The origin of snakes: revealing the ecology, behavior, and evolutionary history of early snakes using genomics, phenomics, and the fossil record.
The origin of snakes: revealing the ecology, behavior, and evolutionary history of early snakes using genomics, phenomics, and the fossil record.
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DOI：
10.1186/s12862-015-0358-5
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发表时间：
2015-05-20
影响因子：
3.4
通讯作者：
Gauthier JA
中科院分区：
文献类型：
--
作者：
Hsiang AY;Field DJ;Webster TH;Behlke AD;Davis MB;Racicot RA;Gauthier JA
蛇的高度衍生的形态和惊人的多样性长期以来引发了关于蛇的总类群(泛蛇类)和冠蛇(蛇类)的生态和进化起源的争论。尽管关于最早的蛇的生态、行为和起源的猜测很多，但对蛇的起源进行严格的、广泛的分析还没有尝试，部分原因是缺乏关于早期茎蛇的足够的古生物学数据。在这里，我们提出了第一个全面的解析重建冠蛇的祖先和蛇的总群体的祖先，通过多种祖先状态重建的方法推断出来的。我们使用综合数据的方法，其中包括来自灭绝的冠蛇化石记录的新信息，关于茎蛇Najash rionegrina，Dinilysia pathonica和Coniopits preens的新数据，以及对表型同型在化石和现代蛇的主要分支中的分布的更深层次的理解。此外，我们使用新的‘尖端测年’和传统的基于节点的方法来推断时间校准的系统发育，为蛇的早期进化史中的时间模式提供了新的见解。综合的祖先状态重建表明，冠蛇的祖先和全群蛇的祖先都是夜间活动的、广泛觅食的、非约束性的隐形猎人。它们可能捕食软体脊椎动物和无脊椎动物猎物，这些猎物与头部大小相当，并在温暖、灌溉良好和植被良好的环境中占据陆地环境。据推测，蛇群起源于早白垩世中期(约128.5 Ma)，冠群起源于约2,000万年后的阿尔比亚期。我们推断的发散年龄为白垩纪-古近纪(K-PG)大灭绝后蛇类多样性的主要辐射提供了强有力的证据，澄清了现存蛇辐射的模式和时间。虽然蛇冠群很可能出现在冈瓦那超大陆，但我们的结果表明，蛇冠群可能起源于劳亚大陆。我们的研究为蛇起源的时间、地点和方式提供了新的见解，并呈现了迄今为止蛇早期进化的最完整图景。更广泛地说，我们展示了将化石和表型数据包括在旨在进行系统发育拓扑推断和祖先状态重建的联合分析中的显著影响。本文的在线版本(doi：10.1186/s12862-0150358-5)包含补充材料，授权用户可以使用。
The highly derived morphology and astounding diversity of snakes has long inspired debate regarding the ecological and evolutionary origin of both the snake total-group (Pan-Serpentes) and crown snakes (Serpentes). Although speculation abounds on the ecology, behavior, and provenance of the earliest snakes, a rigorous, clade-wide analysis of snake origins has yet to be attempted, in part due to a dearth of adequate paleontological data on early stem snakes. Here, we present the first comprehensive analytical reconstruction of the ancestor of crown snakes and the ancestor of the snake total-group, as inferred using multiple methods of ancestral state reconstruction. We use a combined-data approach that includes new information from the fossil record on extinct crown snakes, new data on the anatomy of the stem snakes Najash rionegrina, Dinilysia patagonica, and Coniophis precedens, and a deeper understanding of the distribution of phenotypic apomorphies among the major clades of fossil and Recent snakes. Additionally, we infer time-calibrated phylogenies using both new ‘tip-dating’ and traditional node-based approaches, providing new insights on temporal patterns in the early evolutionary history of snakes. Comprehensive ancestral state reconstructions reveal that both the ancestor of crown snakes and the ancestor of total-group snakes were nocturnal, widely foraging, non-constricting stealth hunters. They likely consumed soft-bodied vertebrate and invertebrate prey that was subequal to head size, and occupied terrestrial settings in warm, well-watered, and well-vegetated environments. The snake total-group – approximated by the Coniophis node – is inferred to have originated on land during the middle Early Cretaceous (~128.5 Ma), with the crown-group following about 20 million years later, during the Albian stage. Our inferred divergence dates provide strong evidence for a major radiation of henophidian snake diversity in the wake of the Cretaceous-Paleogene (K-Pg) mass extinction, clarifying the pattern and timing of the extant snake radiation. Although the snake crown-group most likely arose on the supercontinent of Gondwana, our results suggest the possibility that the snake total-group originated on Laurasia. Our study provides new insights into when, where, and how snakes originated, and presents the most complete picture of the early evolution of snakes to date. More broadly, we demonstrate the striking influence of including fossils and phenotypic data in combined analyses aimed at both phylogenetic topology inference and ancestral state reconstruction. The online version of this article (doi:10.1186/s12862-015-0358-5) contains supplementary material, which is available to authorized users.
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影响因子：
3
作者：
Bollback JP
通讯作者：
Bollback JP
影响因子：
6.5
作者：
Finarelli, JA;Flynn, JJ
通讯作者：
Flynn, JJ
影响因子：
64.8
作者：
Caldwell, MW;Lee, MSY
通讯作者：
Lee, MSY
影响因子：
0.8
作者：
ANDERSON, S;MARCUS, LF
通讯作者：
MARCUS, LF
影响因子：
2
作者：
Eskew, E. A.;Willson, J. D.;Winne, C. T.
通讯作者：
Winne, C. T.