population genetics for pigeons fathers (Part 12) I'm still criticized in my last blog post, the quality of the magazine "The Pigeon", and then I read today in the 49/08 turn contribute to the topic of breeding and, moreover, one that I think very good. The title of the article is "men talks" and it is essentially a discussion of the author with the two icons breeder Harry Tamsen and Günter Prange.
I find the article very well because it reflects the experiences of two very experienced breeders on breeding, and doing some very useful conclusions can be drawn. And in addition, the article an excellent example on how we receive information that we should judge of top breeders, pigeon experts, breeding experts, blog writers, or who receive :-) Anyway,: Curious, open, but always critical! (As I said, this applies to the same extent for my blog posts, reader!)
Tamsen Harry has many things in the article, very true words, I think: first
If you mated average dust with very good pigeons, but is never very good out here!
second Flock of pigeons which fly by abandoning in smaller local groups like learn how to minimize losses, but in the long run of the requirement that we must separate from the flock of pigeons, not conducive. As a consequence Auflässe therefore be sought in larger composites.
third Frequent Umpaaren helps to identify the "strong heredity," doves. And only this one should continue to work preferred.
In addition, I was particularly impressed by Günter Prange. Above all, because he has retained his statements, even if some statement of Harry Tamsen at one point or another almost invited to a contradiction. But what he said had weight. In particular, I think his statement is emphasized that is the character of an extremely important and the rest of hereditary property of pigeons in Selection must be taken into account, for he makes the really good pigeon. For my part I will summarize this term such things as curiosity, learning ability, territoriality and breeding behavior. The word "stubbornness" that Harry brought Tamsen at this point in the game, I personally can not start as much as I find it hard stubbornness and lack of ability to learn to separate cleanly. Further evidence of Günter Prange I found very valuable, such as that we should inflate its stock does not, so you do not lose track of the breeding goal in mind and that patience is very important and that much even with him just was lucky.
get
criticism
But as already mentioned, the article is therefore also very good because it shows clearly that we believe the information we receive about our sport from others, always verify critical need, even if they come from such breeders icons.
Specifically
Harry Tamsen is very generalized, in some statements that his long experience, probably his success may be the opportunity for that. But surely, since that brain of man is always happy when it detects patterns in the chaos to which it can talk. And if a plausible model for us, it is for us the "reality" is among the many things we are classifying, even if not always logical, and thus is not always correct in the sequence.
So is the first statement Harry Tams, that the average dust paired with very good pigeons practically never very good result, certainly arisen as a result of his experiences and observations of many farmers, whom he met over the years, and is therefore valuable. However, his argument that this effect is probably instrumental in the inbred pigeons is worse, many farmers operate, is not conclusive. It could be a reason if it were the case that many poor farmers would operate long inbreeding in "its own juices." But would then be already achieved significant levels of inbreeding on these breeders, so that reasoning does. But in fact, but also the unsuccessful attempt to introduce something new, only just failed.
It is precisely the population genetics of a very good explanation for Tamsen observation and, moreover, a scientifically proven! In the performance properties are essentially quantitative properties by an accumulation of as many good genes (almost always are the recessive alleles [allele \u0026lt;-> name of a gene variant] ) can be increased (see see also former Blog article in this series). A recessive allele will only be effective if it homozygous, thus appearing to each of the two chromosomes of a chromosome pair.
The destructive influence of mediocrity
The probability of an allele homozygous (homozygous) in a population occurs depends of course on the frequency of this allele from this population in which I'm putting together combinations. If the population is large enough and well mixed, one can calculate the correlation between the frequency of an allele and its homozygosity. This calculation formula we have given the researchers due to Hardy and Weinberg. And even if our Population is mixed not Pefekt, and relatively small, gives us the result of this calculation still a good idea of where this is the basic problem:
shows the red curve, the percentage of animals, a feature showing visible when we consider a single recessive allele. If for example 50% of all animals carry this allele in itself, probably 25% of all animals of this allele present homozygous and thus show the corresponding property. Only when more than 70% frequency of this allele in the stock shows at least half of all animals that property.
