Title:

Footprints in the sand: independent reduction of subdigital lamellae in the Namib–Kalahari burrowing geckos

Author(s):
Publication Year:
2006
Abstract:

Many desert organisms exhibit convergence, and certain physical factors such as windblown sands have generated remarkably similar ecomorphs across divergent lineages. The burrowing geckos Colopus, Chondrodactylus and Palmatogecko occupy dune ecosystems in the Namib and Kalahari deserts of southwest Africa. Considered closely related, they share several putative synapomorphies, including reduced subdigital pads (toe pads) and spinose digital scales. Though recognized as part of Africa's ecologically diverse Pachydactylus Group, the burrowing geckos' precise phylogenetic affinities remain elusive. Convergent pedal modification provides a tenable alternative explaining the geckos' derived terrestriality and adaptation to Namib and Kalahari sands. We generated a molecular phylogeny for the Pachydactylus Group to examine evolutionary relationships among the burrowing geckos and infer historical patterns of pedal character change. Bayesian and parsimony analyses revealed all three burrowing genera to be deeply nested within Pachydactylus, each genus belonging to a separate clade. Strong support for these distinct clades indicates ecomorphological adaptations for burrowing have evolved independently three times in the southern Pachydactylus Group. We argue that the physical properties of Namib and Kalahari sands played a principal role in selecting for pedal similarity. Keywords: Keywords: convergence, ecomorphology, Gekkonidae, phylogenetics, Namib, Kalahari.

Publication Title:

Proceedings of the Royal Society B: Biological Sciences

Volume:
273
Issue:
1588
Pages:
855-864
Item Type:
Journal Article
Language:
en
Files:
Attachment Size
Footprints in the sand.pdf 257.45 KB

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