S. Wehbi

Order of amino acid recruitment into the genetic code resolved by Last Universal Common Ancestor's protein domains

The paper infers the order of amino acid recruitment into the genetic code by analyzing ancestral protein domain frequencies, finding smaller amino acids were added earlier and metal-binding/sulfur-containing amino acids earlier than previously thought.

The effectiveness of selection in a species affects the direction of amino acid frequency evolution

The paper examines how effective selection in species influences amino acid frequency evolution, finding that preferred amino acids are less costly to synthesize and use GC-rich codons, explaining 85% of variance in preferences.