On the Environment of Aramis

Abstract

The responses ofWhite (2014) and Suwa and Ambrose (2014) do not fully address our comment (Cerling, Brown, andWynn 2014), which concerned four issues, as follows: 1. White (in his comment in Dominguez-Rodrigo 2014) misrepresents our position on the environment of Ardipithecus. White (in Dominguez-Rodrigo 2014) states that Cerling et al. (2010, 2011) “parsed Ardipithecus habitat as grassland,” whereas Cerling et al. (2010) state that “open savanna grassland was not the environmental context of Ardipithecus.” 2. White (in Dominguez-Rodrigo 2014) suggests that our previous analysis was “flawed by biased standards” and that a different subset of data would give quite different results. In our comment (Cerling, Brown, and Wynn 2014), we show that all suggested subsets of the modern soil proxy data show that the predominant biome at Aramis is “wooded grassland,” using the UNESCO classification for Africa vegetation (White 1983). 3. White (in Dominguez-Rodrigo 2014) use colobine isotope data to emphasize the importance of closed canopy and forested habitats at Aramis. The isotope data on colobines provide a baseline for the diet of a pure C3 folivore primate with which to compare Ardipithecus. White et al. (2009) previously asserted that both Pliopapio and Ardipithecus had diets with minor, but significant, percentages of C4-derived resources. C4 dietary resources are obtained in more open environments, not forest, as pointed out by White et al. (2009: 14–15, supplementary information). The origin of the C4 component of Ardipithecus diet is of high importance in understanding the evolution and ecology of this species. 4. White and coauthors had previously interpreted fluviatile deposition at Aramis (WoldeGabriel et al. 2009) but later claimed that there is no evidence for fluviatile deposition at Aramis (Ambrose, WoldeGabriel, and White 2011).