So-called macro-evolution is an invention of some Creationists who want to draw an (invisible) line that blocks evolutionary changes from reaching the level of a new species (a population that can’t breed with the original).
No one has ever proposed a way for the organism to know it has reached that bordered and promptly stop accumulating mutations.
bordered = border
The border, obviously, is the point where members of what was formerly one species are no longer able to successfully interbreed due to mutation. Mulism.
This is hardly an invention of creationists, but an internal assumption of evolutionism.
Your definition of a new species, while almost universally accepted, is flawed.
How would the first of a new species procreate if it can’t breed with the species it originated from? Did two of the new species evolve simultaneously, one male and one female? Is the first of each new species capable of asexual reproduction?