OF PEAS AND PUPS
PART X
INBREEDING
INTRODUCTION
THE PREPARATION OF THIS
SERIES has been enjoyable effort. Many letters, phone calls and personal
conversations have pointed up however, that I am getting through to but half of
my readers. I am not making my explanations clearly understandable to all. For
this I wish to apologize, and to say that I will proceed at a slower pace from
here to the conclusion....
INBREEDING HAS BEEN
CALLED a double-edged sword and I can think of no better description. It can
bring unimagined progress...it can bring disaster. For this reason I will make
every effort to hit the subject from many different angles and thus reducing
the possibilities of error or misunderstanding. You have an obligation to your favorite breed too. You must make some effort to understand
the action before jumping off, for often a LITTLE KNOWLEDGE IS MORE DANGEROUS
than none at all....Some, expect to be able to digest a discussion of genetics
with as much ease as reading a novel. For me, at least, this would be
impossible. Genetics is a subject one must study, not just read. As I have said
elsewhere...Outbreeding Without Selection will bring
no progress, but Inbreeding Without The Most Rigid Selection will Bring
Disaster!...And a breed which is growing in popularity as the Shorthair is, is
particularly susceptible to this hazard. I can assure you that if you will put
five minutes study for every hour I have devoted to writing, you will find your
time well spent...the knowledge helpful and the breed well served.
REVIEW
THIS SERIES WILL HAVE
BEEN MORE THAN two years in the writing and the printing. It has, of necessity,
appeared at rather infrequent intervals. (Your author is kind and your editor
admits to procrastinating a bit). For these reasons,
before proceeding, we shall very briefly review, for those who have come in
late, some of the elemental facts.
GENETICS IS THAT
DIVISION of biology concerned with heredity. The genes, from which the name
arises, cannot be seen, they are molecules in the nuclei of all cells (plant
& animal). It is the chemical action of these genes which determine the
reaction of the organism to its environment and these genes are passed from
parents to offspring in a regular and predictive manner based upon the
mathematics of probabilities.
MENDEL DISCOVERED THE
GENES while studying the heredity of simple garden peas. He called them determiners. He learned
that they were paired and that each pair controlled a particular characteristic
of the pea. Whether the pea had Round or Wrinkled Seeds depended upon one pair
of Determiners. Whether the stems were Long or Short,
depended upon another pair of determiners, and so on...He found that when he
mated pure smooth seeded peas with pure wrinkle-seeded peas, he always got
smooth seeds, regardless of which parent was smooth or wrinkled. The
"children" always looked like the smooth parent...the same PHENOTYPE
(appearance_. They did not have the same GENOTYPE (genetic make up) because
when the hybrid smooth offspring were bred together, sometimes wrinkled
grandchildren appeared. He called the wrinkle-seeded gene which lay dormant,
the RECESSIVE DETERMINER and designated it as "r" and the smooth
seeded gene which showed through, the DOMINANT DETERMINER, "R". Thus,
when R & r are mated, R always shows.....In order for r to show, it must be
paired, rr. This is basic.
IN PART II, we compared
the genetics of each chromosome (of which the dog has 78 chromosomes) with a
double strand necklace...two strings of black and white beads laying side by
side, one coming from the sire and the other from the dam. The figure is
reproduced here...
THE ABOVE VERY SHORT
PIECE OF the Gene String of one chromosome is present in every single cell of
the entire body of the dog. the Black Beads are the Dominants...the White
Beads are the Recessives...
GENERALLY, ALTHOUGH NOT
ALWAYS, the Dominants are favorable, the Recessives
detrimental...The only defect which will show it self here is at d'd1, Paired Recessives...All of the
other Recessives (at a, b , c & e) are covered up
by their Dominant partners (allemorphs). The defects are there but
they are hidden.
WE WILL ASSUME THAT THE
ABOVE illustrates the partial gene string o fa male
dog. In the formation of his Germ of Sex Cells, these double strands become
separated; divided right down the middle with one strand going into One Sperm
while the other stand goes into another sperm...Thus half of his millions of
sperm have four-defective-genes, which in Figure r, came from his sire and the
other half have three-defective-genes from his dam. Because of CROSSING OVER
(Part IV) it would be highly unlikely that a son would pass on to his
offspring, the complete-gene-string in the same alignment in which he received
it from his sire or dam.
A SIMILAR PROCESS TAKES
place in the dam and one-half her eggs contain one strand, while the other half contain the other strand. As the eggs are formed, they
each contain but a single strand of genes, rather than the pair. Thus, the
sperm and the egg are but half-cells, so far as genetic make-up is concerned.
