Ancient protein domains remain shaped by amino acid availability during early life, while young animal proteins are shaped by a need for high intrinsic structural disorder.

Analysisof P-loop NTPases and Rossmans, the most ancient and diverse enzyme lineages, suggests their divergence from one ancestral polypeptide.

The genome of Thermovibrio ammonificans encodes ancestral pathways (e.g., hydrogen oxidation) and more recently acquired ones (e.g., nitrate reduction) and a hybrid pathway for CO₂ fixation.

The convergent evolution of unusually strict substrate specificity in apicomplexan LDHs arose by classic neofunctionalization of a duplicated MDH gene via few mutations of large effect.

Comparative genomics and three-dimensional protein modelling identify homologs of insect chemosensory receptors in unicellular eukaryotes and plants.

The animal phylogeny of glutamate receptors indicates that vertebrate types do not account for all receptor classes originated during evolution, neither are they the pinnacle of a linear evolutive process.

A comparative study of modern proteins identifies 40 fragments that may represent the observable remnants of a primordial RNA-peptide world.

Sponges and ctenophores lack hypoxia-inducible factors, suggesting that the metazoan last common ancestor could have lived aerobically under severe hypoxia and did not need to regulate its transcription in response to oxygen availability.

Despite billions of years of divergence, a majority of prokaryotic genes can functionally replace their essential eukaryotic counterparts, revealing broad preservation of ancestral functions and identifying heme biosynthesis as a near-universally swappable pathway.

The first genomic view of beetle luciferase evolution indicates evolutionary independence of luciferase between fireflies and click-beetles, and provide valuable datasets which will accelerate the discovery of new biotechnological tools.