Résumé
The high degree of endemism on Sulawesi has previously been suggested to
have vicariant origins, dating back 40 Myr ago. Recent studies, however,
suggest that much of Sulawesi’s fauna assembled over the last 15 Myr.
Here, we test the hypothesis that more recent uplift of previously
submerged portions of land on Sulawesi promoted diversification, and that
much of its faunal assemblage is much younger than the island itself. To
do so, we combined palaeogeographical reconstructions with genetic and
morphometric data sets derived from Sulawesi’s three largest mammals: the
Babirusa, Anoa, and Sulawesi warty pig. Our results indicate that although
these species most likely colonized the area that is now Sulawesi at
different times (14 Myr ago to 2-3 Myr ago), they experienced an almost
synchronous expansion from the central part of the island. Geological
reconstructions indicate that this area was above sea level for most of
the last 4 Myr, unlike most parts of the island. We conclude that
emergence of land on Sulawesi (~1–2 Myr) may have allowed species to
expand synchronously. Altogether, our results indicate that the
establishment of the highly endemic faunal assemblage on Sulawesi was
driven by geological events over the last few million years.