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

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

JOURNAL OF NATURAL HISTORY

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2016 vol. 51 p. 17 - 32

0022-2933

This paper primarily aims to test a Pleistocene refuge-type scenario,as previously proposed for the gonyleptid Geraeocormobiussylvarum, a semi-deciduous forests dweller in subtropicalArgentina, Brazil and Paraguay. Palaeodistributional models ofthis species were built using MaxEnt for two Last GlacialMaximum (LGM = 21,000 years ago) simulations ? CommunityClimate System Model (CCSM) and Model for InterdisciplinaryResearch on Climate (MIROC) ? and for 6000 years ago(−6k = HCO, the Holocene climatic optimum). Both LGM modelsretrieved a fragmented pattern. For CCSM, range was split intomultiple, scattered fragments. MIROC resulted in very few patches,with a decided range reduction because of a strong humiditydrop. Models for −6k recovered a moderate range expansion. Nopast connection between the core area and the yungas was predicted.Analysis of variables importance showed that two precipitationpredictors (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 analysisrecognized them as limiting too, in different parts of the speciesrange. LGM palaeomodels of G. sylvarum are compatible with therefuge hypothesis invoked in previous molecular analyses, toexplain the high genetic diversity found in the core area.Additionally, the results reinforced the hypothesis of the recentanthropogenic origin of the yungas disjunct populations.