“In the same way, proponents of naturalistic theories of descent now develop "epicycle-like" explanations to resolve apparently falsifying data. While descent hypotheses could potentially be falsified by this data, these "auxiliary hypotheses" (i.e. punctuated equilibrium, miraculous genetic duplications and co-optations, lateral gene transfer, hopeful lack of data) do serve to preserve the original theory of descent. However, in the process, they force the primary claims of common descent, namely the fact that all organisms are related through ancestry and evolved by mutation and selection, into an unfalsifiable position. “
“In his book, Kuhn notes that a theory in "crisis" will develop such auxiliary hypotheses to save the core tenets of the theory. As seen in the geocentrism example, false hypotheses can survive for hundreds of years before enough "quirks" in the data develop to force some scientists to look elsewhere. However Kuhn observes that scientists will generally not consider abandoning a paradigm or important theory until they are able to replace it with a new paradigm which can better explain the "quirks" of the old paradigm, "...a scientific theory is declared invalid only if an alternative candidate is available to take its place."
“Since the time of Darwin, evolutionists have known about the weaknesses of the theory of evolution and descent with modification. Yet, they have not abandoned it simply because they say, "it's the best theory we've got". Descent, through these "ad hoc" hypotheses, has been forced into an unfalsifiable position, lest it be falsified. “