Natural Selection According to Young Earth Creationists
It seems I’m going to have multiple rants about this talk by the Answers in Genesis Zookeeper, Karina Altman.
This time, I’m interested in her discussion of natural selection. She chooses to use “examples within the frog community”:
- The red-eyed tree frog, which is adapted to living in rainforests
- The desert rain frog, which is adapted to living in deserts
- The hairy frog, which is adapted for self defense.
She concludes:
“Wherever these animals ended up after the flood, whatever genetics allowed them to survive the best in that environment were selected for, and then they kept breeding. Whereas the genetics that did not do well in that environment were eventually lost. So that’s natural selection. It’s a great way that God has used to help his animals thrive throughout the earth.”
I feel that this is clearly implying that the two parents of the frog kind hopped off of the Ark, had a bunch of diverse babies that spread throughout the globe, and the ones that were suited to their environments survived and the rest died, so now we have frogs all over the Earth with different adaptations. That is the AIG story for how kinds diversified throughout the earth, and is commonly applied to other animals like cats and bears.
The problem is that frogs are a very diverse group. I don’t know of a single YEC “expert” that believes frogs are a single kind. Answers in Genesis has an entire paper devoted to just the Frog Kinds, and concludes that there are 140 extant frog kinds. That’s almost 10% of all of the kinds on the Ark! I think Ms. Altman knows that, which is why she uses the term “frog community” instead of “frog kind”. But other than that subtle wording choice, she seems to be very carefully not dispelling the assumption within her audience that frogs all belong to the same kind.
In general, AIG only attributes adaptations that vary within a kind as a result of natural selection. Adaptations shared throughout the entire kind are a part of God’s original design for the kind. So it’s a strange that her examples of natural selection use three frogs from three different kinds. Let’s look at her examples with that in mind.
Red-Eyed Tree Frog
According to the AIG paper, the red-eyed treefrog belongs to the “arboreal tree-frog kind”, also known as the subfamily Phyllomedusinae or the family Phyllomedusidae, depending on the source. As suggested by the name, all species within this family are adapted to living in trees. The adaptations for rainforest life she lists are:
- Suction cup toes.
- Green colouration.
- Laying eggs underneath leaves over pond so that the tadpoles can fall into the water.
This family contains about 129 individual species within this kind, many of which are not well studied. I didn’t do a very through search, but I could not find any species that vary substantially on any of these criteria. They all seem to have the suction cup toes. They are all green when sleeping in camouflage position, though some, like the red-eyed tree frog, have colourful highlights that can be exposed when they are active. They all lay eggs over water so that the tadpoles can fall in when they hatch.
However, they don’t all use leaves, and it’s not always over a pond. Depending on the species, the eggs may be laid in rock crevices, tree roots, tree trunks, or vines, and the water can be a pond, stream, or even just a depression in a tree that traps water. That variation within the kind is what I would expect to be attributed to Natural Selection by AIG. But it would still not match the model created by mainstream scientists.
For example, here is a study of this frog family that compares reproduction in various species. The scientists used DNA sequences to create a tree showing how the frogs diversified over time. They then assessed characteristics of reproduction in the various species. From this they can determine that characteristics that are present in distantly related species were likely present in the ancestral species, and lost in the species that no longer have them, while characteristics that are only present in a closely related group evolved more recently.

But in the YEC model, to determine which characteristics were present in the original individuals on the Ark, you instead must look at which features were most complex, because they don’t believe complexity can arise naturally. Thus, the most complex features would either have been present in the original pair on the Ark, or coded into recessive genes that would show up in their immediate offspring. Natural selection then selected which of those genes were most suitable for the frog’s environment.
Actually, there’s a problematic gap in there, because the Ark landed in Asia. Somehow those offspring had to hop their way to Central/South America, via a land bridge or rafting. Whatever method was used, it seems likely to have taken multiple generations and involve habitats with scarce trees. Why didn’t natural selection select against a sensitive-skinned animal adapted for tree life during the journey? Remember, complex characteristics can be lost, but never regained in the YEC model. By the time they reached South America, I would expect the frogs to be adapted for long distance trekking or salt-water rafting, if any survived at all.
Looking at the leaf frog’s reproduction, the waxy monkey tree frog is would probably be considered the most complex. The frog folds the leaf in half, laying the eggs on the inside. The sticky eggs hold the leaf closed, and they lay extra empty jelly eggs which help to stick the leaf closed, as well as maintaining moisture and diffusing wastes. Compared to that, the red-eyed tree frog’s strategy seems simple, as they just lay a clutch of eggs on a leaf. But in the red-eyed tree frog, like most frogs, the embryos have a “cement gland” which secretes a sticky mucus that allows it to hang motionless from the leaf or egg capsules after it hatches until it’s ready to eat. The waxy monkey tree frog does not have this gland.
Thus, YECs would probably conclude that the original pair on the Ark must have had both leaf-folding and cement gland genes. Secular scientists conclude the ancestral species had the cement gland (which is shared among most frogs) but did not fold leaves (only present in genus Phyllomedusa). So even where YECs accept Natural Selection, their bias that it can only cause “downhill” changes leads to very different models.
Desert Rain Frog
AIG puts the desert rain frog in the “rain frog kind”, otherwise known as the family Brevicipitidae. The characteristics mentioned in the video attributed to Natural Selection are:
- Transparent patch of skin on his stomach that allows him to absorb moisture from the sand.
- Nocturnal.
That’s not a very impressive list. I would have expected her to mention that it spends most of its time burrowed underground in sand dunes, which it accomplishes by basically using its webbed feet to “swim” through the loose sand.
Members of the rain frog family are found in a variety of environments, including forests. Thus, I assume that the desert rain frog’s adaptations to desert life would be specific to that species. However, they all seem to live primarily underground, under leaf litter in a forest, or under moss on trees in Africa. As a result they’re not very well studied. I think there are probably more videos of them squeaking on YouTube than there are scientific papers on these little guys.
All frogs are able to absorb moisture through their skin, so that’s really not an unusual characteristic. Is the translucent patch of skin on the belly of the desert rain frog better at it? It has a lot of blood vessels under it, so probably. But I only found one really old paper that even mentions it, and the author believes it is used to keep the frog cool, not to absorb moisture. I couldn’t find anything about other members of this family having the patch, but I couldn’t find much information at all, so that’s not saying much.
Hairy Frog
Ms. Altman’s most puzzling example is the Hairy frog, which belongs to the “hairy frog kind”. There is only one known species that belongs to this kind. So how can it be used as an example of natural selection? For all she knows they hopped off the Ark looking exactly like they do now!
Conclusion
These were probably the worst examples she could have chosen for Natural Selection from a Young Earth Creationist Perspective.
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