Incest, or inbreeding is forbidden on moral and legal grounds in most human cultures but the prohibitions also
make sense on from a biological sense.
Inbreeding depression is the loss of viability or function resulting from inbreeding. The signs of inbreeding
depression most easily identified as reproductive failures. These reproductive failures may show themselves as
stillborn and deformed offspring, small litters, low sexual libido in the parent dogs, low sperm count in males while
females may fail to get pregnant, have unusually small litters, or exhibit poor mothering ability.
Inbreeding depression may also manifest itself as poor health, temperament problems, mental health disorders, and
reduced ability to learn new tasks.
Inbreeding depression can be manifested as a high frequency of immune-mediated diseases, significantly higher
incidence within a line or breed of one or more diseases than is seen in the species as a whole, or even things as
subtle as dogs that seem to catch every illness that comes along. In some cases, a very inbreed lines may go extinct.
"In general, the average poodle inbred less than 6% will outlive those
inbred over 25% (10 generation calculation) by about 3 years."
Dr. John B. Armstrong PhD
”…the breeding of purebred dogs is akin to [breeding laboratory mice]…
[most breeds] are becoming progressively more inbred. My observation is
that most are on the road to extinction, but most breeders do not even
realize they are part of an experiment.”
John B. Armstrong, PhD
In breeding.... why we will not do it...
Another Good Reason for not inbreeding: Low Genetic Variation:
Genetic variation is the raw material of evolution. Without genetic variation, a population cannot evolve in response to changing
environmental variables and, as a result, may face an increased risk of extinction. For example, if a population is exposed to a new disease,
selection will act on genes for resistance to the disease if they exist in the population. But if they do not exist—if the right genetic variation is
not present—the population will not evolve and could be wiped out by the disease.
As an endangered species dwindles, it loses genetic variation—and even if the species rebounds, its level of genetic variation will not.
Genetic variation will only slowly be restored through the accumulation of mutations over many generations. For this reason, an endangered
species with low genetic variation may risk extinction long after its population size has recovered. Evolutionary theory suggests that, for the
long-term survival of a species, we need to conserve not just individual members of a species, but also a species’ ability to evolve in the face
of changing environmental variables—which means conserving individuals and genetic variation.
When a species loses too many individuals, it becomes genetically more uniform and less adaptable to changing ecological conditions.
Now one may ask what this means to domesticated pets? Well if there was a deadly disease introduced and the population of dogs lacked
genetic variation there is a very good chance very few dogs would survive the epidemic. Genetic Variation is vital in ensuring our breeds
So what does this mean to the Standard Poodle and us here at Paris Poodles? As one of the breeds biggest fans and one of its breed
wardens we accept the responsibility of ensuring the breed has a future. We will simply not allow our breed to go extinct.
Why inbreeding Rarely occurs in Nature
Wild species of all kinds employ a number of behavioral strategies to avoid inbreeding. If Nature does something so consistently, you can
bet there is good reason. Among social animals, the young of one or both genders may disperse to form or join other groups. Dominant
breeding males may hold their position only a short time. Solitary animals tend to be territorial, at least in breeding season, with a male’s
territory overlapping that of several females. Their offspring must disperse and seek territory elsewhere, sometimes traveling long distances
to do so. But even in nature, conditions are occasionally such that an animal has no choice but to mate with a relative.
Islands that are well away from the nearest mainland gain species only rarely, when a very few individuals arrive through some accidental
circumstance. If they survive the initial inbreeding depression they adapt to their new environment, sometimes to the point of forming entirely
new species as can be seen with the finches and tortoises of the Galapagos Islands. But because island species have such a narrow
genetic foundation they are highly susceptible to anything that changes their environment. Native Hawaiian species have been severely
impacted and many driven extinct by their inability to adapt to the presence of species that accompanied early Polynesian migrants as well
as more recent introductions by American, European and Asian settlers.
The Standard Poodle is lucky to have begun with many founders. This means there should be many dogs to choose from to avoid
inbreeding. However, our breed, like most others, has experienced historic inbreeding stemming from the choices made by recent
generations of breeders who have used one sire more than others or frequently sought the output of a particular kennel.
Laboratory mice are often pointed to as proof that extreme inbreeding works. THIS IS INCORRECT!!
Lab mice are arguably the most inbred of domestic mammals; so much so that members of a strain are near clones of one another.