But we are dealing with so many recessive alleles that a property such as high speed flight . Determine And it would be only 10 alleles, which would be relevant to the particular quality of an ace bird, and these 10 were sitting on 10 different chromosomes, so that they would not inherited in one step, but independently of each other, it follows that the probability that "act" in an animal all the genes the blue curve can be used in the graphic. And that is remarkable!
It shows that we have this, not even very serious conditions (namely, there are certainly more responsible than a 10 genes for an ace-pigeon) is a probability of only 0.1% once such a As to breed pigeon, even if all Doves in the population of all these important genes with a probability of 50% carry with them! Even if already bear 70% of all pigeons these important genes that are subject to our chances of an ace-pigeon of this kind at just 2.8%. This is so very dramatically illustrates how strong decrease already a little dilution from very good genes in a herd our chances of good young talent. And that's why you should only use very very good starting point for breeding and that is why insertion of top pigeons out practically in a group of moderate doves never a success! Tamsen Harry is absolutely right, but from an entirely different reason when he mentioned here.
year-old deaf and Umpaaren
Another, again and again to read thesis is that is drawn from years of pigeons better than from older ones. In the bold formulation of Harry Tamsen this will become even said that at the top of a beat at least one pigeon breeder was that age and have the parents (quote) "never" brought similar good siblings. Now again the joy of proposing a made by observation experience Harry Tamsen probably a trick. This observation is applicable not only to rule, but is already equal to only.
As a critical reader pigeon breeder and you should allow for the Breeders' icon simply Hide, and his descent folder get out of the closet:
The parents of Rambo, a travel-As were by van Dyck 4 and 5 years old. The Rambo brought Het Laatje both Kannibaal and the Bourges. Both travel and breeding aces. Here the parents were 2 - and 5-year! The parent bird at
Joop Koch, the "light of Orleans" was 6.nat. Ace Pigeon, his father was 9 years old, his mother two years old. He went with the "wick Belg" in solid pairing several years a 1.nat Ace Pigeon Short, a 3rd nat. Ace Pigeon Middle Distance and 9.nat. Ace Pigeon Middle Distance. The parents of the
Fieneke Vervoort are 4 - and 3-years old. They brought also the B-98-800, in the grains in Germany became a Topzuchttaube.
King and Queen at Andreas Drapa are 4 - and 5-year, as they took the 638, the 2002 1.As-bird was in Germany and they were already 6 - and 7-year-old when she and the another one in 1020 . As Bird and Olympic champion brought.
The parents of the Figo of Reynaert were already 7 - and 4-year, but they did have 5 - and 2-year-old Keizer, who also was 1.provinzielle Ace Pigeon and 14x1. Prices flew. They also brought some other top breeders, such as the "Small Figo" in Bosua. The car in Bosua
coupling consists of two doves, which also consists of 6 - were taken and a 4-year-old -, 6 -, 5. This breeding pair brought several As-pigeons, some of which, such as the Witkopje (best young NL) bred, was when the parents were the age of each fifth
I will stop here, otherwise it gets boring, but it could still continue as long as everyone understands the basis of race famous pigeons themselves! As it can come even with such an experienced breeder of such a miscalculation? Now, I think, something always happens when one does not consciously statistical effects. In the present case: Almost all stocks have a large proportion of pigeons year (often holding a stock). Therefore, it is also the case that involved a lot of pairings years of pigeons! You become 'statistically advantage. To form an opinion, one must not judge the number of good pigeons from pairings with years of pigeons, but put the number of such birds, first in relation to the number of such pairings. And only then can we compare this ratio with the corresponding ratios of the comparison group! And if the years of pigeons of a beat not by better health advantage, which for a consistently healthy stock should not be the case, we should expect quite clear that all age groups is approximately cut equally well, because the inheritance laws do not depend on age ( apart from very, very rare environmental influences on genetic material, such as mutations or epigenetic effects)!
And the rare occurrence of two aces in a pair is surely more of a statistical effect. It is already very rare to pull an ace out of a couple. It is once again just as rare, if I move a second ace of the same pair. By Umpaaren I increase but not these opportunities. This tells us the population genetics! This is apart from Umpaaren yet to identify a dominant sire a lot of sense. And here I would agree with Tamsen again.
forget sexes!
