Changes in these networks are thus coupled to the evolution of new functions and functional relationships in the organism.
Development of new functional genes is central to the evolution of species-specific traits [ 1].
A common theme in the evolution of new functions consists of gene duplication followed by functional divergence.
After gene duplication, two duplicates can undergo substantial functional divergence, and it plays a major role in the evolution of new functions [40].
Functional divergence analysis among UCP family members indicated that substantial altered functional constraints have occurred on all UCP paralogues after gene duplication, which may have led to the evolution of new functions.
One of the legacies of our interest in progress is that we concentrate overwhelmingly on the appearance and spread of new functional traits when providing students with examples of evolution.
This may possibly indicate stronger selection pressures acting on NSPs than on the derived ESPs and TFPs and reduced functional constraints associated with the evolution of new biochemical functions.
But if some of those events are permissive, as our results suggest they are likely to be, then the potential of evolution to generate new functional complexes by the combined action of mutation, drift and selection is greater than it may appear if the molecules are viewed only in isolation.
