Volcanism and palaeoclimate change drive diversification of the world's largest whip spider (Amblypygi)
Por:
Schramm, Frederic D., Valdez-Mondragon, Alejandro, Prendini, Lorenzo
Publicada:
1 jun 2021
Ahead of Print:
1 may 2021
Resumen:
The tropics contain many of the most biodiverse regions on Earth but the
processes responsible for generating this diversity remain poorly
understood. This study investigated the drivers of diversification in
arthropods with stenotopic ecological requirements and limited dispersal
capability using as a model the monotypic whip spider (Amblypygi) genus
Acanthophrynus, widespread in the tropical deciduous forests of Mexico.
We hypothesized that for these organisms, the tropical deciduous forests
serve as a conduit for dispersal, with their disappearance imposing
barriers. Given that these forests are located in a region of complex
geological history and that they fluctuated in extent during the
Pliocene-Pleistocene glacial/interglacial cycles we combine molecular
divergence dating, palaeoclimatic niche modelling and ancestral area
reconstruction to test if and when habitat fragmentation promoted
diversification in Acanthophrynus. Concomitant with the expected role of
landscape change, we demonstrate that orogeny of the Trans-Mexican
Volcanic Belt, in the Late Miocene or Early Pliocene (6.95-5.21 million
years ago), drove the earliest divergence of Acanthophrynus by
vicariance. Similarly, as expected, the later onset of glaciations
strongly impacted diversification. Whereas a more stable climate in the
southern part of the distribution enabled further diversification, a
marked loss of suitable habitat during the glaciations only allowed
dispersal and diversification in the north to occur later, resulting in
a lower overall diversity in this region. Barriers and diversification
patterns identified in Acanthophrynus are reflected in the
phylogeography of codistributed vertebrates and arthropods, emphasizing
the profound impact of Trans-Mexican Volcanic Belt orogeny and
glacial/interglacial cycles as drivers of diversification in the Mexican
Neotropics.
Filiaciones:
Amer Museum Nat Hist, Div Invertebrate Zool, Arachnol Lab, New York, NY 10024 USA
Univ Nacl Autonoma Mexico, Inst Biol, Lab Reg Biodiversidad & Cult Tejidos Vegetales LB, Lab Arachnol LATLAX, Tlaxcala, Mexico
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