Convergent Adaptation of True Crabs (Decapoda: Brachyura) to a Gradient of Terrestrial Environments
Convergent Adaptation of True Crabs (Decapoda: Brachyura) to a Gradient of Terrestrial Environments
复制标题
真正的螃蟹（十足目：Brachyura）对陆地环境梯度的趋同适应
DOI：
10.1093/sysbio/syad066
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发表时间：
2023
影响因子：
6.5
通讯作者：
Daniels, Savel R.
中科院分区：
文献类型：
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作者：
Wolfe, Joanna M.;Ballou, Lauren;Luque, Javier;Watson-Zink, Victoria M.;Ahyong, Shane T.;Barido-Sottani, Joëlle;Chan, Tin-Yam;Chu, Ka Hou;Crandall, Keith A.;Daniels, Savel R.
对于大多数陆地生物多样性而言，人们对海洋祖先的进化适应途径知之甚少，通常将其视为二元特征。真正的螃蟹，十足类甲壳纲下目Brachyura，包括超过7600种，代表了惊人的形态和生态多样性，包括反复适应非海洋栖息地。在这里，我们重建Brachyura的进化历史，使用新的和已发表的10个基因序列的344提示跨越88的109个Brachyuran家庭。使用36个新审查的化石校准，我们推断，brachyurans最有可能在三叠纪分歧，在白垩纪晚期和古近纪早期的家庭水平分裂。相比之下，根的年龄被低估了328个化石出现的自动采样明确纳入树之前，这表明这样的模型是一个不适合下异质化石保存。我们最近定义的环境协会的特点进行分类的梯度从海洋到陆地的生活方式的过渡。我们估计，螃蟹离开海洋环境至少7和多达17次收敛，并返回到海洋从非海洋环境中至少两次。虽然最高度陆生和许多淡水适应蟹集中在Thoracotremata，贝叶斯阈值模型的祖先状态重建未能识别转移到更高的陆地等级由于所需的基本变化的程度。整个谱系都栖息在潮间带和边缘海洋环境中，证实了陆地适应的早期阶段具有较低的进化门槛的推论。我们的框架和广泛的新化石和自然历史数据集将使未来的非海洋适应在形态和分子水平上的比较。螃蟹提供了一个重要的窗口，了解适应新环境的早期过程，以及可能有助于预测这些途径的不同程度的进化限制。[Brachyura;收敛进化;甲壳类;发散时间;化石校准;分子生物学;陆地化;阈值模型。]
For much of terrestrial biodiversity, the evolutionary pathways of adaptation from marine ancestors are poorly understood and have usually been viewed as a binary trait. True crabs, the decapod crustacean infraorder Brachyura, comprise over 7600 species representing a striking diversity of morphology and ecology, including repeated adaptation to non-marine habitats. Here, we reconstruct the evolutionary history of Brachyura using new and published sequences of 10 genes for 344 tips spanning 88 of 109 brachyuran families. Using 36 newly vetted fossil calibrations, we infer that brachyurans most likely diverged in the Triassic, with family-level splits in the late Cretaceous and early Paleogene. By contrast, the root age is underestimated with automated sampling of 328 fossil occurrences explicitly incorporated into the tree prior, suggesting such models are a poor fit under heterogeneous fossil preservation. We apply recently defined trait-by-environment associations to classify a gradient of transitions from marine to terrestrial lifestyles. We estimate that crabs left the marine environment at least 7 and up to 17 times convergently, and returned to the sea from non-marine environments at least twice. Although the most highly terrestrial- and many freshwater-adapted crabs are concentrated in Thoracotremata, Bayesian threshold models of ancestral state reconstruction fail to identify shifts to higher terrestrial grades due to the degree of underlying change required. Lineages throughout our tree inhabit intertidal and marginal marine environments, corroborating the inference that the early stages of terrestrial adaptation have a lower threshold to evolve. Our framework and extensive new fossil and natural history datasets will enable future comparisons of non-marine adaptation at the morphological and molecular level. Crabs provide an important window into the early processes of adaptation to novel environments, and different degrees of evolutionary constraint that might help predict these pathways. [Brachyura; convergent evolution; crustaceans; divergence times; fossil calibration; molecular phylogeny; terrestrialization; threshold model.]