A simplified model representing genetic and ecological “speciation” within a group of closely
related prokaryotes (perhaps designated as species in a bacterial genus). “Genetic species A”
comprises organisms whose genomes are similar enough in sequence that recombination
(small arrows) can occur frequently for all genes, albeit at varying rates. “Genetic species B” is
defined similarly, but B genomes are sufficiently different from A genomes in sequence that
recombination between them is infrequent.
Camilla L. Nesbø et al. Genetics 2006;172:759-769
Copyright © 2006 by the Genetics Society of America