When they unite at fertilization, the ZYGOTE
(fertilized egg), contains two strands and we arrive back where
we started, a new generation has sprung to life, made up of a Sire-Strand and a
Dam-Strand. It doesn't take much imagination to see the great variety which can
result from this shuffling process when we realize that we are dealing with 20,000 or more genes in 78 Chromosomes.
WHEN A PAIR OF LIKE GENES
MEET, whether dominant, RR, or recessive, rr,
we say the Zygote is Homozygotic
for that characteristic. When the Allemorphs are
different, Rr, the term Heterozygotic
is used. We can see from this that if one parent is Homozygous Dominant for a
certain characteristic, he or she is prepotent for
that characteristic because regardless of the mate, all the offspring will show
that trait....But a parent which is Homozygous Recessive, although he shows the
trait, cannot be prepotent for it because the Recessives-must-be-paired-to-show
and he cannot possible pass both recessives to an offspring because they will
not be in the same sperm.
LETS FOLLOW THIS
through with a single pair of genes in a single chromosome from a dog and
bitch....
THE CHARACTERISTICS WE
SEEK in our dogs are, in most instances, not controlled by a single gene pair
as are the round-wrinkled characteristics of the pea there may be hundreds of
gene pairs involved in the expression of nose or run, yet the same rules apply
and the difference lies in a matter of degree and complexity....So, what does
all this Dominant/Recessive bit mean to the Shorthair breeder?....It means that
if a hundred genes control a certain characteristic it is going to be 100 times
harder to read but because you or I lack the ability to read it, makes it no
less a fact. The Dominants are going to show in every generation, and we should
be able to see them in most pups, although there will be considerable
variation. The more obvious these multi-gene traits appear, the more dominants
for that trait the pup is likely to possess and the more likely he will be to
be able to pass it along.....The higher the percentage of his pups which show that
trait, the greater his Homozygous
Dominance, his prepotency....Dominant
defective traits are easily eliminated because they show. The Recessive-Defects
are difficult to eliminate because they must be PAIRED to show, they must be
Homozygous...They can arise from parents neither of which show the defect,
Recessives rarely show in successive generations; they skip around and may hide
form many generations before jumping up to bite us. They must come from both
sides of the house before we are aware of them....As we shall see later, nature
has an effective shuffling-machine which can assist us by bringing there pairs
to the surface where we can see them and get rid of them...While it is pairing
these white-defective beads, it will also pair the black-ones to give us prepotency, as a bonus!...So much for the review. Further
data is available in the earlier parts of this series and in the text cited.
INBREEDING
DEFINED
INBREEDING IS A PLAN
BASED upon the relationship of the mates...Genetic relationship within a breed
is based upon the homozygotic genes in common (Part IX), not
necessarily just the genes in common....Man and monkey share some 95% of their
genes in common, but they do not share nearly as many Homozygotic
(like) genes in common. The more
LIKE genes two dogs possess, the more closely related they
are....Since we cannot know with certainty these genes, we must use terms which
have the greatest likelihood of indicating that genetic relationship; always
being mindful that these relationships and therefore the breeding plans based
upon them, are but probabilities, not certainties.
INBREEDING is the mating of animals more
closely related genetically than the average for the breed. It is a plan which
joins more like genes at fertilization, than a random mating....Since we do not
know the average for the breed, for convenience, we set that average here
between the fifth and sixth generation. This gives us a starting point....We
can say, that if the same name appears on both sides (sire's & dam's) of
the usual five-generation German pedigree, we are inbreeding (some would say
line-breeding). I have heard theat statement roundly
criticized. The truth of the matter is, of course, that such is not a statement
of fact but rather a statement of probability....Although it may not be true in
specific litters....The closer to the pups the names appear,
the closer the inbreeding is likely to be. This is because the more generations
the genes must travel, the more opportunity they have to play
"hopscotch".
THE "COMMITTEE ON
INVESTIGATIONS OF THE American Society of Animal Production" defines
inbreeding a bit differently...They say, that in order to be classed as inbred strain, the individuals must have an
average co-efficient of inbreeding of at least 37.5%. - That's the
equivalent of two generations of brother-sister-matings
or two of parent-offspring-matings - By that
definition, how many inbred
Shorthairs do you know? I only know of a litter or two, and you
know the dogs in those litters too, because, you cannot pick up a GSP News of
the last three years in which at least one of these dogs
names does not appear, because they are outstanding dogs, always right on top.
