title: Post-colonization temporal genetic variation of an introduced fly, Rhagoletis completa.
abstract: Evolutionary biologists have been puzzled by the success of introduced species: despite founder effects that reduce genetic variability, invasive species are still successful at colonizing new environments. It is possible that the evolutionary processes during the post-colonization period may increase the genetic diversity and gene flow among invasive populations over time, facilitating their long-term success. Therefore, genetic diversity and population structure would be expected to show greater temporal variation for successful introduced populations than for native populations. We studied the population genetics of the walnut husk fly, Rhagoletis completa, which was introduced into California from the Midwestern US in the early 1900s. We used microsatellites and allozymes to genotype current and historic fly populations, providing a rare perspective on temporal variability in population genetic parameters. We found that introduced populations showed greater temporal fluctuations in allele frequencies than native populations. Some introduced populations also showed an increase in genetic diversity over time, indicating multiple introductions had occurred. Population genetic structure decreased in both native and introduced populations over time. Our study demonstrates that introduced species are not at equilibrium and post-colonization processes may be important in ameliorating the loss of genetic diversity associated with biological invasions.
authors.affiliation: Environmental Science ESPM, University of California at Berkeley, 137 Mulford Hall #3114, Berkeley, CA 94720-3114, USA. Yolanda.Chen@uvm.edu
authors.forename: Yolanda H
authors.initials: YH
authors.lastname: Chen
authors.forename: Stewart H
authors.initials: SH
authors.lastname: Berlocher
authors.forename: Susan B
authors.initials: SB
authors.lastname: Opp
authors.forename: George K
authors.initials: GK
authors.lastname: Roderick
mesh_terms: D000818:Animals; D002140:California; D018703:Founder Effect; D051456:Gene Flow; D056426:Genetic Loci; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D058865:Introduced Species; D018895:Microsatellite Repeats; D033621:Tephritidae / Q000235:genetics*
references.citation: Oecologia. 2006 Oct;149(4):656-67
references.pmid: 16858586
references.citation: Genetica. 2007 Feb;129(2):127-32
references.pmid: 16924404
references.citation: Oecologia. 2005 Jun;144(1):1-11
references.pmid: 15891837
references.citation: Nature. 2004 Sep 9;431(7005):177-81
references.pmid: 15356629
references.citation: Evolution. 1975 Mar;29(1):1-10
references.pmid: 28563291
references.citation: Mol Ecol. 2005 Oct;14(12):3643-56
references.pmid: 16202086
references.citation: Evolution. 1989 Jan;43(1):223-225
references.pmid: 28568501
references.citation: Evolution. 1996 Aug;50(4):1512-1519
references.pmid: 28565724
references.citation: Genetics. 2005 May;170(1):1-4
references.pmid: 15914771
references.citation: Mol Ecol. 2003 Nov;12(11):3123-35
references.pmid: 14629391
references.citation: Genetics. 1978 Mar;88(3):633-42
references.pmid: 17248813
references.citation: Biochem Genet. 1970 Apr;4(2):297-320
references.pmid: 4193186
references.citation: J Econ Entomol. 1999 Apr;92(2):485-9
references.pmid: 10333755
references.citation: Heredity (Edinb). 1974 Oct;33(2):229-39
references.pmid: 4531429
references.citation: Evolution. 1984 Jul;38(4):906-918
references.pmid: 28555821
references.citation: Trends Ecol Evol. 2007 Sep;22(9):454-64
references.pmid: 17673331
references.citation: Nat Rev Genet. 2003 Nov;4(11):889-99
references.pmid: 14634636
references.citation: Proc Natl Acad Sci U S A. 2000 Jun 20;97(13):7043-50
references.pmid: 10860969
references.citation: Mol Ecol. 2000 May;9(5):615-28
references.pmid: 10792704
references.citation: Mol Ecol. 2008 Jan;17(1):431-49
references.pmid: 17908213
references.citation: Mol Ecol. 2002 Feb;11(2):197-214
references.pmid: 11856422
references.citation: Mol Ecol. 2005 Dec;14(14):4275-85
references.pmid: 16313592