They examined genome sequences in around 29 mammals and compared gene regulation in liver cells from 20 key species and found out the reason behind the divergence of mammals instead of having same genes. They explained ways to turn changes in the genome into differences between species which included change of protein sequence, or by changing the way promoters or enhancers control that protein's expression.
The research team explained that even both the changes can occur at the same time when amino acid sequences evolve very quickly. Researcher Paul Flicek said that their research focuses on evolution re-purposes things that exist in all species, to make each species unique, and by looking at gene promoters and enhancers in many different mammals, their study demonstrated that species-specific enhancers come from ancient DNA. Researcher Duncan Odom explained that with their study findings they can now answer questions about the functional genetics of many under-explored, and this research has also given new insights into mammalian evolution.