Genes and speciation

It is only in the past five years that studies of speciation have truly entered the molecular era. Recent molecular analyses of a handful of genes that are involved in maintaining reproductive isolation between species ( speciation genes) have provided some striking insights. In particular, it seems that despite being strongly influenced by positive selection, speciation genes are often non-essential, having functions that are only loosely coupled to reproductive isolation. Molecular studies might also resolve the long-running debate on the relative importance of allopatric and parapatric modes of speciation.