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An Ice Breakthrough!
We had an in-depth discussion on the Ice factor in the yahoo group pigeongenitics101,
and I asked Gene Hochlan the following question to sum it all up for me. Gene
is one of the top genetics experts alive today.
Q: Ice is not an actual gene but the result of selective breeding?
A: All of the evidence we have from various fanciers over the years
definitely points in that direction. I prefer using the term "directional
breeding" and Douglas McClary has pretty much proven that with his good
work in producing "powdered" which, in my opinion, is a form of
primitive Ice. The "powdered" Show Racing Homers are close to Ice
but are not quite there yet. Paul Gibson's summary statement;
"manipulated genetic drift" also pleases me. I believe our group
discussion (in pigeongenetics101) phased out the old belief that Ice is a
distinct mutated gene and that is why no one has ever gotten the expected
progeny testing results. Am not entirely sure if someone should get credit for
this breakthrough but I believe that we have an original achievement where our
pigeongenetics101 group site is concerned. You may do whatever suits you with
the above information. It is important and should be shared with the pigeon
More comments from Gene: This phenotype does not respond to
normal testing procedures. When Ice is mated to wild type the
result is an overall, half-tone copy and if you pair up the crosses they
will produce more of the same with a slight variation of blue shades.
Once in a great while a decent colored Ice is produced.
Fanciers have found it necessary, when introducing Ice into a different
breed, to back cross to Ice in order to make any real progress.
Paul Gibson referenced "manipulated genetic drift" when we
concluded our discussion on this subject. In nature all
"wild type" phenotypes are the result of genetic drift due to the
sum of all environmental conditions, hazards and mutations.
The end results that we see in wildlife have taken thousands and sometimes
millions of years. In confinement we can manipulate this process and
put it on "fast track". The Ice coloration that we
see in Damascenes and Ice Pigeons is very similar to a new, man made
"wild type". Had it not been for Douglas
McClary's work in producing "powdered" through directional
breeding, always selecting for the lightest blues, we would
still be groping in the dark concerning Ice. If I remember correctly
it took him 50 years to make his accomplishment and that is true dedication.
Most of us have a picture in mind as to what the original Rock Pigeon (Columba
livia) should look like but that image may be erroneous. The variation
of the blue ground color varies from very light to extremely
dark. The best illustration I have ever come across depicting the Rock
Pigeons from around the globe is in Derek Goodwin's book - Pigeons and
doves of the world. It is unfortunate that this color plate cannot be
purchased separately. The darkest blue Rock Pigeon comes from tropical
West Africa and the lightest one from the Dakla Oasis. All of these
birds are perfectly fertile when interbred.
Suppose we mate the two color extremes together. I doubt seriously that
one blue version would be dominant
to the other and our outcome would be an intermediate shade of blue.
This depicts my reasoning where the
Ice phenotype is concerned. Someone in the distant past did not have an
Ice blue pigeon appear in the nest
as a mutation but rather this phenotype was created incrementally; over many
years. If we mate Ice to "normal"
blue it will completely disappear in three to four generations.
In summary then the blue ground color of pigeons can be altered through
directional breeding without actually changing the basic gene or genes
responsible for it.
Q: So that means Ice is the phenotype of a domestic breed of
Blue Bar without any additional modifiers present?
A: According to my deductive reasoning that would be correct.
A man-made wild type