Table 1.

Percentage of sequence identity of PsaA and PsaB in various species.

Pairs of relationships	Approximated divergence timea (Ma)	Sequence Identity (%)
		A vs A	B vs B
Arabidopsis thaliana vs Populus trichocarpa	104.6	98.6	98.2
Chloranthus spicatus vs Liriodendron tulipifera	173.2	99.2	99.1
A. thaliana vs C. spicatus	186.2	96.9	97.6
A. thaliana vs Illicium oligandrum	186.2	96.6	97.5
A. thaliana vs Nymphaea alba	186.2	97.3	97.1
A. thaliana vs Amborella trichopoda	186.2	96.6	96.4
Welwitschia mirabilis vs Pinus thunbergii	215.65	92.1	93.1
W. mirabilis vs Ginkgo biloba	236.75	92.8	94.0
W. mirabilis vs Cycas taitungensis	336.5	92.4	94.5
A. thaliana vs Psilotum nudum	421.1	91.0	91.1
A. thaliana vs Anthoceros formosae	731.2	91.4	91.4
A. thaliana vs Physcomitrella patens	731.2	92.4	92.5
A. thaliana vs Marchantia polymorpha	745.5	92.5	92.5
A. thaliana vs Cyanidioschyzon merolae	∼1100 to ∼1800b	82.2	80.9
A. thaliana vs Gloeobacter kilaueensis	∼2000 to ∼3000c	66.5	72.8
		A vs B
A. thaliana		42.4
M. polymorpha		42.3
C. merolae		42.3
G. kilaueensis		43.3

^aThe divergence time for each pair of land plant species was obtained from fossils reviewed by Clarke et al. [21] and are taken as the average value of the proposed hard minimum and soft maximum fossil dates.

^bThe younger date was taken from the molecular clock analysis presented in Ref. [22] for the divergence of C. merolae's clade, the oldest date from Ref. [24].

^cThe younger date was taken from ref. [3] and the oldest represent early geochemical evidence for oxygen in the rock record as reviewed recently [6, 7].