Incomplete Lineage Sorting at the Species Level
The broad outlines suggests
the relationships of three biological species (sensu Mayr):
Species 2 & 3 are more closely related to each
other than either is to Species 1, though all are
descended from a pre-existing Species 123.
The Red and Blue lines are representative of coalescent
lineages that are, respectively, reciprocally
monophyletic and incompletely
sorted with respect to the three species.
Comparison of genes in Red lineages would correctly identify
the species' relationships. Comparison of genes in Blue
lineages would incorrectly suggest a closer relationship of Species
1 & 2.
Figure © 2013 by Sinauer; Text material © 2017 by Steven M. Carr