Our work sheds light on the fundamental problem of metabolic diversification and the emergence of shared catabolic pathways.
Similarly, carotenoid compounds with greater enzymatic connectivity were the evolutionary "hotspots" of metabolic diversification in a sample of 330 bird species [ 29].
The construction of robust and well resolved phylogenetic trees is important for our understanding of many, if not all biological processes, including speciation and origin of higher taxa, genome evolution, metabolic diversification, multicellularity, origin of life styles, pathogenicity and so on.
By keeping track of pathway activation, cell densities, metabolic fluxes and nutrient concentrations, we gained detailed insight into the processes driving the successional dynamics of metabolic diversification.
These studies nicely illustrate how metabolic diversification occurs in the face of resource competition.
We found that diversification in expressed carotenoids was the greatest in recently diverged species (<20 my in lower panel of Fig. 1c) and was produced by metabolic diversification (middle panel, Fig. 1b) and not by shifts in dietary (external) starting points (upper panel, Fig. 1c).
These data further support the view that differential lineage expansions of the BAHD family may be linked to taxon-specific metabolic diversification.
Such potential connectivity gives us an opportunity to empirically evaluate the relative contribution of ecological (e.g., switching among external dietary compounds) and biochemical (e.g., internal metabolic diversification) aspects to evolutionary diversification in avian colors.
We test empirical predictions of this trade-off in extant bird species, explore its likely evolutionary trajectories, and use it to calibrate potential for metabolic diversification across avian taxa that utilize diverse dietary carotenoids.
It is generally accepted that horizontal gene transfer (HGT) is an important process in bacterial genome evolution, which provides both novel metabolic capabilities, and catalyzing the diversification of bacterial lineages [ 1, 2].
