Asymmetric dispersal allows an upstream region to control population structure throughout a species’ range

James M. Pringle1, April M. H. Blakeslee2, James E. Byers3, Joe Roman4
1Ocean Process Analysis Laboratory, University of New Hampshire, Durham, NH 03824, USA,
2bMarine Invasions Laboratory, Smithsonian Environmental Research Center, Edgewater, MD 21037;
3cOdum School of Ecology, University of Georgia, Athens, GA 30602; and
4dGund Institute for Ecological Economics, University of Vermont, Burlington, VT 05405

Tóm tắt

In a single well-mixed population, equally abundant neutral alleles are equally likely to persist. However, in spatially complex populations structured by an asymmetric dispersal mechanism, such as a coastal population where larvae are predominantly moved downstream by currents, the eventual frequency of neutral haplotypes will depend on their initial spatial location. In our study of the progression of two spatially separate, genetically distinct introductions of the European green crab ( Carcinus maenas ) along the coast of eastern North America, we captured this process in action. We documented the shift of the genetic cline in this species over 8 y, and here we detail how the upstream haplotypes are beginning to dominate the system. This quantification of an evolving genetic boundary in a coastal system demonstrates that novel genetic alleles or haplotypes that arise or are introduced into upstream retention zones (regions whose export of larvae is not balanced by import from elsewhere) will increase in frequency in the entire system. This phenomenon should be widespread when there is asymmetrical dispersal, in the oceans or on land, suggesting that the upstream edge of a species’ range can influence genetic diversity throughout its distribution. Efforts to protect the upstream edge of an asymmetrically dispersing species’ range are vital to conserving genetic diversity in the species.

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Tài liệu tham khảo

DL Hartl A Primer of Population Genetics (Sinauer, Sunderland, MA, 1981).

10.1086/341519

10.1098/rspb.2006.3469

10.1017/S0016672398003139

10.1890/0012-9615(2003)073[0173:MLDOPD]2.0.CO;2

10.1126/science.1095210

10.1146/annurev.py.28.090190.001035

10.1126/science.1072678

10.3354/meps260083

10.3354/meps335069

10.1186/1471-2148-8-235

10.1093/genetics/88.4.813

10.1086/648311

10.3354/meps313027

J Largier, The importance of retention zones in the dispersal of larvae. Proc American Fish Society Symp 42, 105–122 (2004).

T Say, An account of the Crustacea of the United States. J Acad Nat Sci Phila 1, 56–57 (1817).

D Audet, et al., Geographical expansion of a nonindigenous crab, Carcinus maenas (L.), along the Nova Scotian shore into the southeastern Gulf of St. Lawrence, Canada. J Shellfish Res 22, 255–262 (2003).

10.1098/rspb.2006.3597

10.1093/plankt/18.11.1981

10.1016/j.jmarsys.2006.11.007

10.1890/1051-0761(2003)013[0159:PDDATS]2.0.CO;2

10.1086/BBLv216n3p373

10.1175/1520-0485(1985)015<0713:TNSFEP>2.0.CO;2

G McMullin, Longshore momentum balance for a mid-shelf region of the Gulf of Maine using the Gulf of Maine Ocean Observing System. MA thesis (University of New Hampshire, Durham, NH, 2003).

10.1016/j.dsr2.2005.06.033

10.1016/j.dsr2.2006.08.015

10.1111/j.1472-4642.2010.00703.x

JW Loder, B Petrie, G Gawarkiewicz, The coastal ocean off northeastern North America: A large-scale view. The Sea 11, 105–133 (1998).

10.1146/annurev.ecolsys.39.110707.173414

S Schneider, D Roessli, L Excoffier Arlequin: A Software for Population Genetics Data Analysis (Genetics and Biometry Lab, University of Geneva, Geneva), Version 2,, pp. 2496–2497 (2000).

G Klassen, A Locke, A biological synopsis of the European green crab, Carcinus maenas. Can Manuscr Rep Fish Aquat Sci 2818, 1–75 (2007).

10.1007/s11538-006-9182-9

10.3354/meps07836

WH Press, SA Teukolsky, WT Vetterling, BP Flannery Numerical Recipes: The Art of Scientific Computing (Cambridge Univ Press, 3rd Ed, Cambridge, UK, 2007).

10.1175/1520-0485(2001)031<0591:SCOTWA>2.0.CO;2