Fig. 3: Tempo of diversification between and within lineages in G. huxleyi.

a Phylogenetic chronogram of G. huxleyi based on analysis of genome sequence data of 63 strains. The phylogeny was rooted using one strain of G. muellerae and three strains of G. ericsonii/parvula as an outgroup. Every node in the phylogeny has a posterior probability at 1. The dating of ancestral nodes is based on relaxed molecular clock calibrated with the first appearance of G. huxleyi (node 1; 290 ka) in the fossil record. Details for nodes are reported in Supplementary Table S7. 95% Highest posterior density intervals for ages are shown as grey bars. b Visual representation of the parameters inferred for consecutive speciation events between lineages A1, A2 and B. Circles reflects effective population size (Ne) estimated for extant and ancestral species, on nodes and on leaves. Node 2 and 4 are highlighted in bold for correspondence with the chronogram. Divergence time are provided as an interval accounting for μ (=mutation rate) uncertainty [86]. Arrows represent secondary contact events with migration values in italic. All parameter estimates are listed in Supplementary Table 9. g: generation time. c Absolute abundance of G. huxleyi in sites U1475 [87] and SO139-74KL [88]. d Global Δ Sea Surface Temperature [89] (ΔSST; blue line) and LR04 [90] (red line) over 350 ka; (MIS: Marine Isotopic Stage).