Fig. 2
Evolution of extant Gephyrocapsa species. a Phylogenetic chronogram of extant Gephyrocapsa based on analysis of genome sequence data of 10 strains. 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 2; uniform prior 290–350 ka) in the fossil record. 95% Highest posterior density (HPD) intervals for ages are shown as grey bars. b Densitree plot based on 6278 phylogenies constructed for genomic fragments 10 kb long, and consensus species tree of extant Gephyrocapsa inferred from a multi coalescent method. All nodes are supported with 100% bootstrap. c Demographic modelling of Gephyrocapsa speciation history. The sizes of blue circles are proportional to estimated population sizes of extant and ancestral Gephyrocapsa species; the numbers inside blue circles (=θ/θGhux) show population sizes relative to that in extant G. huxleyi. Direction of inferred interspecific gene flow is shown with purple arrows, with their widths and the number next to arrowhead showing gene flow intensity per generation. For estimates with confidence intervals see Supplementary Tables 2 and 3. d Stacked relative abundance of the Noëlaerhabdaceae assemblage including Gephyrocapsa and Reticulofenestra species over the last ~700 ka at site 108288 (Large Gephyrocapsa include G. oceanica; Medium, G. margereli and G. muellerae; Small, G. aperta and G. ericsonii). e Absolute number of the same assemblage in site 1082. f Global Δ sea surface temperature (ΔSST) over 700 ka52, blue line is for mean variations, red and blue bands for 95% confidence intervals (respectively variability and jackknife). Red line corresponds to loess smoothing and associated grey band to 95% confidence interval
