Transition Studies in Flowering Plants 
by Rolf Baumberger

What is the core benefit of these studies?

We describe here morphologically rapidly changing ecotypes in the genus Diplacus (Mimulus aurantiacus) and also similar phenomena in other genera.

By "rapidly changing" is meant within ten to 15 years. 

Is the plasticity of the flowers only morphologically or also genetically fixed? It would be best if you understood this morphologically alter of the shape in the real sense. Any one plant in a transition belt may change the floral and non-floral properties on an individual base. All plants together within this belt show generally the same trend when time goes by.

Is it also genetically expressed? Yes, that is correct.

How do we imagine that?  We can check the main transcription factors that regulate floral and pigment properties of the flowers. They alter their regulating activities and their genetic imprint slightly according to environmental needs. It is an active, time - and energy-consuming process that brings about adaptation for the whole plant populations in question.

Evolution in this species is mainly related to gene regulation, which alters in the context of environmental demand and is also hereditary.  With this speed, populations of Diplacus aurantiacus are currently altering their floral traits in the so-called «hybridization zone».

How flowers on long-lived plants may morphologically change over 15 years [model presentation].


We postulate a pushmi-pullyu internal molecular evolutionary mechanism that leads to altered life forms when a threshold is reached --> PP-Hypothesis.


One should extend this principle of "pushmi-pullyu" to the animal world as well e.g. Bombina bombina/variegata ...

Molecular Phylogenetics and Evolution 38 (2006) 705–718