How to Think About Any “Transitional Fossil”: Evidence for Evolution (Part 10)

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Are fossils “rock-solid” evidence for evolution? Museums and textbooks might say so, but here’s how you can apply the 7 Checks of Critical Thinking to reach a biblical, logical conclusion about any “transitional fossil” claim.

When was the last time you heard that a “transitional fossil” reveals a snapshot of earth’s evolutionary past? Maybe while scanning a textbook or surfing the web, you heard Tiktaalik represents an evolutionary intermediate between fish and land animals, Archaeopteryx represents an intermediate between dinosaurs and birds,1 or Lucy represents an intermediate between ape-like ancestors and humans. You can learn much more about these and other specific fossils elsewhere. Meanwhile, let’s see how to think through any transitional fossil claim using the 7 Checks of Critical Thinking.

1. Check Scripture2

Genesis indicates God designed creatures to reproduce according to their kinds, even if there’s impressive variation within those kinds. So biblically, we wouldn’t interpret a fossil as being half-way between two kinds. (See Check 6 below for biblical interpretations of fossils instead.)

2. Check the Challenge

Given that fossils are dead things, the fossil record is a chronicle of death and suffering. Biblically, death and suffering resulted from Adam’s sin (e.g., Romans 5:12 and 8:22). Saying that fossils represent an evolutionary process of death and suffering leading up to humans, therefore, challenges clear teachings from Scripture. So, let’s move onto Check 3.

3. Check the Source

Where do claims about transitional fossils come from? Such claims can’t stem from sources which start with God’s Word as their absolute authority, because the term transitional already assumes evolution between kinds is happening.

4. Check the Definitions

On that note, when defining keywords in fossil discussions, some researchers recommend using the term intermediate form rather than transitional fossil, to avoid evolutionary implications. But it’s still worthwhile clarifying what type of intermediate we’re talking about. Does a fossil look like an intermediate between two kinds, was it found in rock layers between two kinds, or both? Does its whole body appear to be an intermediate between two kinds; does it have one feature which looks like it belongs to another kind, or does it have several features which resemble intermediates between two kinds? Clarifying what seems to be “intermediate” will help you describe the observational science later in Check 6.

5. Check for Propaganda

Why might transitional fossil claims sound convincing? Evolutionary claims about Tiktaalik, Archaeopteryx, and Lucy may seem persuasive because they’re repeated so often from different sources. But repetition cannot make a message true. Neither can eloquence, popularity, or illustrations depicting what artists imagine fossils’ living counterparts looked like. Such illustrations often have built-in evolutionary assumptions, which you can identify with Check 6.

6. Check the Interpretations

As usual, we can separate fact from interpretation by breaking Check 6 into several sub-steps:

Identify the Observational Science

For any transitional fossil message, what are the facts we can observe in the present? The facts are the fossils themselves, and the rocks in which they were found. Interestingly, those rocks don’t always give dates that match a straightforward evolutionary scenario, even using evolutionary dating methods. (More on that in a moment.)

Identify the Historical Science

When it comes to fossils, observational science doesn’t always have much to go on—especially if the skeletons aren’t complete. Ideas about what missing bones might have looked like, how those bones affected the animals’ body plans, and how the soft tissue functioned and fitted everything together are all interpretations from historical science. Presenting these interpretations as reality in textbooks and museums is just propaganda—an attempt to make evolutionary stories seem persuasive by appealing to aesthetics rather than fact.

Also, notice we can’t directly observe function from fossils. We don’t know exactly how creatures used some of their now-fossilized features. For instance, coelacanth fossils have lobed fins that some evolutionists thought represented precursor limbs—until live coelacanths were observed using those fins for swimming.

Finally, remember the very label “transitional fossil” (and any story about the past that goes along with it) is an interpretation based on evolutionary assumptions, not a definite fact.

Identify the Assumptions

What are some of those assumptions? Generally, “transitional fossil” stories assume that earth is millions of years old and that evolution can change one kind of creature into another. (For more about the problems with these assumptions, check out articles on information theory, life’s origins, mutation, and natural selection.)

