  Early-type dwarfs are the most common galaxy in the local universe, yet their
origin and evolution remain a mystery. Various cosmological scenarios predict
that dwarf-like galaxies in dense areas are the first to form and hence should
be the oldest stellar systems in clusters. By using radial velocities of
early-type dwarfs in the Virgo cluster we demonstrate that these galaxies are
not an old cluster population but have signatures of production from the infall
of field galaxies. Evidence of this includes the combined large dispersions and
sub-structure in spatial and kinematic distributions for Virgo early-type
dwarfs, and a velocity dispersion ratio with giant ellipticals expected for
virialized and accreted populations. We also argue that these galaxies cannot
originate from accreted field dwarfs, but must have physically evolved from a
precursor population, of different morphology, that fell into Virgo some time
in the past.
