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Ensatina distribution
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The photgraph above is of a hybrid between
the subspecies eschscholtzi and klauberi. Between these
two subspecies there are four hybrid zones discovered so far (2008), Those
localities are (1) the San Gorgonio Mountains, (2) San Jacinto Mountains,
(3) Palomar Mountains, and (4) the Cuyumaca Mountains, The first three show
a limited amount of hybridization; approximately 3%. (Brown, 1974) In the
Cuyumaca Mountains the two subspecies eschscholtzi and klauberi
are sympatric in a very narrow zone without any evidence of interbreeding.
Molecular evidence indicates these populations have not interbred for aproximately
two million years. The two subspecies indicate by every definition that
they have differentiated into two species. However, since the two are part
of this ring species and the seven subspecies show considerable gene introgression
among the various types, it does not seem appropriate to divide Ensatina
into two or more species. (Wake, 1997; Wake, 2006)