THOUGHTS ON THEORIES
by Michael Feeney
First I would like to define what I am talking about when I use the word ‘theory’. According to the Oxford Dictionary a theory is as follows: “a formal statement of the rules on which a subject of study is based or of ideas that are suggested to explain a fact or event or, more generally, an opinion or explanation”.
For us in the pigeon world this in my thoughts relates to how we explain why a pigeon or pigeons excel at the type of racing they are competing in. Here we have the ‘Wing’, ‘Back’, ‘Eyesign’ and any other theory you care to use in order to explain why such a bird is good, bad, excellent or rubbish. I must admit that I find all of these theories fascinating as each in their own right can explain in some part how to identify potential candidates for the requirements each of us has for our birds. Whilst all these theories can be used to identify specific birds and what they can potentially do, they can also be contradicted. This is a fact and can be seen in all the other successful birds out there that do not meet the requirements of these theories.
I do think these theories have relevance in some part and do help the fancier, depending on which he or she has an affinity for. In all honesty, I think the use of all of these theories is relevant as long as the understanding is there that these are not fact and are just that: ‘theories’. These are not backed up with anything that is contradictory.
I remember seeing the video years ago called ‘Through the Looking Glass’. This was a scientist who was interested in human eyes and what can be found in them. He turned his view on pigeon eyes and visited umpteen lofts and found umpteen different champion racers and breeders. All of these conforming to the specifications inherent in the theory of Eyesign and all it entails. What I think this piece of study is missing is all those umpteen champions and breeders out there that did not match these criteria. I think there would be as many out there that did not fit the criteria. So what are we to think to make this kind of study more balanced? Really the answer is nothing. The main point to be aware of is that this is only a theory. Theories can be contradicted.
This goes for all theories that are out there in pigeondom. Theirs are contradictory in nature depending on what your bias and perspectives are. They are there to be proved or disproved and, in doing so, some will whole-heartedly agree and others vehemently argue.
Now, with that out of the way, we come to my thoughts on the subject. I have my own theories on how to progress and move forward and I must stress these are my own. I have come to them through a lot of research and discussion with more knowledgeable fanciers than myself. With a background in science, I do not say I am an expert or any such thing or with qualifications to back this up. I simply have an avid interest and do a lot of research on this subject to learn for myself. I am fully aware of the biology of genetic inheritance and in essence how it works, but can be contradicted or corrected at any time. Also, I do not say here that this is the full process of what occurs - only the parts I feel are linked to our aim as pigeon breeders. I hope you find it interesting.
With all the theories discussed around the world, I believe, none of them would mean a thing without the bird first having the correct gene sequence to start with. I think if we could identify which genes are responsible for creating that superstar bird as opposed to those that win and others that also ran. I think for us as pigeon fanciers, most of what we all produce are also-rans. We would be fools, I think, to believe otherwise. So why is it so difficult to produce that elusive champion? The answer, I think, lies in how difficult it is to get the correct genetic material to come together again. I will try to explain what I mean without going into language that will confuse what I want to discuss. Suffice to say there are two processes in which genetics are divided.
The first of these is called mitosis and is what occurs in every cell in every living thing in the world. For our purposes we are not concerned with this process other than to know it is the dividing of a cell into two halves. Each part carries half the cell material, i.e. genes, and the cell fully divides, creating two cells. The genes in each cell then copy themselves therefore getting back to the original number of genes. It by this process of dividing and multiplying of cells that all animals grow from the female egg to the eventual adult of the species, whatever that happens to be.
The second process which we are concerned about is meiosis. This only takes place in the sex cells of a species. In this process the sex cells divide into two and then each further subdivides into two more, leaving us with four cells. Two of these actually become redundant and are used for another purpose leaving us with two cells of sperm or egg. In these we hope the genes of the elusive champion can come together and produce another champion. And in this process is where the difficulty lies.
