کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2835979 1164359 2006 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
E Pluribus Unum: A phylogenetic and phylogeographic reassessment of Laevapex (Pulmonata: Ancylidae), a North American genus of freshwater limpets
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک بوم شناسی، تکامل، رفتار و سامانه شناسی
پیش نمایش صفحه اول مقاله
E Pluribus Unum: A phylogenetic and phylogeographic reassessment of Laevapex (Pulmonata: Ancylidae), a North American genus of freshwater limpets
چکیده انگلیسی

The North American freshwater limpet genus Laevapex ( Walker, 1903) is a ubiquitous inhabitant of lentic and slow-moving lotic habitats east of the Rocky Mountains, but uncertainty clouds its systematic affinities, the phylogenetic validity of its constituent nominal species, and its degree of genetic connectivity among drainages. We addressed these issues by sampling the genus throughout much of its collective range and constructing representative nuclear and mitochondrial (mt) gene trees, in addition to performing morphometric analyses of shell shape variation. Our results identify neotropical Gundlachia and South American Uncancylus as sister lineages for Laevapex and reveal a pronounced sub-familial dichotomy within the Ancylidae, separating these three New World genera from a Holarctic (Ferrissia (Ancylus, Rhodacmea)) sister clade. Five nominal taxa (L. fuscus, L. diaphanus, L. peninsulae, L. sp., and “F.” arkansasensis), indistinguishable in our morphometric analyses, were polyphyletic in the mt gene trees, exhibited modest levels (<3.9%) of genetic divergence in the primary (103 of 109 individuals) mt clade and, with one minor exception, they appeared fixed for a single nuclear ITS-2 genotype. Although complicated by the presence of rare, highly divergent mt lineages (of either introgressive or persistent ancestral polymorphic origin) in some populations, the molecular data were consistent with a taxonomic conclusion that these five nominal taxa represent a single polymorphic lineage of the type species L. fuscus. AMOVA analyses indicated that 56% of the observed mt variation could be attributed to among population differences, only two of 36 haplotypes were detected in more than one sampling location, and estimates of among-population mt gene flow were generally low at both regional and continental scales. Unrooted network analyses revealed a number of mt tip clades, one restricted to the southwestern part of the range, the remainder having overlapping distributions in eastern North America. All of the eastern tip clades occurred in the Mid-Atlantic region, and these samples displayed by far the highest levels of collective mt diversity. However, directional gene flow estimates indicated that this region has been a recipient (especially from Alabama populations), rather than a source of haplotypic diversity, implying that it likely represents a center of overlap, not a primary ice age refugium, for this limpet species.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Molecular Phylogenetics and Evolution - Volume 40, Issue 2, August 2006, Pages 501–516
نویسندگان
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