Figure 1.

The Pooideae phylogeny, present temperature data for focal species, and paleotemperature. A, Schematic phylogeny of the study species. The species phylogeny and dates are inferred from Schubert et al. (2018), except for B. sylvaticum, which was not included in the study. Placement and divergence date for B. sylvaticum are thus approximate. B, The range of the minimum temperature of the coldest month (WorldClim v1.4 data set, Bioclim variable 6, 2.5 km² resolution [Hijmans et al., 2005]) of the species geographical distribution (Global Biodiversity Information Facility, 2018). C, Oxygen isotope ratios as a proxy for historical global temperature (Zachos et al., 2001; Mudelsee et al., 2014). The transition between the Eocene and the Oligocene is shaded. Mya, Million years ago.