Header

UZH-Logo

Maintenance Infos

Origins of endemic island tortoises in the western Indian Ocean: a critique of the human-translocation hypothesis


Hansen, Dennis M; Austin, Jeremy J; Baxter, Rich H; de Boer, Erik J; Falcón, Wilfredo; Norder, Sietze J; Rijsdijk, Kenneth F; Thébaud, Christophe; Bunbury, Nancy J; Warren, Ben H (2017). Origins of endemic island tortoises in the western Indian Ocean: a critique of the human-translocation hypothesis. Journal of Biogeography, 44(6):1430-1435.

Abstract

How do organisms arrive on isolated islands, and how do insular evolutionary radiations arise? In a recent paper, Wilmé et al. (2016a) argue that early Austronesians that colonized Madagascar from Southeast Asia translocated giant tortoises to islands in the western Indian Ocean. In the Mascarene Islands, moreover, the human-translocated tortoises then evolved and radiated in an endemic genus (Cylindraspis). Their proposal ignores the broad, established understanding of the processes leading to the formation of native island biotas, including endemic radiations. We find Wilmé et al.'s suggestion poorly conceived, using a flawed methodology and missing two critical pieces of information: the timing and the specifics of proposed translocations. In response, we here summarize the arguments that could be used to defend the natural origin not only of Indian Ocean giant tortoises but also of scores of insular endemic radiations world-wide. Reinforcing a generalist's objection, the phylogenetic and ecological data on giant tortoises, and current knowledge of environmental and palaeogeographical history of the Indian Ocean, make Wilmé et al.'s argument even more unlikely.

Abstract

How do organisms arrive on isolated islands, and how do insular evolutionary radiations arise? In a recent paper, Wilmé et al. (2016a) argue that early Austronesians that colonized Madagascar from Southeast Asia translocated giant tortoises to islands in the western Indian Ocean. In the Mascarene Islands, moreover, the human-translocated tortoises then evolved and radiated in an endemic genus (Cylindraspis). Their proposal ignores the broad, established understanding of the processes leading to the formation of native island biotas, including endemic radiations. We find Wilmé et al.'s suggestion poorly conceived, using a flawed methodology and missing two critical pieces of information: the timing and the specifics of proposed translocations. In response, we here summarize the arguments that could be used to defend the natural origin not only of Indian Ocean giant tortoises but also of scores of insular endemic radiations world-wide. Reinforcing a generalist's objection, the phylogenetic and ecological data on giant tortoises, and current knowledge of environmental and palaeogeographical history of the Indian Ocean, make Wilmé et al.'s argument even more unlikely.

Statistics

Altmetrics

Downloads

1 download since deposited on 16 Jan 2017
1 download since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, further contribution
Communities & Collections:07 Faculty of Science > Department of Systematic and Evolutionary Botany
07 Faculty of Science > Zurich-Basel Plant Science Center
Dewey Decimal Classification:580 Plants (Botany)
Language:English
Date:2017
Deposited On:16 Jan 2017 15:36
Last Modified:08 Dec 2017 22:19
Publisher:Wiley-Blackwell Publishing, Inc.
ISSN:0305-0270
Additional Information:This is the peer reviewed version of the following article: Journal of Biogeography, which has been published in final form at https://doi.org/10.1111/jbi.12893. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving (http://olabout.wiley.com/WileyCDA/Section/id-820227.html#terms).
Publisher DOI:https://doi.org/10.1111/jbi.12893

Download

Download PDF  'Origins of endemic island tortoises in the western Indian Ocean: a critique of the human-translocation hypothesis'.
Preview
Content: Accepted Version
Filetype: PDF
Size: 351kB