UNder conventional evolutionary theory, there is a falsifiability test, although it is complicated. When the scientists finish mapping the genomes of what they believe to be related species, they “simply” have to show how to start with some common ancestor, and then through a series if individual mutations, map gene sequences from the ancestor to both final related species.
With the stipulation that at EACH step on the way, the resulting organism must be viable and reproducable, and it would help if it was an improvement over the norm so it had a reasonable chance of reproducing.
It is my guess that they will never find the path from one species to another, but that is because I don’t believe you can go from one to another through a series of simple step mutations ALL of which are viable, reproducable, and selectable.
However, if this new theory is correct, they won’t have to find the series of mutation steps, because there won’t be one, just this rare huge change.
.....if this new theory is correct,....
I don’t think it is new.
It is remarkably similar to Stephan J Gould’s Punctuated Equilibrium. It is a matter of fact just some tinkering with that theory.
The fact is, there is no certainty precluding several different evolutionary processes.