In the 20th century, animals such as mules and ligers that had parents of different species were considered biological flukes, but genetic sequencing is beginning to unravel the critical role of hybridization in evolution.
From regulating each other’s gene expression to encoding different parts of the same proteins, the two genome types in every eukaryotic cell are far from independent.
Interactions between mitochondrial and nuclear genomes have further-reaching effects on physiological function, adaptation, and speciation than previously appreciated.
Tim Rogers, Alan J. McKane, and Axel G. Rossberg | Nov 1, 2013 | 4 min read
Biologists have struggled for centuries to properly define what constitutes a “species.” They may have been asking the wrong question—many smaller organisms might not form species at all.