Wednesday, March 25, 2009

Terrierman blogged: Howard Galton's Bloodhounds

My Comment:

Terrierman remarks:

"What is only notable here is the provenance of the observation: Darwin's inquiry into the effects of inbreeding in Howard Galton's blood hound pack dates back to 1838, more than 20 years before the first formal dog show in the U.K., and 35 years before the start of the Kennel Club."
That means that as far back as 1838, Howard G. noticed how inbreeding fixed traits in a group of purebred dogs. Unfortunately he focused only on the one negative trait that he noticed was fixed (sounds like it was a tail kink, which is no biggie for concern).

Howard G. apparently wrote:

"I have found from breeding in & in that there is considerable difficulty in keeping up the breed. Many of the females have never exhibited any sexual appetite & those which do so at all, very rarely."
So he was breeding "in and in" and it was not until "at last I got a cross with one of Lord Aylesfords' Bloodhounds, since which time it has disappeared."

Howard G. was observing the power of combining (1) inbreeding to increase the liklihood of desired traits being present in the offspring with (2) outcrossing to increase the liklihood of defective genes being dropped and therefore absent in the offspring. In this case the outcross eliminated the occurrence of a tail knot in subsequent generations.

Terrierman uses Howard Galton's observations as if they are demonstrating a "bad thing" but in fact they only prove how powerful the combination of inbreeding and outcrossing can be to improve dogs when appropriate selection is used.

Howard's G.'s notes regarding bitches being unwilling to breed may be related to a number of possibilities:

"Theoretically", according to science, bitches should be programmed to be choosey, and mate selection based on the male most likely to produce strong, healthy puppies. There is apparently an innate tendency for female animals to use pheromones in mate selection and the tendency is for the female to select mates that are genetically different from herself. Of course, it doesn't always work this way, and in fact there are countless numbers of closely related (brother to sister and parent to offspring) accidental matings that occur every year in dog owners households. It may be that this trait has been lost from some bitches over the generations of past breeding. This could explain why accidental matings between close relatives occur in dogs or perhaps the males invloved are quite aggressive and determined. Or perhaps it is a flexible, variable, or even completely unreliable tendency that is consistent only under very specific circumstances such as randomly bred population? There are lots of questions to be answered here here.

But, regardless of why, very closely related accidental matings occur quite reliably in dogs when the opportunity arises. Howard G's bitches may have rejected his males due to their being too genetically related, or they may have just been bitches being "bitchey". Many young bitches and older ones as well are reluctant to be bred, and he may just have been observing this from his "1838 chauvinistic" point of view that females should always be open to sexual advances from males, and those that were not receptive were viewed as dysfunctional. A notion that persists amongst some men even today. ; - )

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