by Rolf Baumberger 


There are two possible explanations for this phenomenon of gradual transition from one Diplacus plant variety to another:

◊  Merger hypothesis

Two varieties that were previously separated for many years meet a second time and form a hybridization zone at the contact sites, which persists for many years. see ->

◊ Splitting hypothesis

Because there is a great clinical dynamic in this zone, and the flowers of the individuals can change from one shape to the other and the new state is hereditary, we may conclude that:
A molecular mechanism is responsible for the transition, which goes beyond epigenetics. As a result, under the influence of an environmental change, two subspecies or species emerge that will eventually no longer spatially overlap. The whole process can be followed by monitoring and can also be elucidated molecularly. In the process, the two new forms increasingly stabilize.

See this study -->