title: Colonization history and population genetics of the color-polymorphic Hawaiian happy-face spider Theridion grallator (Araneae, Theridiidae).
abstract: Past geological and climatological processes shape extant biodiversity. In the Hawaiian Islands, these processes have provided the physical environment for a number of extensive adaptive radiations. Yet, single species that occur throughout the islands provide some of the best cases for understanding how species respond to the shifting dynamics of the islands in the context of colonization history and associated demographic and adaptive shifts. Here, we focus on the Hawaiian happy-face spider, a single color-polymorphic species, and use mitochondrial and nuclear allozyme markers to examine (1) how the mosaic formation of the landscape has dictated population structure, and (2) how cycles of expansion and contraction of the habitat matrix have been associated with demographic shifts, including a "quantum shift" in the genetic basis of the color polymorphism. The results show a marked structure among populations consistent with the age progression of the islands. The finding of low genetic diversity at the youngest site coupled with the very high diversity of haplotypes on the slightly older substrates that are highly dissected by recent volcanism suggests that the mosaic structure of the landscape may play an important role in allowing differentiation of the adaptive color polymorphism.
authors.affiliation: Department of Environmental Science, Policy, and Management, 130 Mulford Hall, University of California, Berkeley, California 94720-3114, USA. croucher@berkeley.edu
authors.forename: Peter J P
authors.initials: PJ
authors.lastname: Croucher
authors.forename: Geoff S
authors.initials: GS
authors.lastname: Oxford
authors.forename: Athena
authors.initials: A
authors.lastname: Lam
authors.forename: Neesha
authors.initials: N
authors.lastname: Mody
authors.forename: Rosemary G
authors.initials: RG
authors.lastname: Gillespie
mesh_terms: D000220:Adaptation, Biological; D000483:Alleles; D025041:Animal Migration; D000818:Animals; D005075:Biological Evolution; D004272:DNA, Mitochondrial; D005260:Female; D018703:Founder Effect; D005843:Geography; D006239:Haplotypes; D006254:Hawaii; D007527:Isoenzymes; D008297:Male; D008969:Molecular Sequence Data; D058974:Phylogeography; D010858:Pigmentation / Q000235:genetics*; D011110:Polymorphism, Genetic; D011157:Population Dynamics; D013112:Spiders / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial; D007527:Isoenzymes