Evolution of Biodiversity on the Sunda Shelf

Sundaland is the biogeographic region in southeast Asia which includes peninsular Malaysia and numerous nearby islands including Borneo, Sumatra and Java, but not Sulawesi or the Philippines. This region has been connected by dry land during much of the last few million years at times when the sea level was lower. This region is also very active tectonically and has many volcanoes and high mountains of a variety of heights including mountains over 2000 meters on all of the major land masses (Malay Peninsula, Sumatra and Borneo). This region is covered in tropical forest and is considered a hotspot because of its immense biodiversity. This diversity inspired A.R. Wallace with one of the greatest basic insights in the field of evolutionary biology that led him to propose the concept of speciation via natural selection around the same time that the Neotropics inspired C. Darwin to come up with very similar ideas. We also study this biodiversity in order to better understand evolution.

We are studying a variety of vertebrates, especially forest dependent mammals and barbets. We are constructing phylogenies of endemic taxa and using those phylogenies to better understand how the tropical biodiversity evolved and is maintained, to understand the biology of the animals, and to identify problematic taxonomic issues.

At the moment we are focusing on divergence along altitudinal gradients, adaptation to high altitude, population diversity and divergence in high altitude species, and taxonomic revisions.

In order to study these changes with altitude we mount expeditions to trap small mammals along altitudinal transects. Jennifer Leonard is now on expedition! You can follow it here. Miguel Camacho and Arlo Hinckley Boned have been in the expeditions, sampling and discovering new species ranges. You can follow their adventure in the blog Small Mammals of Borneo or in theexpedition Facebook page.

Three last photos by Daniel Hinckley and Arlo Hinckley. All rights reserved.

Jennifer Leonard is leading this project, which is a collaborative effort.

Past students:
Arlo Hinckley Boned, PhD: "Habitat driven diversification in small mammals of tropical east Asia", University of Seville, Seville, Spain, 2021.
Miguel Camacho, PhD: "Evolution in Sundaland: insights from comparative phylogeography of Rattus and Sundamys rats", Pablo de Olavide University, Seville, Spain, 2017.
 Robert-Jan den Tex, PhD: "Patterns and Processes of Evolution in Sundaland", Uppsala University, Sweden, 2011.
Irene Quintanilla, Masters in Biodiversity and Biological Conservation: "Genetic diversity of Rattus baluensis in Kinabalu Park mountains",
  University Pablo de Olavide, Seville, Spain, 2015.
Melissa TR Hawkins, PhD: “Diversification of tree squirrels and tree shrews in Sundaland,” George Mason University, United States, 2015
  (co-advisor with Jesus Maldonado)

Some of our collaborators are:
Jesus Maldonado, Smithsonian Institution
Faisal Khan, University Malaysia Sarawak
Noor Haliza binti Hasan, Institute for Tropical Biology & Conservation, University Malaysia Sabah
Hasmahzaiti binti Omar, University Malaysia

Related peer-reviewed articles

Challenging ecogeographical rules: Phenotypic variation in the Mountain Treeshrew (Tupaia montana) along tropical elevational gradients Hinckley A, Sanchez-Donoso I, Comas M, Camacho-Sanchez M, Hawkins MTR, Hasan NH, Leonard JA (2022) PLoSONE 17(6):e0268213		Link
Interglacial refugia on tropical mountains: Novel insights from the summit rat (Rattus baluensis), a Borneo mountain endemic Camacho-Sanchez M, Quintanilla I, Hawkins MTR, Tuh FYY, Wells K, Maldonado JE, Leonard JA (2018) Diversity and Distributions. doi: 10.1111/ddi.12761		Link
The generic status of Rattus annandalei (Bonhote, 1903) (Rodentia, Murinae) and its evolutionary implications Camacho-Sanchez M, Leonard JA , Fitriana Y, Tilak M-K, Fabre P-H (2017) Journal of Mammalogy 38(5), 1340-1355

Hawkins MTR, Leonard JA, Helgen KM, McDonough MM, Rockwood LL, Maldonado JE (2016) Evolutionary history of endemic Sulawesi squirrels constructed from UCEs and mitogenomes sequenced from museum specimens. BMC Evolutionary Biology 16: 80.
DOI: 10.1186/s12862-016-0650-z Link

Hawkins MTR, Helgen KM, Maldonado JE, Rockwood LL, Tsuchiya MTN, Leonard JA (2016) Phylogeny, biogeography and systematic revision of plain long-nosed squirrels (genus Dremomys, Nannosciurinae). Molecular Phylogenetics and Evolution 94: 752-764.
DOI:10.1016/j.ympev.2015.10.023

Leonard JA, den Tex R-J, Hawkins MTR, Muñoz-Fuentes V, Thorington R, Maldonado JE (2015) Phylogeography of vertebrates on the Sunda Shelf: a multi-species comparison. Journal of Biogeography 42: 871-879. .

den Tex R-J & Leonard JA (2014) The phylogeography of red and yellow coppersmith barbets (Aves: Megalaima haemacephala). Frontiers in Ecology and Evolution, 2: 00016. doi: 10.3389/fevo.2014.00016 Link

den Tex R, Leonard JA (2013) A molecular phylogeny of Asian barbets: Speciation and extinction in the tropics. Molecular Phylogenetics and Evolution 68: 1-13

Gonzalez-Voyer A, den Tex R, Castello A, Leonard JA (2013) Evolution of acoustic and visual signals in Asian barbets. Journal of Evolutionary Biology 26: 647-659

Den Tex R, Thorington R, Maldonado JE, Leonard JA (2010) Speciation dynamics in the SE Asian tropics: putting a time perspective on the phylogeny and biogeography of Sundaland tree squirrels, Sundasciurus. Molecular Phylogenetics and Evolution 55, 711-720

Funding

CGL2010-21524 and CGL2014-58793-P