Palaeoclimatic distribution models predict Pleistocene refuges for the Neotropical harvestman Geraeocormobius sylvarum (Arachnida, Opiliones, Gonyleptidae)

ACOSTA, L.E.; VASCHETTO, L.M.B.

JOURNAL OF NATURAL HISTORY

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2016 p. 1 - 16

0022-2933

This paper is primarily aimed to test a Pleistocene refuge-type scenario, as previously proposed for the gonyleptid Geraeocormobius sylvarum, a semideciduous forests dweller in subtropical Argentina, Brazil and Paraguay. Palaeodistributional models of this species were built using MaxEnt for two Last Glacial Maximum (LGM = 21000 ya = -21k) simulations, CCSM (Community Climate System Model) and MIROC (Model for Interdisciplinary Research on Climate), and for 6000 ya (-6k = HCO, Holocene climatic optimum). Both LGM models retrieved a fragmented pattern. For CCSM, range is was split in multiple, scattered fragments. MIROC resulted in very few patches, with a decided range reduction because of strong humidity drop. Models for -6k recovered a moderate range expansion. No past connection between the core area and the yungas was predicted. Analysis of variables importance showed that two precipitation (bc18 ? precipitation warmest quarter; bc14 ? precipitation driest month) and two temperature predictors (bc7 ? temperature annual range; bc9 ? mean temperature driest quarter) scored as the most influencing overall. The Limiting Factor analysis recognized them as limiting too, in different parts of the species range.LGM palaeomodels of G. sylvarum are compatible with the refuge hypothesis invoked in previous molecular analyses, to explain the high genetic diversity found in the core area. Additionally, results reinforced the hypothesis of recent anthropogenic origin of the yungas disjunct populations.