Reconciling paleodistribution models and comparative phylogeography in the Wet Tropics rainforest land snail Gnarosophia bellendenkerensis (Brazier 1875)

doi:10.1073/pnas.092538699

Reconciling paleodistribution models and comparative phylogeography in the Wet Tropics rainforest land snail Gnarosophia bellendenkerensis (Brazier 1875)

^†Cooperative Research Centre for Tropical Rainforest Ecology and Management, Department of Zoology and Entomology, University of Queensland, Brisbane, Qld 4072, Australia; ^§Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA 94720-3160; and ^¶Queensland Centre for Biodiversity, Queensland Museum, Brisbane, Qld 4000, Australia

Edited by David B. Wake, University of California, Berkeley, CA, and approved February 8, 2002 (received for review October 10, 2001)

Abstract

Comparative phylogeography has proved useful for investigating biological responses to past climate change and is strongest when combined with extrinsic hypotheses derived from the fossil record or geology. However, the rarity of species with sufficient, spatially explicit fossil evidence restricts the application of this method. Here, we develop an alternative approach in which spatial models of predicted species distributions under serial paleoclimates are compared with a molecular phylogeography, in this case for a snail endemic to the rainforests of North Queensland, Australia. We also compare the phylogeography of the snail to those from several endemic vertebrates and use consilience across all of these approaches to enhance biogeographical inference for this rainforest fauna. The snail mtDNA phylogeography is consistent with predictions from paleoclimate modeling in relation to the location and size of climatic refugia through the late Pleistocene-Holocene and broad patterns of extinction and recolonization. There is general agreement between quantitative estimates of population expansion from sequence data (using likelihood and coalescent methods) vs. distributional modeling. The snail phylogeography represents a composite of both common and idiosyncratic patterns seen among vertebrates, reflecting the geographically finer scale of persistence and subdivision in the snail. In general, this multifaceted approach, combining spatially explicit paleoclimatological models and comparative phylogeography, provides a powerful approach to locating historical refugia and understanding species' responses to them.

Footnotes

↵ ‡ To whom reprint requests should be addressed. E-mail: ahugall{at}zen.uq.edu.au.
This paper was submitted directly (Track II) to the PNAS office.
Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. AY048376–AY048422).
Abbreviations:

WT,

Wet Tropics;

BMC,

Black Mountain Corridor;

Kya,

thousand years ago;

AMT,

annual mean temperature;

AMP,

annual mean precipitation;

PDQ,

precipitation of the driest quarter;

LGM,

last glacial maximum;

MT,

Malbon-Thompson Range;

BK,

Bellenden Ker;

AT,

Atherton Tableland;

FU,

Finnegan Uplands;

KU,

Kirrama Uplands;

AU,

Atherton Uplands;

TU,

Thornton Uplands;

CU,

Carbine Uplands;

LU,

Lamb Uplands;

WU,

Windsor Uplands