Post-colonization temporal genetic variation of an introduced fly, Rhagoletis completa.
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.
Chen
Yolanda H
YH
Environmental Science ESPM, University of California at Berkeley, 137 Mulford Hall #3114, Berkeley, CA 94720-3114, USA. Yolanda.Chen@uvm.edu
Berlocher
Stewart H
SH
Opp
Susan B
SB
Roderick
George K
GK
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*
Oecologia. 2006 Oct;149(4):656-67
16858586
Genetica. 2007 Feb;129(2):127-32
16924404
Oecologia. 2005 Jun;144(1):1-11
15891837
Nature. 2004 Sep 9;431(7005):177-81
15356629
Evolution. 1975 Mar;29(1):1-10
28563291
Mol Ecol. 2005 Oct;14(12):3643-56
16202086
Evolution. 1989 Jan;43(1):223-225
28568501
Evolution. 1996 Aug;50(4):1512-1519
28565724
Genetics. 2005 May;170(1):1-4
15914771
Mol Ecol. 2003 Nov;12(11):3123-35
14629391
Genetics. 1978 Mar;88(3):633-42
17248813
Biochem Genet. 1970 Apr;4(2):297-320
4193186
J Econ Entomol. 1999 Apr;92(2):485-9
10333755
Heredity (Edinb). 1974 Oct;33(2):229-39
4531429
Evolution. 1984 Jul;38(4):906-918
28555821
Trends Ecol Evol. 2007 Sep;22(9):454-64
17673331
Nat Rev Genet. 2003 Nov;4(11):889-99
14634636
Proc Natl Acad Sci U S A. 2000 Jun 20;97(13):7043-50
10860969
Mol Ecol. 2000 May;9(5):615-28
10792704
Mol Ecol. 2008 Jan;17(1):431-49
17908213
Mol Ecol. 2002 Feb;11(2):197-214
11856422
Mol Ecol. 2005 Dec;14(14):4275-85
16313592