(1) More generally, there is a need to discriminate between the effects of chromosomal rearrangements and linked genic incompatibilities in both plants and animals.(2) Therefore, different grass lineages show lineage-specific patterns of local evolution in genic and intergenic sequences.(3) Reproductive isolation is often caused by the disruption of genic interactions that evolve in geographically separate populations.(4) The simplest case involving natural selection is genic selection in the absence of extinction and recolonization.(5) This, in turn, should help us identify selective forces that act within genes and thereby understand which genic features are of functional significance.
