  A field theory is proposed where the regular fermionic matter and the dark
fermionic matter are different states of the same "primordial" fermion fields.
In regime of the fermion densities typical for normal particle physics, the
primordial fermions split into three families identified with regular fermions.
When fermion energy density becomes comparable with dark energy density, the
theory allows new type of states. The possibility of such Cosmo-Low Energy
Physics (CLEP) states is demonstrated by means of solutions of the field theory
equations describing FRW universe filled by homogeneous scalar field and
uniformly distributed nonrelativistic neutrinos. Neutrinos in CLEP state are
drawn into cosmological expansion by means of dynamically changing their own
parameters. One of the features of the fermions in CLEP state is that in the
late time universe their masses increase as a^{3/2} (a=a(t) is the scale
factor). The energy density of the cold dark matter consisting of neutrinos in
CLEP state scales as a sort of dark energy; this cold dark matter possesses
negative pressure and for the late time universe its equation of state
approaches that of the cosmological constant. The total energy density of such
universe is less than it would be in the universe free of fermionic matter at
all. The (quintessence) scalar field is coupled to dark matter but its coupling
to regular fermionic matter appears to be extremely strongly suppressed.