At another point, it trashes Harry Tamsen then really. Namely, as he the female offspring of a bird and the male Offspring of a female subordinate, it would 75% of the hereditary characteristics of the respective parents lead animal. Of course this is absolute nonsense! Of the 40 chromosome pairs of young pigeons are always 40 chromosomes from the father and 40 strands of strands of the mother.
It shows very dramatically, as can be very very good and very experienced fanciers pigeons, relevant literature and the traditions are shaped on breeding. Again and again, not scientifically tenable statements are made that consider the performances in pigeons essentially as sex-linked inherited (see my previous blog article).
But there are even some evidence that the essential performance characteristics of pigeons NOT be inherited sex-linked! How do I get this bold statement? Now, with "sex-linked" is meant so that the genes of these properties only on the Z chromosome (one bird with two, a female one), or only on the W chromosome (which carries only the female one) occur. If it were recessive, these properties could only be effective in birds show when it is present homozygously. Females, however, have always only one Z chromosome. It is thus here a recessive trait which is pronounced to be on this chromosome, since the "counterpart" in a second Z-chromosome missing. As a consequence, this has consequences for the frequency with which she loses any characteristic for days, it would have to prevail in fact more common in females. Now, if key performance characteristics that are recessive nature, were inherited sex-linked, would be superior to the birds, the females on average. The analysis of the AS-scores of the Federal-AS-pigeons in recent years, we recognize, however, that there be no difference in performance is!
But what if key performance characteristics were inherited sex-linked dominant and (it therefore needs only one Z chromosome, or only the W-chromosome carriers of the allele to be) would these dominant characteristics in performance-based selection of racing pigeons for centuries have been subject to enforced so strong that only very rarely should appear pigeons, which do not possess this allele. For each offspring, the so does not have an allele is, yes, right on through lower power and can be selected.
The thing with the 75%
by inbreeding it is quite possible, however, to breed pigeons that transmit secured 75% of the genome of their ancestors to descendants. This is in fact at an inbreeding coefficient of 50% of the breeding animal is the case (see also older blog posts on this topic)! He would, however, a multiple extreme inbreeding have preceded. How to reach this inbreeding coefficient, for example, if three consecutive generations of full-sibling pairs were complete. These animals then contain a Genmix their original parents (ie father and great-great-mother) is concentrated.
strong One might as well concentrate the genes of these two great-parents, if one roughly six generations in a row takes half sibling pairs, which were always paired together in this great-parents in line. This requires man 7 half-siblings (one by one sex [points to his parents to the inbred focus] and 6 of the opposite sex [per Inbred generation one]) This 7 half-siblings should therefore each have different parental counterparts, otherwise, the genotypes of the addition would occur more than once ancestors "concentrated".
could And as a third alternative, a roughly 10-fold return repeated pairing of children in one breeder and concentrate the same genes that single parents comparable animal. But I doubt very much that all these paths are breeding really useful. Because we would of course very strong risk that particularly all the bad genes were transferred to a dove, and concentrated. Moreover, in each generation would have even made an extensive breeding examination, so that solely on already time problems would arise. And finally, the inbreeding depression would most likely seal a very early failure of our efforts.
And so is the also the note by Günter Prange in this article again very valuable that we have to maintain the strain pairs very closely. But he would like to point out that he currently at eg 6 inbred such products in its inventory for a long does not consider that there was only one among them who inherited the good qualities. They all need to put to the test! And even if I already warned in so many places in my blog before the close of appearances with intrinsic value of a dove I: At this point, the selection of inbred products as an approach can be helpful. Even that has Günter Prange out in this article.
For each characteristic of a family pet, we find a direct descendant inbreeding indicates to us that at least the chromosome strand, on the "settled" for this characteristic was passed. And if we're lucky, it is precisely this chromosome strands that lead also important for the performance characteristics with them. So if very many of the features match, our chances are better, "get" the master pigeon.
population genetics for deaf fathers (Part 11) 
I must admit I am a Sponger. Every few weeks I have already read the bum copies of the magazine "The Pigeon", which my father still refers regularly. For me there was a reference to the "Journal of pigeons customer" as they are conscious of tradition still calls, since my re-start of 2006 the question.
