Phylogeography of the harvestman genus Metasiro (Arthropoda, Arachnida, Opiliones) reveals a potential solution to the Pangean paradox

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• 作者：Ronald M. Clouse ; Prashant P. Sharma ; Jessie C. Stuart…
• 关键词：Apalachicola River ; Appalachia ; Cyphophthalmi ; Hydrochory ; Pangea ; Vicariance
• 刊名：Organisms Diversity & Evolution
• 出版年：2016
• 出版时间：March 2016
• 年：2016
• 卷：16
• 期：1
• 页码：167-184
• 全文大小：2,269 KB
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• 作者单位：Ronald M. Clouse (1) (2)
  Prashant P. Sharma (1) (3)
  Jessie C. Stuart (4)
  Lloyd R. Davis (5)
  Gonzalo Giribet (6)
  Sarah L. Boyer (7)
  Ward C. Wheeler (1)
  
  1. Division of Invertebrate Zoology, American Museum of Natural History, 200 Central Park West, New York, NY, 10024, USA
  2. Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, 9201 University City Blvd., Bioinformatics, Room 224, Charlotte, NC, 28223, USA
  3. Department of Zoology, University of Wisconsin–Madison, 351 Birge Hall, Madison, WI, 53706, USA
  4. Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA
  5. 3920 NW 36th Place, Gainesville, FL, 32606, USA
  6. Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA
  7. Biology Department, Macalester College, 1600 Grand Avenue, Saint Paul, MN, 55105, USA
  
• 刊物主题：Biodiversity; Evolutionary Biology; Developmental Biology; Animal Systematics/Taxonomy/Biogeography; Plant Systematics/Taxonomy/Biogeography;
• 出版者：Springer Berlin Heidelberg
• ISSN：1618-1077

文摘

At both global and local scales, mite harvestmen (Opiliones, Cyphophthalmi) have been shown to have achieved their current global distribution strictly through vicariance. However, the implicit low dispersal capability of this group does not explain how they expand their ranges and come to occupy enormous landmasses prior to rifting. To investigate at the population level the limited vagility that characterizes the suborder generally, and how its dispersal capacity determines diversification dynamics, range expansion, and historical biogeography, we examined as a test case the phylogeography of the genus Metasiro. This genus consists of three widely separated, morphologically cryptic species that inhabit the Southeastern United States. Distances between sampling sites spanned a range of geographic scales, from 4 m to over 500 km. Population structure was inferred from fragments of six loci (three mitochondrial, three nuclear) amplified from 221 specimens. We tested for population structure and gene flow, constructed a dated phylogeny of the genus, and developed a program for estimating the effective population size with confidence intervals. Individuals of Metasiro americanus demonstrate remarkable population structure at scales of less than 25 m, but populations vary in their haplotypic diversity, and some exhibit evidence of historical gene flow. The estimated timing of cladogenesis within the genus accords closely with the geological history of the North American coastline, and the three species are at the endpoints of large watersheds. This suggests that mite harvestman lineages expand their ranges by hydrochory, providing for the first time a plausible mechanism whereby these animals dispersed across Pangea despite their low vagility in stable environments.