A long-term evolution experiment with Escherichia coli shows that the appearance and optimization of a new trait can require both co-opting existing cellular pathways for new roles and reversing a history of previous adaptation.
Experimentally reconstructing the evolution of the molecular complex that animals use to orient the mitotic spindle establishes a simple genetic and physical mechanism for the emergence of a function essential for multicellularity.
Combined antigenic and genetic analysis shows that different strains of the human influenza virus display dramatically different rates of antigenic drift, and that these differences have a significant impact on the number of new infections in each flu season.
Experimental mapping of the joint sequence space of an ancient transcription factor (TF) and its DNA binding sites reveals that epistasis across the molecular interface permitted the evolution of a new and specific TF-DNA complex.
The evolution of the light-sensitive visual pigment rhodopsin involved functional tradeoffs that may have sacrificed rod photosensitivity for active-state protein stability to mitigate phototoxicity in tetrapods, but not in fishes.
Despite their extreme morphologies, snakes display a global regulatory strategy of their Hox genes similar to that implemented by mammals with, however, important modifications in enhancer specificity.