Table 1.
Intrageneric divergence times (million years) estimated for Fagus with the FBD model, using either each fossil's oldest stratigraphic age, youngest stratigraphic age, or a random age from in between. MRCA, most recent common ancestor; the Engleriana lineage includes the East/Northeast Asian species F. engleriana and F. japonica; the Fagus lineage includes the remaining living species. Stratigraphic ages are shown in electronic supplementary material, table S3.
| node | oldest stratigraphic age | random age in between | youngest stratigraphic age |
|---|---|---|---|
| MRCA of all extant species (=divergence of Engleriana and Fagus lineages) | 54.8 (65.7–46.4) | 52.5 (62.0–43.0) | 52.4 (77.8–36.2) |
| divergence of F. engleriana from F. japonica | 9.3 (21.2–1.9) | 9.5 (20.3–1.9) | 10.1 (42.1–0.6) |
| divergence of Pacific-North American lineage (F. grandifolia) from Fagus lineage | 47.5 (54.1–42.2) | 44.4 (50.8–39.1) | 43.6 (58.7–35.5) |
| first radiation within Eurasian clade, separation into East Asian and widespread Eurasian clade | 44.3 (49.8–40.2) | 41.5 (46.1–37.4) | 40.2 (52.9–34.9) |
| divergence of F. lucida from F. hayatae/F. longipetiolata | 40.5 (44.1–38.1) | 37.9 (41.3–35.8) | 36.6 (46.5–33.9) |
| divergence of F. hayatae from F. longipetiolata | 38.5 (40.6–37.8) | 35.9 (37.9–35.3) | 34.5 (41.3–33.9) |
| divergence of Japanese F. crenata from western Eurasian F. sylvatica s.l. | 27.1 (38.0–17.8) | 23.0 (34.9–13.9) | 23.2 (42.9–11.7) |
| divergence of F. orientalis (=F. sylvatica subsp. orientalis) from C. European F. sylvatica | 10.6 (21.1–2.6) | 8.7 (20.0–1.8) | 9.8 (34.8–0.6) |