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The impact of early Quaternary climate change on the diversification and population dynamics of a South American cactus species
Author(s) -
Silva Gislaine Angélica Rodrigues,
Antonelli Alexandre,
Lendel Anita,
Moraes Evandro de Marsola,
Manfrin Maura Helena
Publication year - 2018
Publication title -
journal of biogeography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 158
eISSN - 1365-2699
pISSN - 0305-0270
DOI - 10.1111/jbi.13107
Subject(s) - last glacial maximum , quaternary , population , pleistocene , ecology , climate change , phylogeography , species distribution , geography , interglacial , glacial period , biology , paleontology , phylogenetics , demography , habitat , biochemistry , sociology , gene
Aim Climatic oscillations have been suggested to promote speciation and changes in species distributions, mostly in connection with the Last Glacial Maximum ( LGM ). However, the LGM is just the most recent of the 20+ glacial‐interglacial periods that characterise the Quaternary. Here, we investigate the role of climatic changes and geomorphological features in shaping the evolution, distribution and population dynamics of the South American cactus Cereus hildmannianus . Location South‐eastern South America. Methods We built a large fossil‐calibrated phylogeny for cacti (family Cactaceae), comprising 128 species distributed in all subfamilies, using a Bayesian relaxed clock. We used the results to derive a secondary calibration for a population‐level phylogeny in C. hildmannianus . We amplified two plastid ( trnQ‐5′rps16 and psbJ‐petA ) and one nuclear marker ( PhyC ) for 24 populations. We estimated population dynamics, ancestral areas, and species distribution models to infer the clade's evolutionary history in time and space. Results Our results show a major population divergence of C. hildmannianus at c . 2.60 Ma, which is strikingly coincident with the transition of the Pliocene–Pleistocene and onset of Quaternary glaciations. This was followed by a complex phylogeographic scenario involving population expansions across ecologically diverse regions. Main conclusions Contrary to the dominant research focus on the LGM , our study indicates a major impact of the first Quaternary glaciation on the distribution and population divergence of a South American plant species. Further intraspecific events seem related to successive climatic changes and geomorphology, including the development of the coastal plain and its peculiar diversity. We propose that the first Quaternary glaciation acted as a major evolutionary bottleneck, whereby many warm‐adapted lineages succumbed, while those that survived could diversify and better cope with subsequent climatic oscillations.