Kevin M. Purcell

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Understanding the introduction history and the impact of founder events on invasive species is crucial to understanding the evolutionary mechanisms driving successful invasions. Recently, there has been increased discussion of the “paradox” of invasions, the high success of introduced populations that presumably have limited genetic diversity associated(More)
Relative sea-level rise is resulting in the intrusion of saline waters into marshes historically dominated by fresh water. Saltwater intrusions can potentially affect resident marsh species, especially when storm-related tidal surges cause rapid changes in salinity. We examined the role of historical salinity exposure on the survival of Gambusia affinis(More)
Children from South Texas were evaluated for immu-noglobulin G to Rickettsia typhi, the causative agent of mu-rine typhus. Of 513 children, 8.6% of those 1–5 years of age, 13.3% of those 6–11 years of age, and 13.8% of those 12–17 years of age had positive results. R ickettsia typhi causes murine typhus in humans, a fe-brile illness with headache and rash.(More)
The evolutionarily significant unit concept provides a powerful tool for conserving biodiversity below the species level, but temporal criteria are often used explicitly or implicitly in the operational definitions of evolutionarily significant units (ESUs). Such temporal considerations have important implications for recently diverged taxa, as is the case(More)
The efficacy of invasive species management is dependent on a thorough understanding of the size, origin, and genetic structure of invasive populations. We evaluated the genetic diversity and structure of the western mosquitofish, Gambusia affinis, across the North Island of New Zealand in an effort to better understand the genetic structure and(More)
Technical Memoranda are used for documentation and timely communication of preliminary results, interim reports, or special-purpose information. Although the memoranda are not subject to complete formal review, they are expected to reflect sound professional work. ii NOTICE The National Marine Fisheries Service (NMFS) does not approve, recommend or endorse(More)
Although hurricanes have been implicated in causing shifts in waterbird use of individual colonies, little is known about whether or not these effects are consistent across broader areas affected by a storm. We examined the effects of Hurricane Rita, and to a lesser extent Katrina, and a subsequent drought, on the nesting activity of waterbirds across(More)
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