Comparing the population history of Neotropical annual species: The role of climate change and hybridization between Tithonia tubaeformis and T. rotundifolia (Asteraceae)
Por:
Lopez-Caamal, A., Tovar-Sanchez, E.
Publicada:
1 nov 2021
Ahead of Print:
1 ago 2021
Resumen:
Historical climate changes and interspecific gene flow have played an
important role in shaping the distribution and genetic diversity of the
biota in the Neotropics. In this study, we explored the role of both the
Pleistocene climate changes and hybridization on the contemporary
geographic structure of two Neotropical weedy species: Tithonia
tubaeformis and T. rotundifolia. Distribution shifts under past and
current climate conditions were explored through ecological niche
modelling (ENM). We then tested these hypotheses using chloroplast
microsatellite (cpSSR) data in T. tubaeformis and compared the patterns
deduced with those previously reported for T. rotundifolia using the
same cpSSR loci. Lastly, we searched for shared haplotypes between
species. Both species exhibited significant downwards altitudinal shifts
during the last interglacial (LIG) and the Last Glacial Maximum (LGM).
For instance, T. rotundifolia showed large suitable habitat areas since
the LIG at xeric conditions in western Mesoamerica. Tithonia tubaeformis
showed a similar to five-fold range contraction during the LIG compared
to current climate conditions, followed by a range expansion in the LGM.
Despite the large shared refugial areas predicted through ENM, we found
a low number of shared haplotypes, suggesting a minor role of
hybridization in shaping the geographic structure of these species. Our
results provide additional patterns of the population history of the
northern Neotropics during the Quaternary, and we suggest that weedy
widespread species are a well-suited group for the study of the effects
of historic climatic changes on the biota of this region.
Filiaciones:
Lopez-Caamal, A.:
Univ Autonoma Estado Morelos, Ctr Invest Biodiversidad & Conservac, Cuernavaca, Morelos, Mexico
Tovar-Sanchez, E.:
Univ Autonoma Estado Morelos, Ctr Invest Biodiversidad & Conservac, Cuernavaca, Morelos, Mexico
(Corresponding Author), Univ Autonoma Estado Morelos, Ctr Invest Biodiversidad & Conservac, Cuernavaca, Morelos, Mexico
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