Epigenetics and Evolution

The mechanism of evolution has not been discovered.  No consistent theory exists. Random mutations adapting to changing environments was the first suggestion.  When subatomic radiation was discovered, that became a proposal.  Now, epigenetics may indicate another, more powerful, model.  

Darwinian evolution does not explain the lack of intermediate forms. Scientists have bombarded fruit flies and mice with every radiation known and produced no new species.

Jason Head, assistant professor of Earth and Atmospheric Sciences,
at the University of Nebraska Lincoln
holds a fossil and fossil cast from the jawbone of
Barbaturex morrisoni, a large ((2 meters; 30 kgs) lizard
that coexisted with mammals in southeast Asia
40 million years ago. (Press release here.)

Epigenetics is the study of how environmental factors affect the expressions of genes.  We know that we share something like 90% of our DNA with yeasts - and yet we are very different from them. We know that strawberries have not a double helix, but a quadruple helix - yet they are not "superior" to us double helix lifeforms.  
  

A series of prehistoric creature illustrations demonstrates
the evolution of mammals through the ages.
More fact than fiction, these wild characters followed transitional Jurassic period animals
that sported mammalian skull traits and reptilian teeth.
A more familiar design, humans, mark the present.
- National Geographic, "The Rise of Mammals"

Random mutations adapting to changing environments is a (partial) explanation. Radiation seems to create such mutations, also. Epigenetics offers another aspect of understanding. It seems that the mechanisms of process are inherent in all life, but the millions of components are active or inactive according to causes we may now be coming to understand -- given that in 50 or 100 years some other engine will be discovered. 

Also on Necessary Facts
Epigenetics 
The Origin of What?
Biohackers 
Bob Swanson and Genentech