6. THE GENETICS OF THE ITALIAN GIANT FRILL index.htm
It is these "hoods" that have led me to conclude without doubt that what is involved, in the case of these and other typical features of the Italian Giant Frill, is an evolution based on quantitative heredity, as with all the remaining ones transmitted by the Parisian progenitor, but with the ìinterferenceî of one or more factors that are exclusive to the Italian Giant Frill. Taken together, they are responsible for the forward-facing direction of the feathers of the three curls.

In other words, the Italian Giant Frill emerged due to the small mutations that made the Parisian so great, plus the three new ones that more or less completely substituted the typical ones of the Parisian and which are the result of the above-mentioned tendency of the feathers to be turned towards the front. The more numerous the small contributions responsible for the quantitative heredity, the more the features are typical.

But let's move on to my first observation.

Mating pairs which both have a complete hood produces in the offspring a hood that is a little narrower than that of the parents, as if this energetic "forward-facing tendency" has impoverished the space occupied by the side feathers of the head. As I breed a lot of Italian Giant Frills every year, I have been able to establish conclusively that pairing a bird with the most typical complete hood with one that has a less typical head plumage - a partially-hooded one, specially in the centre - results in offspring with a hood of maximum typicality.

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