  Gravlenses are efficiently explored for detecting the most distant galaxies
(up to z=10 redshifts). As an example of the role played by gravlenses we refer
to the observation of the galaxy merger at z=3 (Borys, et al; Berciano Alba, et
al). We derived solutions for the Smoluchowski kinetic equation for the mass
function of galaxies, which describes mergers in differential approximation
(minor mergers).
  It is shown that the evolution of the slope of luminosity function observed
in the Ultra Deep Hubble Field (Bouwence et al) can be described as a result of
explosive evolution driven by galaxy mergers.
