2011/08/02 by Laura Wegener Parfrey, Daniel J. G. Lahr, Andrew H. Knoll +1 · 7 citations
Biochemistry, Genetics and Molecular Biology · Earth and Planetary Sciences · #Ancestor #Biology #Clade #Diversification (marketing strategy) #Ecology #Evolutionary biology #Extant taxon #Gene #Genetics #Geography #Geology and Paleoclimatology Research #Molecular clock #Most recent common ancestor #Paleontology and Stratigraphy of Fossils #Phylogenetics #Protist diversity and phylogeny #Taxon
paper · doi:10.1073/pnas.1110633108
openalex publication_date 2011/08/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Although macroscopic plants, animals, and fungi are the most familiar eukaryotes, the bulk of eukaryotic diversity is microbial. Elucidating the timing of diversification among the more than 70 lineages is key to understanding the evolution of eukaryotes. Here, we use taxon-rich multigene data combined with diverse fossils and a relaxed molecular clock framework to estimate the timing of the last common ancestor of extant eukaryotes and the divergence of major clades. Overall, these analyses suggest that the last common ancestor lived between 1866 and 1679 Ma, consistent with the earliest microfossils interpreted with confidence as eukaryotic. During this interval, the Earth's surface differed markedly from today; for example, the oceans were incompletely ventilated, with ferruginous and, after about 1800 Ma, sulfidic water masses commonly lying beneath moderately oxygenated surface waters. Our time estimates also indicate that the major clades of eukaryotes diverged before 1000 Ma, with most or all probably diverging before 1200 Ma. Fossils, however, suggest that diversity within major extant clades expanded later, beginning about 800 Ma, when the oceans began their transition to a more modern chemical state. In combination, paleontological and molecular approaches indicate that long stems preceded diversification in the major eukaryotic lineages.