Technical Comments

Technical Comment on “The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals”

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Science  09 Aug 2013:
Vol. 341, Issue 6146, pp. 613
DOI: 10.1126/science.1238025


  • Fig. 1 Polyphyletic ecomorphology groups.

    Polyphyletic ecomorphology groups from figure S2 (phenomic tree) of O’Leary et al. (1). Fossils and nonplacentals were pruned to highlight relationships among living placentals. Numbers next to groups indicate the number of “apomorphies” with Deltran optimization (13). [Paintings by Carl Buell]

  • Fig. 2 Substitution rates.

    Substitution rates (substitutions per nucleotide per million years) for 26 nuclear genes based on O’Leary et al.’s (1) hypothesis that ~10 interordinal speciation events occurred within 200,000 years. The rate for the 200,000-year interval (red bar) was calculated for the internal branches that lead from the placental common ancestor to the common ancestor of Macroscelidea and Afrosoricida, assuming ages of 64.95 and 64.75 million years, respectively, for these nodes (1). Other rates (blue bars) were calculated based on ages in table 1 and table S2 of O’Leary et al. (1). Molecular branch lengths are from Meredith et al.’s (2) DNA tree (TreeBase S11872). “Stem placental” is the branch leading from the most recent common ancestor of Theria to that of Placentalia. [Paintings by Carl Buell]

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