I am quite aware that in late years evolutioniste have re-defined their pet theory in this way, because if all you are talking about is the porportional distribution of alleles, evolution can be clearly demonstrated.
This is the definition that has been in use for the last half-century. Perhaps you consider that "late".
But if you include the rise of alleles that did not previously exist
New alleles arise through mutation. But, as I said to mark, the presence of new alleles does not necessarily result in evolution. On their own, new alleles merely add to the variability of the population.
and their spread through a population to the extent that new genera exist,
New genera come into being as new species come into being. No new genus comes into being apart from the species of which it is composed. In a way, one can say that macro-evolution and speciation are identical, for the only new natural unit ever produced is a species. Everything above species is a taxonomic label generated for human convenience.
What can happen as speciation within a genus continues, is that the group once known as a genus will be re-classified as a family, so that some sub-groups within it will now be given the label "genus" in respect of species within the former genus (now family) that are more closely related to each other than to other species in the larger group.
Note that our new allele might actually not be spread through the whole family (formerly genus), and that the new genus is merely a classificatory convenience. The only natural new units ever generated in evolution are species and sub-species.
this has never been demonstrated to have ever happened. It exists only in theory.
Speciation (defined in populations that reproduce sexually as "reproductive isolation") has been demonstrated. Speciation in other groups is defined less objectively, but within the limits of such definition has also been demonstrated.
In my university years as a senior level Biology student, I saw again and again the fact that the only REAL reason that evolution was almost universally accepted was because the only reasonable alternative was a creation of some kind.
That is a shame, but I think Christians tend to bring it on themselves when they refuse to define creation in a way that is consistent with the evidence in creation. We need to be more articulate about the what we mean by "creation" both in churches and in academia. There is no reason evolution should be seen as making a creator unacceptable concept.