For one, as I can so so nice bum with my father, on the other, as they unfortunately their claims to be a brieftaubenkundliche magazine, is rarely just. Too often, especially in autumn, they degenerate into a lobbyist Journal of the various camps in the association, and also the year the identical articles on topics such as "care in the Mouse", "Preparations for breeding, "" care and treatment of youngsters ",... I need only a simple version, and read again and again.
But in the 45/08 number surprised me with an article entitled "How to breed ? right "And the author of the article seemed academic weight to throw into the balance.. Prof. Dr.-Ing Gerhard Wächter Only I would have wished, however, that the editors of the magazine educates its readers about whether the academic title of author in connection with an activity in animal breeding area have been acquired, or instead, such as construction of chemical reactors. Such information would be given the force of a jet Professor Title not unimportant, because all too easy for the reader might be inclined to throw his criticism on board, as it is, after all, is a professor.
Well, I'm no professor, and in fact I have good chemistry on chemical reactions more idea than animal breeding. However, I would like to make some critical comments on this article because he is one of the rare items indeed dealing with the theme "Breeding of pigeon" in the context of population genetics:
First of all, you can see in the article the academic functioning , such as those common in higher education is: Do not write anything for which you have no source can specify, or you have not figured out myself through research or shown. As a very positive result, the author gives the reader a comprehensive list of comprehensible literature on the breeding of racing pigeons to the hand, which alone is worthy of praise. For even if not all may be references to the past state of affairs, or in substance, even now disproved, it is always advisable to have read such things in order to form an informed opinion can.
And so the article presents a fairly good summary of some of these theses sources, so that even a lazy person has read anything about it. But against the background that the author is a professor and with the title indicates, he would give an answer to the question of the "right" Zuchtweg, which is merely quote from some outdated sources that represent the majority of any scientific work, but rather represent personal opinions of the authors, clearly not enough .
It is even dangerous, too easily, the reader of his answer to this question give the status of scientific knowledge, which must be right, even if a professor writes that. His answer to the question from the title (citation: "Duch about racing pigeons with average benefits resulting from the experience only from crosses in line bred strains), and his other statements about sex-linked effects, etc. but are actually in this form is anything but a proven general scientific knowledge, and again just a personal opinion of the author, which has little in common with the actual state of knowledge on the subject.
Specifically
The author presents very well that inbreeding is useful in combination with appropriate selection, clean lines of undesirable characteristics and to establish other desired properties. Also of note, that at the crossing of two inbred lines derived F1 generation (direct children) as hybrids often have a hybrid force, which is known as heterosis-effect corresponds to certain facts. And his statement that the way is the poultry breeding, such as keeping and maintenance of two separate inbred lines, which are then used for the production of utility crossings in the F1 generation of racing pigeons breeders are not very feasible because they require large stocks, in my opinion very good and even important at this point. But the author draws many conclusions are wrong, unfortunately, because of its absoluteness.
The statement heterosis would occur only if at least one of the two was inbred strains come together in a pairing is wrong. Heterosis is just a general concept in population genetics that describes the performance increase of a breeding property that crosses the (usually) appears unrelated lines or trunks. If the offspring of such crossing in the observed properties of the breeding performance of the respective parents are, this corresponds to more power to the so-called heterosis increase (see, for example Comberg, Leibenguth, and other textbooks on population genetics). The fact that the parental lines have to be inbred, but not a prerequisite for the occurrence of heterosis!
heterosis is rather in the increase of the junction of the genome Heterozygozität children explained to the parents. This occurs certainly at the crossing of inbred lines often, but also in other combinations, such as the "crossing wild" completely unrelated individual animals, which are themselves already emerged from such matings may occur this increase. Yes, it is failing even impossible (but much less likely) to occur in the mating of unrelated animals.
is the heterosis increase, however at the crossing of inbred lines usually considerably higher than at the crossing of animals, which in itself is already crossing products. But it can not but conclude, as does the author, unfortunately, wrongly, that the breeding performance of the product must be of such a two-crossing inbred lines higher than that of the wild intersection. Why? Well, not the performance increase is the decisive factor, but the absolute level of performance. By inbreeding depression, the inbred lines could be observed such as our property in the course of generations from 100 to 90 "quality points" to be dropped. The intersection of the two lines would bring such quality junior with 105 points. The heterosis increase would be significant with 15 quality points. But could the offspring of two non-inbred parents also end up with 100 points at 105 points! The heterosis would be less the result However, equally strong.
