Synchronous diversification of Sulawesi’s iconic artiodactyls driven by recent geological events

Abstract

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 recent uplift of previously submerged portions of land on Sulawesi promoted diversification, and that much of the 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 recent emergence of land on Sulawesi (~1-2 Myr) may have allowed species to expand synchronously. Altogether, our results indicates that the establishment of the highly endemic faunal assemblage on Sulawesi was driven by geological events over the last few million years.

geoorigins: A new method and r package for trait mapping and geographic provenancing of specimens without categorical constraints

“…As these distances are spatial, g 1 , …, g n are estimations of distances across the curved surface of the Earth and should be calculated using the haversine formula (Robusto, 1957). Elements of this matrix A are populated by calculating the correlation coefficient (either Spearman's rho or Pearson's r , depending on assumptions of linearity; see Section in Supporting Information) for the correlation between these spatial distances ( g ) and trait distances ( d ; Figure 1, following the correlation plotting method described in Frantz et al., 2018):…”

“…Such studies include exploring human‐mediated translocation and/or natural dispersal of organisms (e.g. Cucchi, 2008; Cucchi et al., 2014; Frantz et al., 2018; Lachlan et al., 2013) and establishing the geographic origin of human‐introduced invasive and commensal species (e.g. Gargan et al., 2016; Hooten & Wikle, 2008; Hunt et al., 2018; Jones, Eager, Gabriel, Jóhannesdóttir, & Searle, 2013).…”

Do Pleistocene rock paintings depict Sulawesi warty pigs (Sus celebensis) with a domestication character?

“…Sulawesi is the largest island in Wallacea, the biogeographically distinct zone of oceanic islands between continental Asia and Australia (Figure 1). The faunal history of Sulawesi is marked by a complex pattern of overwater dispersal events and insular evolution (Frantz et al ., 2018), giving rise to a mammalian fauna that is characterised by an exceptionally high rate of species endemism; essentially all of the island's species of terrestrial mammals occur nowhere else – bats are the only class of mammal that does (Evans, 2012; Groves, 1976; Holt et al ., 2012; Musser, 1987). The largest still‐extant non‐flying land mammals comprise anoas (Burton et al ., 2005; Groves, 1969; Groves & Grubb, 2011) and two suid genera: Babyrousa spp.…”

Floristics of forests across low nutrient soils in Sulawesi, Indonesia

“…In other parts of the world, the stressful soil types found in Sulawesi harbor many endemic species (Anacker, 2011; Cowling & Holmes, 1992; Fine & Baraloto, 2016). Furthermore, zoological endemism in Sulawesi has a marked spatial influence (Evans et al, 2003), that most obviously correlates with the formation of the island (Frantz et al, 2018). Sulawesi formed from an agglomeration of a number of different proto‐islands within the last 20 million years (Nugraha & Hall, 2018).…”