title: Recent and rapid population growth and range expansion of the Lyme disease tick vector, Ixodes scapularis, in North America.
abstract: Migration is a primary force of biological evolution that alters allele frequencies and introduces novel genetic variants into populations. Recent migration has been proposed as the cause of the emergence of many infectious diseases, including those carried by blacklegged ticks in North America. Populations of blacklegged ticks have established and flourished in areas of North America previously thought to be devoid of this species. The recent discovery of these populations of blacklegged ticks may have resulted from either in situ growth of long-established populations that were maintained at very low densities or by migration and colonization from established populations. These alternative evolutionary hypotheses were investigated using Bayesian phylogeographic approaches to infer the origin and migratory history of recently detected blacklegged tick populations in the Northeastern United States. The data and results indicate that newly detected tick populations are not the product of in situ population growth from a previously established population but from recent colonization resulting in a geographic range expansion. This expansion in the geographic range proceeded primarily through progressive and local migration events from southern populations to proximate northern locations although long-distance migration events were also detected.
authors.affiliation: University of Pennsylvania, Philadelphia, Pennsylvania, 19104. ckhatchikian@gmail.com.
authors.forename: Camilo E
authors.initials: CE
authors.lastname: Khatchikian
authors.affiliation: New York Department of Health, Albany, New York, 12237.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Prusinski
authors.affiliation: State University of New York, Albany, New York, 12222.
authors.forename: Melissa
authors.initials: M
authors.lastname: Stone
authors.affiliation: New York Department of Health, Albany, New York, 12237.|State University of New York, Albany, New York, 12222.
authors.forename: Peter Bryon
authors.initials: PB
authors.lastname: Backenson
authors.affiliation: State University of New York, Albany, New York, 12222.
authors.forename: Ing-Nang
authors.initials: IN
authors.lastname: Wang
authors.affiliation: University of Pennsylvania, Philadelphia, Pennsylvania, 19104.
authors.forename: Erica
authors.initials: E
authors.lastname: Foley
authors.affiliation: University of Pennsylvania, Philadelphia, Pennsylvania, 19104.
authors.forename: Stephanie N
authors.initials: SN
authors.lastname: Seifert
authors.affiliation: University of Pennsylvania, Philadelphia, Pennsylvania, 19104.
authors.forename: Michael Z
authors.initials: MZ
authors.lastname: Levy
authors.affiliation: University of Pennsylvania, Philadelphia, Pennsylvania, 19104. dbrisson@upenn.edu.
authors.forename: Dustin
authors.initials: D
authors.lastname: Brisson
mesh_terms: D063147:Animal Distribution; D000818:Animals; D001096:Arachnid Vectors / Q000235:genetics / Q000502:physiology*; D001499:Bayes Theorem; D051456:Gene Flow; D018884:Ixodes / Q000235:genetics / Q000502:physiology*; D008193:Lyme Disease / Q000382:microbiology / Q000635:transmission; D008969:Molecular Sequence Data; D009518:New York; D010802:Phylogeny; D058974:Phylogeography; D011158:Population Growth; D017422:Sequence Analysis, DNA
keywords: Blacklegged tick; emerging disease; phylogeography; zoonosis