The
story of dragons is one shared by magical and non-magical creatures, evolution.
This phenomena defined as the change in the frequencies of allele in a population
is no doubt a non-magical event, but rather a very well described phenomena in
the muggle literature, by those not familiarized with genetics, allele are nothing
but genes and the many variable they might have in a population, such as a gene
that might encode for the pigmentation of a flower, but in another individual
what would have been the same gene is slightly different  thus providing a different pigmentation for
another flower, the change in a population of how many different types of
alleles there are is what is defined as evolution, there is however a misconception
in which evolution is pictured as the “change” from one “kind” into another,
the young wizards might find this possible as for them transfiguration of an
object or creature is very common but the origin of dragons was not magical as
there were no wizards in the time of their arrival which can be verified by
fossil records. The change from one kind into another is incompatible with the
understanding of the behavior of populations, constantly changing and moving
over millions of years, diverging and converging just to split again, never to
rejoin each other, this is the line muggles have drawn to define a “kind”, a
population that is never meant to rejoin and reproduce with another, let it be
clear that this does not imply well defined traits which we could use to tell
them apart from each other. Meaning that a “kind” or species as muggles have
defined them could look very similar or could look very different. One of the
few mechanisms by which a species gradually changes or evolves is natural
selection or survival of the fittest more appropriately described as the
survival of the creatures whose characteristics allow them to create offspring
and thus leaving them to them described by Mendelian genetics, just as your eye
color is determined by your parents the same is truth for all the traits which
you do not see and for dragons and their ancestors as well.