American Pigeon Journal
July 1985, pages 19 & 20.
"Wildtype", The Unimprovable standard Barred Rock Pigeon
by Robert J. Mangile
The Webster's New World Dictionary gives one definition for the word "standard" as: "something established for use as a rule or basis of comparison". Living things seldom express the absolute perfection outlined in a standard,. but they can be compared to one. That is an important point to remember when studying pigeon genetics because sooner or later you will stumble onto the term "wildtype"
What on earth does that mean exactly? Well, exactly... might be an improper word to use here, but wildtype means "genetic standard". Allow me a shot at explaining, OK?
Rock Pigeons display many variations among their numbers scattered throughout the World. The argument rages on yet, as to whether the earliest forms were barred or checkered. That is mostly unimportant at the time. What must be established is something that is universally appreciated. Fortunately, for the interested pigeon fancier, this has already been done. Science has established that the "standard" to compare all differences in pigeons would be the blue barred Rock Pigeon. That means "wildtype" is everything expressed on the established standard of a blue barred Rock Pigeon; i.e., clean legs, plain head, orange eyes, smooth plumage, 12 tail feathers, etc.
Many breeds possess 12 tail feathers, clean legs, plain heads, blue-black color, and barred wing shields; and when compared to wildtype there is no difference for those traits. Dwell on the differences, like extra tail feathers, grouse legs, crested heads, red or brown color, and checkered shields.
To assist comprehending what wildtype means, consider an automobile turning in front of you at an intersection without displaying a blinking turn-signal light. You have expected and accepted that all cars not displaying a blinking turn-signal light will go straight ahead. So..., what does this have to do with pigeons and wildtype?! Well, the automobile's sudden change in attitude was not standard; and may be comparable to a single Rock Pigeon in a large flock, displaying any characteristic not considered to be standard. The important thing to remember is that we did notice the difference in that single automobile's movement at the intersection. Occasionally, Mother Nature goofs-up and the structure of a gene changes. Such a change in the germ cells gave rise to the grizzled plumage. Changes of this kind are called "mutations" and are more permanent than the error of the automobile driver. Before civilization, such mutations occurred but went uncultivated. Fortunately, for pigeon fanciers, Man has cultured and perpetuated them.
For a better understanding of how designated wildtype plays a role in the study of inheritance in pigeons, let us accept that the symbol (+) be used to represent everything pertaining to a wildtype pigeon. All traits are controlled by genes; so, they (the genes) are represented with the symbol (+). Approaching the study from a totally ignorant position, we must assume that we do not know which gene(s) control which trait. We can observe that barred wings and orange eyes are separate entities but we do not know which gene is responsible for which trait. Therefore, we must assign the wildtype symbol (+) to every gene in every cell.
When we first observe a grizzled Rock Pigeon we notice that the grizzled appearance is the basic difference, with all other traits as they were in the standard wildtype. So, we label that difference and "only" that difference. We call it. - "grizzle". Not blue-barred grizzle, but simply grizzle. The only "difference" is grizzle, ... remember? We know wild type is non-grizzle barred! And, we need not worry which particular gene in the cell has changed or mutated to grizzle; but only that it has happened and can be passed on to its offspring. Of course, we must put it on paper for a better understanding of genetics in order to teach others. And, so..., begins our understanding of genetics, and how it works in pigeons.
There are numerous traits that differ from wildtype and to list them on paper might be simple enough. But when using them repeatedly, over, and over, and over again in our daily use, it becomes quite burdensome to write each one at length. For instance, with a grizzle blue bar we could easily write "grizzle"; but if it were a dilute, brown, check, grizzle, the idea soon becomes clear. We must develop a shorthand with symbols. So, letter symbols are proposed to represent each trait, much like abbreviations for words. To represent the bird mentioned above, we simply write; d, b, C, G. It seems troublesome at first, but so was learning to use the letters b..a..1..1 to represent a round object!
Now, if you are wondering how the change in attitude of the vehicle almost hit in the intersection has anything to do with pigeons, it is that the change (mutation) that occurred centuries ago which produced a grizzled wildtype is quite similar in that it differed from the expected norm and it left its mark. We keep track of the differences, not the normal or standard things; whether it be moving automobiles or wildtype pigeons. By-the-way, how may differences does your favorite breed of pigeon display? Remember, compare everything, not just the plumage color!?
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