Full Idea
Contradicting one of the main points of essentialism, there is no reason in principle why a species should not survive the demise of its current genetic mechanisms (some other species coherence gradually taking over).
Gist of Idea
A species might have its essential genetic mechanism replaced by a new one
Source
John Dupré (The Disorder of Things [1993], 2)
Book Reference
Dupré,John: 'The Disorder of Things' [Harvard 1995], p.55
A Reaction
I would say that this meant that the species had a new essence, because I don't take what is essential to be the same as what is necessary. The new genetics would replace the old as the basic explanation of the species.