Boundary-Crossing Doppelgängers: A Fallacy in the Flood Boundary Debate

Chad Arment (2023)

A baraminic lineage that survived the Flood on the Ark could potentially be found represented by fossils on both sides of the Flood/post-Flood boundary. Technically, it is even possible that multiple genera and species within the baraminic lineage could be found on both sides of the boundary. But what if the very same multiple genera and species are found on both sides? If it is an unclean terrestrial kind, the traditional understanding of Scripture is that only one pair was included on the Ark. So while the same baraminic lineage could be found in Flood and post-Flood deposits, we should not find the very same multiple genera and species on both sides of the Flood boundary.

This is a distinct problem for all Upper Cenozoic Flood Boundary (UCFB) proponents, whether they consider the boundary to be Pliocene-Pleistocene or Pleistocene-Holocene (or some mixture of the two). There are far too many boundary-crossing genera and species within the same terrestrial baraminic lineages. Hand-waving and saying “It’s not really a problem,” (as I heard one profess at the recent ICC) does not actually remove what is a very significant problem.

The issue is most notable with a well-studied baraminic lineage like the Felidae. There are three subfamilies to note: the extinct Machairodontinae, the Pantherinae, and the Felinae. Within the machairodonts (‘saber-tooth cats’), Homotherium, Dinofelis, Metailurus, and Megantereon all cross the Pliocene-Pleistocene boundary. Within the Pantherinae, Panthera crosses both the Pliocene-Pleistocene and Pleistocene-Holocene boundaries. Digging a bit further down, Panthera atrox (the American lion), Panthera leo (lion), Panthera onca (jaguar), Panthera pardus (leopard), Panthera tigris (tiger), and Panthera uncia (snow leopard) all crossed the Pleistocene-Holocene boundary. Within the Felinae, Acinonyx, Felis, Lynx, and Puma cross both the Pliocene-Pleistocene and Pleistocene-Holocene boundaries. The extinct feline Sivapanthera also crossed the Pliocene-Pleistocene boundary. Panthera, of course, is known to have hybridized with members of the Felinae, bringing those two subfamilies together. It is reasonable to assume that all three subfamilies are part of a single baraminic lineage, but even if the machairodonts were separate, the problem does not diminish.

This data gives us 10 genera within the Felidae that crossed the Pliocene-Pleistocene boundary, and 5 genera that crossed the Pleistocene-Holocene boundary. Within Panthera, 6 species crossed the Pleistocene-Holocene boundary.

This clearly rules out the idea [Model 2] that multiple pairs within a single unclean created kind were on the Ark, as Lightner (2021) suggested. (See also Arment (2022).) No reasonable interpretation of Genesis allows for 20+ felines on the Ark. Noah was not a ‘cat person.’

But could all these felines have suddenly appeared from a single Ark pair, ‘re-evolving’ into the same genera and species from before the Flood? That bit of science fantasy [Model 3] has been subtly pushed by some UCFB proponents. The implication appears to be that a baraminic lineage simply has to turn on or off a few genes and ‘poof!’ all the same genera and species reappear as post-Flood doppelgängers. Or at least the same genera and species that are found fossilized in the uppermost Flood layers . . . explain that one to me, please. All those felines found in lower layers? Still R.I.P.

This is essentially the result of an a priori fallacy. The UCFB proponent starts off with their Flood boundary concept, sees that there is a boundary-crossing problem, and tries to rationalize it with a poor understanding of genetics and the fossil record. What are the problems with this idea?

The wide range of morphological differences between saber-tooth felines, tigers, cheetahs, lynx, and Felis catus are not simply the result of increasing or decreasing overall size. There are specific changes in dentition, skull formation, postcranial skeleton, and physiology that are adapted to specific environments and behavior. With a Lower Cenozoic Flood Boundary [Model 1], there is distinctive and logical progression of morphological changes in genera and species through biostratigraphic layers tracing the Felidae back to the oldest known true cat, Proailurus. A UCFB not only randomizes those changes (which would technically all be found in the same Flood deposit, signifying a single period of time), it provides no logical recourse to bring all of those morphotypes back to reality. There is no indication of any such morphological transition in the Pleistocene or early Holocene despite plenty of fossil and subfossil material. All of those genera just ‘magically’ appear. That’s not the result of a miracle. That’s the result of sloppy argumentation.

The traditional Lower Cenozoic Flood Boundary Models continue to provide the most appropriate interpretation for the paleontological evidence of the global Flood.


Arment, C. 2022. Ruminating on created kinds and Ark kinds. Answers Research Journal 15: 391-404.

Lightner, J. K. 2021. Created kinds vs Ark kinds—implications for creation research. Journal of Creation 35(3): 109-115.