The ghost of introduction past : spatial and temporal variability in the genetic diversity of invasive smallmouth bass
Date
2018
Journal Title
Journal ISSN
Volume Title
Publisher
Wiley Open Access
Abstract
Understanding the demographic history of introduced populations is essential for
unravelling their invasive potential and adaptability to a novel environment. To this
end, levels of genetic diversity within the native and invasive range of a species are
often compared. Most studies, however, focus solely on contemporary samples, relying
heavily on the premise that the historic population structure within the native
range has been maintained over time. Here, we assess this assumption by conducting
a three-way
comparison of the genetic diversity of native (historic and contemporary)
and invasive (contemporary) smallmouth bass (Micropterus dolomieu) populations.
Analyses of a total of 572 M. dolomieu samples, representing the contemporary
invasive South African range, contemporary and historical native USA range (dating
back to the 1930s when these fish were first introduced into South Africa), revealed
that the historical native range had higher genetic diversity levels when compared to
both contemporary native and invasive ranges. These results suggest that both contemporary
populations experienced a recent genetic bottleneck. Furthermore, the
invasive range displayed significant population structure, whereas both historical and
contemporary native US populations revealed higher levels of admixture. Comparison
of contemporary and historical samples showed both a historic introduction of M. dolomieu
and a more recent introduction, thereby demonstrating that undocumented
introductions of this species have occurred. Although multiple introductions might
have contributed to the high levels of genetic diversity in the invaded range, we discuss
alternative factors that may have been responsible for the elevated levels of
genetic diversity and highlight the importance of incorporating historic specimens
into demographic analyses.
Description
CITATION: Diedericks, G., et al. 2018. The ghost of introduction past : spatial and temporal variability in the genetic diversity of invasive smallmouth bass. Evolutionary Applications, 11(1):–1-21, doi:10.1111/eva.12652.
The original publication is available at http://onlinelibrary.wiley.com
Publication of this article was funded by the Stellenbosch University Open Access Fund.
The original publication is available at http://onlinelibrary.wiley.com
Publication of this article was funded by the Stellenbosch University Open Access Fund.
Keywords
Smallmouth bass, Introduced organisms
Citation
Diedericks, G., et al. 2018. The ghost of introduction past : spatial and temporal variability in the genetic diversity of invasive smallmouth bass. Evolutionary Applications, 11(1):–1-21, doi:10.1111/eva.12652