Like Stefan I am no geneticist but I would remark that he seems to have been
seduced by the theory of the French naturalist J.B.P.A. de Monet de Lamark
that species have developed by the efforts of organisms to adapt themselves to
new conditions.  This was exploded by Charles Darwin over a century ago.
Where nutrition may have an effect upon genes is when it influences
reproductive success.  If better or worse fed bees produce more or less queens
and drones this will affect the relative quentities of their genes in the
pool, but will not create new genes or destroy old ones unless the creatures
do not reproduce at all.
Whether your grandfather lived on bread and water or caviare and chips you may
inherit his red hair or his bad temper but you will not inherit his wooden leg
unless he leaves it to you in his will.
Chris Slade