likely evolved through novel mutations, despite a high rate of incomplete lineage sorting in the dataset. Our findings demonstrate that the repeated evolution of ecomorphs in the Hawaiian spiny-leg Tetragnatha is influenced by multiple evolutionary processes.
表型的反复进化为自然选择在推动进化变化中的作用提供了明确证据。然而，反复出现的表型的进化起源可能难以厘清，因为它可能源于基因流动、共享祖先多态性或突变等多种因素的组合。在这里，我们研究了夏威夷刺腿肖蛸适应性辐射中这些进化过程的存在情况，该辐射包括四种微生境特化类型或生态形态，具有不同的体色和体型（绿色、大型棕色、栗色和小型棕色）。我们使用76个新生成的低覆盖度全基因组重测序样本以及系统发育和群体基因组工具，研究了这种辐射的进化历史。以绿色生态形态作为祖先状态，我们的结果表明，绿色生态形态可能只重新进化了一次，大型棕色和栗色生态形态进化了两次，小型棕色生态形态进化了三次。我们发现，栗色和小型棕色生态形态的进化可能涉及祖先杂交事件，而绿色和大型棕色生态形态可能是通过新的突变进化而来，尽管数据集中存在较高的不完全谱系分选率。我们的研究结果表明，夏威夷刺腿肖蛸生态形态的反复进化受到多种进化过程的影响。