Let us look at the sex genes of the cock bird first. He is what is known as a double X. This is his genotype (gene makeup). If we accept that he is then XX, for example, we can work from there. He is given the tag of XX because under a microscope his sex genes are in strings known as chromosomes and these look like an X - like two strings attached in the middle and floating around. Also, it is important to know that each of these strings is also a double line. During the process of meiosis the first thing that occurs is that all the chromosomes double and then each set moves to either end of the cell. At this point the cell divides in two. From here the X strings separate giving, for our purpose, four single strings or strands as they are known. From here the cell divides again giving four cells from the original one. Only one of these from the male can combine with the female to produce one whole again. This diagram may help in seeing what I am talking about.
In the female sex cells the process is exactly the same with one difference. That is that the female genome is that of XY and not XX the same as the cock. In this case all of the young from a couple have the Y from the female and the X from the male. Whereas all the male young have an X from both cack and dam respectively. In my thoughts this is where the conundrum lies. I believe that the gene we seek and want as pigeon fanciers are located on these sex genes. In order to duplicate the cock’s genes in this manner we should simply be able to mate him to a daughter which would have one X from her sire. This is what we want, to recouple his XX. It is not so simple, however, as we all know.
There is a further complication here: another process known as ‘crossing over’. This is in actual fact why I think nature is against is in the reproduction of our wanted champion. On a basic level what happens here is that before the chromosomes separate, they may swap some of the genes we want. In this case it breaks the sequence that we need to produce that ultimate superstar again. If the sequence we want and need is separated in this swap it may never come together again. At the same time this swap of genes does not always happen at the same place on the string and sometimes the ones we want are left together. This does not automatically mean a superstar is born, as we all know two parents give half each to their young. Here is a picture to show what I mean:
As can be seen by the colour coding, part of the chromosomes are exchanged here. If this happens where the genes that are needed to make that superstar then a superstar will not be born. Let’s take the following as an example:
A G C T G T T
T C G A C A A
If this is the exact pattern of genes a superstar has and in crossing over these change and swap then the sequence is not exactly the same as seen below:
A G C A C A A
T C G T G T T
To reproduce the champion the exact copy must be created in this case we can see in colour again where the swap happened breaking up the letters we want. This I feel is why it is so elusive and difficult to reproduce that champion again.
Another complication is that when we are breeding both parents do not have the same genetic make-up, although both may be champions, and so that can lead to further difficulties. When there is a 50 50 mix of both parents the young we are hoping have the genes we want. This may or may not be the case in the young but again we can help nature along by inbreeding to the desired champion. The aim here is to fix the desired genes so that they are always present in the sperm and egg no matter what happens. To do this though is very difficult and arduous and time consuming. It is done by taking the young off super pigeons and mating brother to sister for several generations.
Now there are doubters out there that say this can be done and who believe that the inbred offspring would be no good for racing. Of this I have no doubt, that they will be no good for racing, but the aim in this project would be to produce breeders with exactly the same gene make-up, so that no matter what mating they are put with, the genes we want will be there. Again you may say this can’t be done, but the examples are the likes of bulls for beef production that are genetically modified for lean meat growth. Another is that of laboratory mice and rats that are inbred for hundreds of generations to produce this kind of animal for testing purpose. Our aim is also for testing - just a different sort of testing. We aim to produce a bird or birds that can always pass on the genes we want to their offspring. This is an idea I am going to test myself.
I understand that there are pitfalls and dangers involved in inbreeding, that the bad as well as the good more often come out. This is where a strict selection process must be followed and that all birds not being subsequently used are removed from the process. The strict selection will be carried out by breeding about twelve young from each subsequent generation of brother x sister mating. In doing this the aim is to give myself a choice of young to pick from. This will hopefully let me eliminate problems one at a time at a genetic level and increase the positive aspects and make them permanent in each generation. This will be a long process and one I am willing to do. I already have the birds in mind to use for this process and from this hopefully we will see progress. I will keep you all posted.
Elimar - December 2014