The galaxy ancestor problem
  HST finds galaxies whose Tolman dimming should exceed 10 mag. Could evolution
alone explain these as our ancestor galaxies? Or could they be representatives
of quite a different dynasty whose descendants are no longer prominent today?
We explore this latter hypothesis and argue that Surface Brightness Selection
Effects naturally bring into focus quite different dynasties from different
redshifts. Thus the HST z=7 galaxies could be examples of galaxies whose
descendants are both too small and too choked with dust to be recognizable in
our neighborhood easily today. Conversely the ancestors of the Milky Way and
its obvious neighbors will have completely sunk below the sky at z>1.2 although
their diffuse light could account for the missing Reionization flux. This
Succeeding Prominent Dynasties Hypothesis (SPDH) fits the existing observations
both naturally and well,including the bizarre distributions of galaxy surface
brightnesses found in deep fields, the angular size ~ inverse (1+z)
law,'Downsizing' which turns out to be an 'illusion' in the sense that it does
not imply evolution, 'Infant Mortality', i.e. the discrepancy between stars
born and stars seen, and finally the recently discovered and unexpected excess
of QSOAL DLAs at high redshift. If the SPDH is true then a large proportion of
galaxies remain sunk from sight, probably at all redshifts. We show that
fishing them out of the sky by their optical emissions alone will be
practically impossible, even when they are nearby. More ingenious methods will
be needed to detect them. It follows that disentangling galaxy evolution
through studying ever higher redshift galaxies may be a forlorn hope because
one will be comparing young apples with old oranges, not descendants with their
own ancestors.