And the fact is, not only know all knowledgeable pigeon fancier, but it also show the countless family trees of As-pigeons and service providers. Consider, for example, only the family trees of the blow Koopman. As a starting point were chosen here, in fact, essentially two inbred parent lines: Janssen and Van Loon pigeons. And the dust crossing the F1 generation, such as Eric or Beatrixdoffer showed outstanding performance. But the approach of the author of a junior following the F2 generation and the majority of the offspring of later generations have shown a worse performance in Koopman, since they provide no inbred Pigeons. Pigeons as the gentile, the Jacco and many others even national ace-pigeon show at Koopman to the present the opposite!
So: The statement of the author that bring previous inbreeding and outbreeding better racing pigeons, as is breeding other ways not only not scientifically valid, but also thousand times refuted by the practice. For the hybrid force, only a high heterozygosity is important, even where this may happen more!
also is not alone Bastard important strength for a very good racing pigeon, but also the high "density" of good genes in the genome of the animal. Because there are properties, such as the vitality (Or egg production in chickens) are attached to the hybrid force, and there are properties that do not or only to a limited extent, be due to additive gene effects.
This leads as well as the unresolved basic conflict in the breeding of pigeons, which makes it so exciting and prevents a clear answer to the initial question of the author:
for the focus of additive properties would be a high accumulation of the positive genes desirable that can also lead to an increase in homozygosity. For the hybrid force, however, a possible high Heterozygozität of the genome is desirable.
And so there It subsequently also in two "worlds", inbreeding and crossbreeding, excellent breeding stock and breeding pigeons. Shall place at the famous "Figo" by Reynaert or constitute the "Daisy" the Stieneckers strong inbreeding products, which still services being the best. Here, the inbreeding may have been the enrichment of the positive genes, but without it herauszuspalten negative recessive genes (homozygosity for this to lead). This is a cross between this Inzuchtiere with other, unrelated animals that show the homozygous "harmful genes," canceled, would not have been necessary to achieve top performance. On the other hand, the "small" by Vandenabeele an absolute cross product, and even his Parents were hybrids. He rendered himself very many very good flyers, like the Wittenbuik, the Turbo, the Picanol, ... (Which is indeed could be attributed to the hybrid force of his also in cross bred kids), but he and many of his children and grandchildren were still improving sires, the Little itself could even one of the best sires have been the seen of pigeon racing today added. And that although he and most of his children no inbreeding is directly preceded it. When little ones were so in spite of the many intersections in the run to the very good genes extremely concentrated!
luck and chance are very very important factors in breeding excellent pigeons. Therefore, the "ideal" breeding strategy can only be constantly on hand and the situation in matching strategy, which relies on the means crossing and inbreeding, without slavishly stick to unsubstantiated schemes.
about all this, the author makes several references to sex-linked effects, in which he writes as: "The hen is critical." And he leads the "Bruce Lowe'sche law" which refers to or Vansallen that attaches to the exchange between the sexes in a breeding line meaning. All three points should not also be left without comment:
Bruce Lowe, an Australian who in the 19th Century horse-breeding, the introduction of family number system structured, has formulated a scheme in which he suggests should be used as horse breeding family. This scheme to raise the "law", which also is still valid in pigeons is not only incomprehensible but very unscientific.
