Fig 4. Ancestral state reconstructions of genome size, Dv, lg, and Ds through time for angiosperms (A; blue circles), gymnosperms (G; pink triangles), and ferns (F; grey squares).
Error bars around reconstructed values represent error due to phylogenetic uncertainty. The shaded timespan indicates the Cretaceous period, during which most major lineages of angiosperms diversified. Lines represent the best-fit models through the lower (genome size and lg) and upper (Dv and Ds) 10% of reconstructed values. For all traits, extreme trait values of angiosperms rapidly changed during the Cretaceous period, whereas fern and gymnosperm lineages underwent no such changes. (a) Genome size of ferns (genome size = 10.24; n = 51, df = 11, p < 0.001), gymnosperms (genome size = 19.46; n = 53, df = 13, p < 0.001), and angiosperms (genome size = 1.08 + 2.53/(1 + e^(−(time − 119.28) / 9.52; n = 289, df = 20, p < 0.001). (b) Leaf Dv of ferns (Dv = 1.70; n = 10, df = 1, p < 0.01), gymnosperms (Dv = 1.74; n = 23, df = 9, p < 0.001), and angiosperms (Dv = 4.39 + 4.42 / (1 + e^(−[time − 125.32] / [−8.22]), n = 165, df = 17, p < 0.001). (c) lg of ferns (lg = 43.04; n = 38, df = 12, p < 0.001), gymnosperms (lg = 55.48; n = 20, df = 8, p < 0.001), and angiosperms (lg = 26.93 + 10.58 / (1 + e^(−[time − 119.73] / 6.12); n = 184, df = 16, p < 0.001. (d) Ds of ferns (Ds = 1.80; n = 26, df = 2, p < 0.001), gymnosperms (Ds = 1.94; n = 37, df = 11, p < 0.001), and angiosperms (Ds = 2.33 − 0.364 / (1 + e^(−[time − 121.65] / 17.39); n = 184, df = 15, p < 0.001). Marginal plots on the outside of each panel represent the median (points), interquartile ranges (solid lines), and ranges (dotted lines) of trait values for extant species. A, angiosperms; Ds, stomatal density; Dv, vein density; F, ferns; G, gymnosperms; lg, guard cell length.