THE EARLY GREEKS were
highly intelligent and civilized. Their interest in government and the arts, their
encouragement of learning and appreciation of knowledge was matched only by
their devotion to the healthy body and admiration of strength and physical
dexterity. The Greeks could hardly be called a degenerate people. Yet, the
Greeks sanctioned marriage between half-brother and sister. There are many
today who consider such abhorrent, even among dogs, and predict ruination for
any breed in which such occurs. Of course such is sheer nonsense. We need not
bind our dogs by human codes and degeneracy will only come, when and if, we
lower the bars of RIGID
selection.
ACTUALLY MANY FINE
SHORTHAIRS have come from the mating of half-brothers and sisters. When I say
"many", I mean "many" for the few times it has been
attempted. I have not searched the records but several come to mind of hand.
One of the finest bitches I know, was the result of
such a union. She was for many years the only International Dual Champion in
the breed. The last time I saw her put down, she out-ran and out-hunted
stake-mates 6 and 7 years her junior and, in fact, actually became lost. I am
referring to Am. & Can. Dual Ch.Gretchen v Greif, owned by the
Senior Parks of
ONE OF THE MOST
EXCEPTIONAL litters of the last few years was also a half-brother-sister
mating. At this writing, it has produced out of a litter of six, Dual Ch.Albrecht's
Baron Cid, Dual ChlAlbrecht's Baroness Cora, Fc Baron Cy (who may well have his dual by the
time this reaches print) and Ch.Albrecht's Baroness Cara. The two other pups of the litter Cito and Cato, were never campaigned
although they are sound and rugged, and efficient hunting companions for their
owners. The litter was bred by the Albrecht's
of
Dixon's Starlite was the dam of both National
FC Dixon's Sheila and National FC Dixon's Skid-do. The mating of
this half-brother-sister pair produced FC
Dixon's Shiloh Sky. Who do you suppose bred those dogs? Russell V. Dixon
of
FULL BROTHER-SISTER
MATING is as close as we can breed animals. Winge, referred to
earlier, says that his search for results from full sib-matings
(brother/sister) have given very contradictory reports, which is understandable
since inbreeding is a double-edged sword, it
cuts both ways. On the other hand, Whitney ("How to Breed Dogs" Orange-Judd NY '48),
who probably bred more dogs than any other scientist, reports he found no more
abnormalities in his full-sib matings in the
first-generation-than-in-his-random-matings...So, you
pays your money and you takes your choice...I am aware of but one recent full-sib mating in Shorthairs.
The sire and dam were littermates by
THESE EXAMPLES ARE NOT cited, to
encourage brother-sister or half-brother-sister matings
among the Shorthair fancy. ITS SOLE PURPOSE is wipe
off the blinders! To expose the old wives tales, which keep so may rooted to
fables, and further, to disprove the oft-heard phrase, "Inbreeding has
never done anything for the Shorthair"....Consideration of the examples
will indicate to any thinking-persons, the success of inbreeding Where The Parents are Outstanding.
Average specimens ARE NEVER INBRED.
Individual selection...the
art of breeding...is the only key to success and it does not
come simply.
IT IS INDIVIDUAL
SELECTION which tells us if the pedigree and the dog agree. There can be a
great deal of difference between pedigree-inbreeding and
genetic-inbreeding....This difference is the exception and not the rule.
Remember the dog wags the pedigree and the reverse is not true.
OUTBREEDING
ON PAPER...Pure and simple. Inbreeding in fact - just as pure, just as simple....Early in this
series, I said that in discussing theory, there would be ample space for
differences of opinion. This is not one of those places. GREIF was inbred...there's
no theory to it - it is fact! Some might say that GREIF'S greatness came
through hybrid vigor or HETEROECIOUS (Part V). Such could have
provided his Phenotype-greatness,
but only the likeness of genes could have provided his prepotence...when
like-genes meet, inbreeding takes place....According to the records,
he was the most genetically-inbred Shorthair in the
PERMIT ME A SLIGHT
DIGRESSION. All are seeking the perfect dog. All of us are aware of its
impossibility. Since perfection is unattainable, we are all forced to
compromise with our ideal. If only perfect dogs were bred there would be no
breeding. We must balance the severity of the faults in a given dog to his
probable good to the breed and the closer we inbreed, the higher our standards
must be...the more critical our selection. But, we cannot knock out a dog, for
example merely because she has a tail set a bit lower than we would wish, if
she has many other virtues which would be helpful to the breed...To me, a low
tail carriage is a greater fault (how the tail is carried) than low tail set
(angle it grows from body & extends). If we cannot have both, I'll take high
carriage over high set. Some will say that a low set indicates and anatomic defect, and I agree. But, low-carriage often means a
psychological defect...not always severe, but a defect not the less. A high
tail carriage indicates sound mental structure to me...not necessarily
"intelligence" but certainly personality and in such an instance,
I'll take the personality over the anatomy. This may be a little thing but I
know some who would no more breed a dog with a little low set than they would
fly and yet mate faults I consider far more damaging.