This extreme inbreeding is necessary so researchers will know exactly what to expect from that particular strain.
Strains are developed by breeding mice brother to sister for many generations, producing levels of inbreeding unheard of in dog
circles. But there is a price to be paid for this. In 20 generations, 80% of the lines descendant from the original pair will have gone
extinct due to lethal health problems or an inability to reproduce. Even those that make it through the genetic bottleneck are hardly
the mice their ancestors were. Take any pair of field mice put them in a laboratory cage and they survive very well, living longer than
they would in the wild. Take any pair of lab mice and put them in a field and their “wild” life expectancy is zero. They are suitable only
to the very controlled environment of a laboratory, where the “weather” never changes, food, water and housing are provided and
there are no predators.
The level of inbreeding is usually measured using a formula called Wright’s Coefficient of Inbreeding.
It calculates the probability that genes may have been inherited from both sides of an individual’s pedigree. It is far
too complex to do by hand over more than two or three generations, but some of the better pedigree software will
calculate coefficient of inbreeding (COI) for you. The usual 3-5 generation pedigree won't give sufficient information
for a useful calculation. The best indicator for calculating inbreeding COI is 10 generations. (Going back 10
generations represents 1024 ancestors)
Modern breeders should know the COI of each of their dogs and determine what the COI will be on planned litters.
Standard Poodles average around 18%. (This is roughly equivalent to all of them being half-brothers and sisters.
Some of the tops stud dogs in the Show World average over 25% or more!) This is unacceptable!!!
Any mammal whose COI is over 6 % is inbred.
Although inbreeding in dogs has had very little study from the scientific community;
This theory of inbreeding as been proven, in ALL OTHER SPECIES studied, to be a faulty and deadly.
|Effects of Inbreeding in Standard Poodles - By Dr. Armstrong
Standard Poodle Life expectancy with different levels of inbreeding.
Blue diamonds: Inbreeding COI of LESS than 6.25%
pink squares: Inbreeding COI of 6.25%-12.5%
red triangles: Inbreeding COI of 12.5-25%
black circles: Inbreeding COI of More than 25%
The Broken Black Line Represents the 'normal' survivorship curve of a non-inbred population
(The solid line is fitted to the more than 25% group.)
Why is it so difficult to find a Standard Poodle with an inbreeding Coefficient under 6%?
- the vast majority of Standard Poodle breeders still consider inbreeding to be acceptable.
- Inbreeding was once considered the ONLY way to breed a purebred dog.
- It was theorized it would double up on all the good traits of the parents and those pups who exhibited poor characteristics as a
result of this inbreeding were culled (killed).
- Breeders rationalize using inbreeding to obtain quick cosmetic results - ignoring the dog's health in favor of color, coat or
conformation improvement or simply to win that blue ribbon.
There are a small but growing group of dedicated breeders who are refusing to inbreed their beloved dogs.
Paris Poodles is a dedicated breeder who refuses to inbreed.
What does this graph show?
- The least inbred group (Less than 6.25% Inbred) survive, on average, 14 years --
approximately 4 years longer than the most highly inbred.
- A Standard Poodle with an inbreeding COI of less than 6.25% will statistically
survive as long as a NON-INBRED population.
Therefore an inbreeding COI of less than 6.25% should be
the MAXIMUM acceptable inbreeding Coefficient!
|Inbreeding has been extensively studied in other species.
The professionals in those areas also agree that a low inbreeding COI is imperative:
Inbreeding in Cattle:
TRAIT PERCENTAGE WHEN INBREEDING DEPRESSION OCCURS
Milk Yield 3%
Calves born 4%
Calves weaned 10%
In Holsteins a 10% increase in inbreeding has been shown to decrease milk production by about 270kg annually
Just a 1% increase in inbreeding (that is, a 1% increase in the probability that a calf receives the same gene from both parents)
results in a measurable decrease in milk quantity and quality, shortening of productive life, and increase in calving interval in studied
breeds of cattle.
Strive to keep inbreeding below 5% per generation. As the coefficient of inbreeding (COI, the
degree of relatedness) increases in a flock, inbreeding depression may occur, during which
fertility, growth, and other reproductive traits tend to decline. Such declines are especially
dramatic when the COI reaches or exceeds 30%.
Inbreeding in St. Croix Hair Sheep:
Inbreeding In Race Horses:
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