Identify an Alternative Explanation

What’s a different, biblical explanation for intermediate-looking fossils? Because Genesis indicates God created creatures “according to their kinds,” we can predict that any transitional fossil claim probably involves one of three scenarios:

  • Scenario 1: The fossil represents a specimen from either one kind or another kind—not something in-between. For example, observational science typically reveals that “ape-man” fossils are fully ape or fully human, even if movies and textbooks try to represent ancient humans as more ape-like (or ancient apes as more human-like) than the bones alone indicate. Likewise, other articles explain how Archaeopteryx was an interesting but unequivocal bird, and Tiktaalik was simply a fish.
  • Scenario 2: The fossil is made of bones from different specimens belonging to separate kinds. This is especially possible if the bones were found in different locations or in the case of forgeries. For instance, the infamous “Piltdown man” skull was forged from human and orangutan bones.
  • Scenario 3: The fossil represents another, separate kind, with a mosaic of features resembling those of other organisms and reflecting creatures’ shared Designer. Platypuses, for example, have characteristics spanning multiple animal groups.

Identify the Rest of the Story

With these three possibilities in mind, you can look closer at observational science to see if there’s more to “transitional fossil” stories. For instance, a biblical explanation makes much more sense of the abrupt “appearances” of many living things (and their distinguishing features) in the fossil record. Furthermore, evolutionary dates for rock layers surrounding fossils don’t always support a straightforward evolutionary explanation.

For example, Tiktaalik is considered younger than fossil footprints of a four-footed animal, which supposedly came after Tiktaalik. Evolutionists could speculate that Tiktaalik’s ancestors were “transitional forms.” But the point is, observational science doesn’t necessarily match what straightforward evolutionary scenarios predict. That’s why, although textbooks may still show linear diagrams of transitional fossil series, modern evolutionists usually believe intermediate forms follow branching patterns rather than linear sequences—including in the famous horse and whale fossil series.

Even for the most supposedly straight-forward sequences, “transitional features” don’t always develop as smoothly as textbooks suggest. My own first-year biology textbook declared, “the fossil record shows that the unique features of mammalian jaws and teeth evolved gradually over time, in a series of steps,” adding, “If all the known fossils in this sequence were arranged by shape and placed side by side, their features would blend smoothly from one group to the next.”3 Actually, geologist John Woodmoreappe did arrange those fossils by evolutionary date back in 2001, concluding,

One of the most striking findings uncovered by this analysis is that the majority of anatomical traits (the ones actually used by evolutionists in the construction of their cladograms) do not show a unidirectional progression towards the mammalian condition!”4 (Emphasis in original.)

Instead, many mammal-like traits disappeared and reappeared throughout the sequence, and large evolutionary gaps occurred in the few traits that did progress linearly. Crossing large gaps would require gaining functional new genetic information. So, other useful questions include, “What else would have had to happen for this fossilized creature to transform into another kind? And does observational science support such transformations as being possible?”

7. Check the Logic

What final lines of faulty logic should we watch for in transitional fossil claims? One example is circular reasoning in arguments that transitional fossils are evidence of evolution, given that the word transitional assumes evolution happens. Even saying, “evolution predicts intermediate forms, and intermediate forms exist, so evolution must be true,” uses the affirming the consequent fallacy.

Same Fossils, Different Lens

Ultimately, the same fossils may be claimed as evidence for evolution or a biblical worldview, depending which worldview lens we use to interpret those fossils. By beginning with a biblical worldview and applying a little critical thinking to any transitional fossil claim, we can discover these fossils fall far short of “proving” evolution. Rather, “transitional fossils” often cause problems for evolution yet are consistent with biblical interpretations. In the end, a biblical worldview provides a rock-solid foundation from which to examine any fossil.


  1. Archeopteryx’s exact position within the supposed dinosaur-bird transition has been up for debate among modern evolutionists. (E.g. see Federico L. Agnolin et al., "Paravian phylogeny and the dinosaur-bird transition: an overview." Frontiers in Earth Science 6 (2019): 252).
  2. Is it circular reasoning for Christians to compare messages against Scripture? No: to find out why not, see Critical Thinking Scan Episodes 36, 37, and the associated resources.
  3. Jane Reece et al., Campbell Biology, Canadian ed. (Upper Saddle River, NJ: Pearson, 2014), 548.
  4. John Woodmorappe, “Mammal-like Reptiles: Major Trait Reversals and Discontinuities,” Journal of Creation, 15, no 1 (April 2001): 44–52,


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