I AM NOT RECOMMENDING
the breeding of major faults, but where do you draw the line? I do recommend
that we be practical; that an otherwise promising sire or dam not be neglected
because of some minor fault....Now, would you breed a
dog wich was anatomically unable to make a
"tie"? - How serious is this? - Is it hereditary? - GREIF brought
this question to mind because many thought him of questionable virility. They
were unaware that he as anatomically unable to make a tie. Fortunately, he was
bred and I only wish he had left more offspring...the breed would be the
beneficiary. Don't imagine that your dog is perfect. HE IS NOT...and if you
cannot see his faults, get someone else to fault him for you but don't become
angered by their comments.
LINBREEDING
DEFINED
NOW THAT WE HAVE SOME
IDEA of what inbreeding is, we shall talk about the division of inbreeding
called linebreeding....After both terms have been defined,
we shall talk about their results and the genetic action involved. LINEBREEDING
is an inbreeding plan directed toward some particularly outstanding specimen of
the breed....We try to increase the genetic-relationship
between this outstanding individual and our pups...To accomplish this, we
wither breed directly to this dog, or if that is impossible, we try to mate
animals closely related to him (or her) but related to each other through no
other line...If our mates were related on both sides of the house, we would be
inbreeding and would stand much less of a chance of effectively increasing the
genetic-relationship between our ideal and our pups...In other words, the
mating of half sibs (same sire) would make the pups tend to resemble their
grandfather, be more closely related to their grandfather than the mating of
full sibs....In the latter instance, the genetic force of the grand-dam would
be equal to that of the grand-sire. The half sib mating would be linebreeding, whereas, the full sib mating would be
inbreeding....
IF WE ARE ANXIOUS TO
LINEBREED to a certain outstanding stud dog, we will do better to start with a
bitch which is in some way related to him...Our second best odds would come
from the bitch which is completely outbred. We could
expect the least chances of success to accompany a breeding with a bitch
inbred-in-another-strain....When I speak of "success" I am assuming
that we are linebreeding to this individual because
we like his type, his appearance and his actions, and that is what we are
after.
LINEBREEDING SUCCEEDS
OR FAILS to the same degree and for the same reasons as inbreeding, which, in
fact, it is...So that all which will be said about inbreeding APPLIES EQUALLY
to linebreeding, when the same degree of intensity is
present...It is true that if both plans are carried to their extreme limits, linebreeding cannot become as intense...but, Shorthair
breeding as it is today, makes this fact of only theoretical interest....Linebreeding reaches a maximum at 50%, while inbreed can reach
a theoretical 100%, but so far as I know, there are no Shorthairs at the 50%
mark, inbred or linebred....50% would be reached with
approximately four-generations of parent to offspring matings
or three-generations of full-sib matings.
ACTUALLY, THE MOST
INBRED SHORTHAIR litters are also the most linebred...This
may sound like double-talk but we can inbreed without linebreeding...but,
we CANNOT linebreed without inbreeding...From this
litter, the most inbred/linebred bitch in the USA is
also the "Top Field Dog of the Year" according to BOTH Parent Clubs
and this is the second year she has been so rewarded by the NGSPA. FC Moesgaard's
Lucky II is the girl (Fx.438)...Coincidence?...Her
sire, her grandsire and her great-grandsire were one and the same, the great
Danish import, international FC Moesgaard's Ib.
Coincidence?...Who said inbreeding never did anything for the Shorthair? Let's
face facts...for the little inbreeding practiced in the Shorthair generally,
the percentage of wins (field wins) by closely bred (this is a relative term)
dogs so far outweighs their percentage int he
Shorthair population as to leave little comparison possible.
Part 1 | Part 2 | Part 3 | Part 4 | Part 5 | Part 6 | Part 7 | Part 8 | Part 9 | Part 10 | Part 11 | Part 12 | Part 13 | Part 14 | Corrections to Part 12 & 13
Copyright 2001. Dr. James G. McCue, Jr. All rights
reserved. Postscript: And his legacy lives on in the German
Shorthaired Pointers of today. May they
always be healthy and bred with forethought and planning.
Return
Home