The author postulated that due to the fact that gender is transmitted among birds by the females for the conservation of the properties of a family pet should be zurückgepaart in the female line. Naturally, this statement, in the later reference by Vansallen. However, it is not about the question of whether certain chromosomes ever transferred to the descendants be, but the question of whether the carry one of the two paternal chromosomes Z "following" secured after the copulation.
is still not clear which and how many Gene on the sex-determining chromosomes of the pigeon sitting, and there is only one of a total of 40 chromosomes in the genome of each pigeon dar. After the independence law of Mendel, all other 39 of 40 chromosomes independent of this one inherited. What sense would it make a breeding strategy that is on only one chromosome from 40 to align? The statement that the previous pair was necessary in the female line to the (note the general wording!) Properties of a family pet to get is factually incorrect! On all 40 chromosomes of the pigeon are coded properties and since it is of no particular sex-determining to "follow" either, because of the other 40 chromosomes of the parent animal at each mating definitely some fall by the wayside.
cited at this point, the author also Vansallen (of the very good books and articles I am a big fan by the way). But in the cited source was undergoing Vansallen the temptation to concentrate on the transparency of the inheritance of the Z chromosome, the other 39 chromosomes should be ignored. In this circumstance, the translator, Dr. Arno Meyer has nevertheless expressly point in this book to just Vansallens to change all that. Can it be that Mr. Prof. Dr.-Ing. Guardian has read about this on purpose, because it would not follow his argument had they? And finally
are sex-linked inherited power characteristics of my knowledge in pigeons to date neither Identifies yet been demonstrated. And I can only recommend that the generations of mating only as an aid to tracking of a paternal chromosome-Z to see. Nothing more, nothing less. One might as well take advantage of the presence of another dominant feature (eg the gray color) to "persecution" of the chromosome strand is sitting on the gene for this purpose. What so should be slightly Bring long as it is unknown what other properties are sitting still on the "persecuted" chromosome? In individual cases, like one or the other observed coupling be a desired performance property traceable to the property will help but should not and can not build a general breeding strategy then!
should therefore readers of the article by Prof. Dr.-Ing. Guards to make the breeding in the future more difficult than it already is, and not move the gender shift in mating the center of their breeding efforts. Something does, if at all, only a very minor role in breeding excellent pigeons. And "Bruce Lowe" is an opinion of a horse breeder without any evidence, nothing more!
Another note which also fits the theme: At some point (not mentioned in the article), emphasis is placed on the so-called dam in pigeons. This is justified by genetic material, which is not stored in the nucleus, but in the mitochondria. This genetic material is always, and Although complete and unaltered, transferred only from the mother to all her children. This carries all the birds of the mitochondrial DNA of the females who appear in the classic pedigree representation at the bottom "edge." The question remains whether this fact should attach significant importance in the breeding of pigeons by trying to obtain certain mitochondrial genes in the portfolio.
To date, little is known about the functions of the mitochondrial DNA. Very large, the genetic code is not there, but compared to the nucleus. But even if this direct effect would have on the performance characteristics of a dove, after centuries of pigeon breeding and selection for their expected performance is not that we still face "worse" genes mitochodraler a pigeon. For each pigeon in existence today will be on this bottom "edge" of the family tree sometime in the past (and it was 30 generations ago!) On an outstanding or excellent breeding hen Reisetäubin . Meet And it is their mitochondrial genes could be so "bad" not been, and is found today in the same order (from very rare mutations apart) in the genome of the observed presence of dust.
So, I personally do not see any need to lie down on the mitochondrial genes more attention than all other genes. No, quite the contrary: The very high "stability" of these genes over-four generations and the centuries-long selection, I see in pigeons even many legitimate reasons to have them ignored.
might be a competent professional editing such articles, such as that of Prof. Dr.-Ing. Guard against the impression for example, by Hr. Dr. Kamphausen or universities with which the federation in terms of research in communication, for the future makes sense for such a factually incorrect, but can be avoided, scientific evidence looking article. And if it appear even more often true professional articles on the subject of pigeons, I would imagine even one day see "the pigeon" to scrounge no longer with my father, but to refer themselves.
shows the red curve, the percentage of animals, a feature showing visible when we consider a single recessive allele. If for example 50% of all animals carry this allele in itself, probably 25% of all animals of this allele present homozygous and thus show the corresponding property. Only when more than 70% frequency of this allele in the stock shows at least half of all animals that property. 
