On Jun 4, 2015, at 7:45 PM, Andrew Rodger via wrote: > > On 04/06/2015, at 5:23 AM, Bart Simon via wrote: > >> >> Hello: Just wondering: A father [AF] has a son [AS]. The father [AF] marries the dg [BD1] of Mr. [BF] in 1900. The son [AS] then marries the other dg of Mr. [BF] being [BD2] in 1901. Or simply, a father and son marry two daughters who have the same father. No law is broken there is it ?. Bart [!!!] .... I can not seem to keep up with the befuddled-thinking kinds of laws over the generations. Since neither of these couples is related by blood - genetically - only by marriage - there should be no restriction. But the laws are not always logical:-) In any case, inbreeding has to do with the number of homozygous genes and not the closeness of blood relatives, if you are looking for healthy pairs (in any species). You can breed two sibling cats together who TOGETHER can produce high heterozygocity, and the offspring will not be inbred, even if the parents are inbred. And you can find two identical looking but unrelated cats and breed them together and get all inbred kittens. This is where "looks count". Each kitten/child gets one gene of each pair from each parent. (It used to be thought the gene from each parent was a random chance for each but it is not.) The gene pair so formed in the kitten/child either has two genes the SAME or two DIFFERNT genes. Looking at the entire individual's set of gene pairs, the one with the most DIFFERENT pairs (heterozygous gene pairs) is the LEAST inbred, and the one with the most SAME pairs (homozygous gene pairs) regardless whether the two were related or not, is inbred. Heterozygocity causes strength of individual and of immune system, robustness of health, and overall disease resistance. Homozygocity causes ill health, weakness, lack of robustness, smaller size, and poor immmune system. A smart breeder will look for as many DIFFERENT features as possible between whatever anials they wish to breed.' For example, wide ribcage and deep ribcage, not two the same. Long torso and shorter one, broad hips and narrow ones, heavy boning and lighter boning etc...looking for DIFFERENCES all within the breed standard...but with maximum variations. The resultant animals will be stronger, bigger, healthier, emotionally stabe etc, and will look good at shows as a result. Opposites attract, is a good rule here:-) It is the same in humans. I have visited some little towns where people supposedly unrelated marry, but the whole area is so full of the same genes that heterozygocity is impossible to attain, and there is high homozycocity in the entire population. The cheetah popupation is that way. There are so few different genes available to make heterozygous pairs that cheetahs are inbred no matter whether they are related or not. I recently worked with a conservation center where 3 of 8 cheetahs had died before I was contacted to figure it out. (The vet misdiagnosed a feline illness); They actually died of copper deficiency. Only one other animal of another species died, (an Africa lynx- caracul) but 3 out of 8 cheetahs died. More than 36% deaths in one incident is a lot for such an endangered species. Yet ALL animals (and humans) were copper deficient. Turns out the desert soil where the center was located, (in UAE) was almost devoid of copper and thus the animals used for food for the wildlife center, were short of copper, and there was essentially none in the diet. The two tigers who gave birth had no milk (it needs copper), but none died. A young lion got ill but survived. Only low heterozygocity cheetahs actually died before the problem was understood...they are like the "genetic canaries in the mine", the first to show ill effects from ANY health issue. Ill health of offspring is thus due to homogygous gene pairs NOT due to relatedness. In general if unrelated folk marry they should be mainly heterozygous, but if they live in a small population (as in a small area of a new country) or in a small population that is stable with little migration, it does not necessarily follow. But we know this now - nobody knew it a couple centuries ago. And laws do not necessarily keep up. Namaste, Irene -- Irene de Villiers, B.Sc AASCA MCSSA D.I.Hom/D.Vet.Hom. P.O. Box 4703 Spokane WA 99220. www.Furryboots.info (Info on Feline health, genetics, nutrition & homeopathy) "Man who say it cannot be done should not interrupt one doing it."