Table 7 : The evolutionary history of stemness and cell differentiation.

Age (MYA) Eon Main oxygenic event Oxygenation Fossil records LECA’s life cycle stages

3850 Archean -- Ocean-atmosphere system O2 free;
Oxygen traces by water photolysis
(oases); H2, CO, H2S, Fe bound O2
-- SH

2450 Paleoproterozoic GOE Reduced substances decreased (H2, CO,
H2S, Fe); Oxygen accumulates in surface waters; Deep ocean oxygen free
stem-group Protists MH

1750 Mesoproterozoic OMZ Oxygen fluctuations in the Cellular differentiation: anoxic deep ocean; OMZ
in shallow oceans; Redox heterogeneity
in sub-surface waters (static stage)
Cellular differentiation: 3
different cell types; 2
developmental programs
(Knoll et al 2006,
Butterfield 2004, 2005)

1000 Neoproterozoic -- Oxygenated shallow oceans;
Anoxic deep ocean (Ice age)
Eukaryotic divergence MO
800 -- NEO -- -- --
750 -- -- -- -- stem cell protolineage

540 Cambrian -- -- Cambrian explosion --

GOE: Great oxygenation event; OMZ: Oxygen minimum zone; NOE: Neoproterozoic oxygenation event; SH: Strict hypoxic stage;
MH: Moderate hypoxic stage; MO: More oxygenic stage

Vladimir F Niculescu Stem Cell Biology and Research  2015 2:2DOI : 10.7243/2054-717X-2-2