100 years after Scopes, creationists won’t let go

The death knell for creationism was sounded in the 19^th century, with the recognition of an ancient earth and Darwin’s Origin of Species showing that all life on earth is related by descent. A particular obsession of creationists is the idea that humans and apes descended from a common ancestor. With the advent of protein sequencing and, later, DNA sequencing, the claim was that humans share ca. 99% of their genomic information. 

The creationist community is now greeting with much ballyhoo the recent studies suggesting that the number could be closer to 85%. I’m not sure why 85% sequence identity proves the separate creation hypothesis. At best, it just says that the last common ancestor could have been farther back in time.

But it’s actually more complicated—and for creationists, more awkward—than that. I’ll quote selectively to stay within fair use guidelines, but you can read the whole thing in the link at the bottom.

“At first glance, the recent figures suggesting a greater genetic difference between humans and chimpanzees appear to represent a dramatic revision of earlier estimates—and they are eagerly embraced by opponents of evolution. In creationist circles, the claim that humans and chimpanzees differ by only 1% genetically is now regarded as outdated or disproven.”

*snip*

“But have these newer studies truly debunked the so-called 1% myth? Does a genetic difference of 15% really demand a re-evaluation of human origins? Or is creationism simply engaging in a game of obfuscation—cherry-picking half-truths while omitting crucial context and key information?”

*snip*

“The reported 15% difference refers to the fact that only about 85% of the human and chimpanzee genomes can be aligned base by base—that is, with exact positional correspondence of DNA sequences.

 

“The reason for this discrepancy lies in larger insertions and deletions within the genomes, known as InDels. These are stretches of DNA that have no direct counterpart in the other species’ genome—only gaps can be assigned in their place. Another factor is translocations, in which entire segments of chromosomes have shifted to new positions, disrupting the linear alignment between the two genomes. These changes are the result of chromosomal mutations, which can affect dozens or even thousands of DNA bases at once.

 

“Extended repeats—DNA base sequences (nucleotides) that occur multiple times consecutively in the genome—can also disrupt sequence alignment. These repeats can arise and expand due to errors during DNA replication (known as replication slippage) and mistakes in DNA repair. Mobile genetic elements, such as transposons, also contribute to the accumulation of repetitive sequences.

 

“Transposable elements account for approximately 45% of the human genome, making them extremely common. Way above 90% of these elements have no function (MORAN 2023). They are predominantly found in non-coding regions, where they are less subject to negative selection. As a result, they have accumulated relatively freely over the course of evolution. These elements often affect larger segments of DNA at once, are highly dynamic, and show considerable variation even within a single species. For these reasons, the gaps they cause in sequence alignments are generally not counted as individual nucleotide differences when assessing genetic similarity between species. Since such events usually affect entire blocks of nucleotides, each gap is typically counted as a single difference.

 

“Tandem repeats are generally excluded from genome comparisons because their length is highly variable—even between closely related individuals. For example, every person carries several thousand more differences in the tandem repeat regions of their genome than their parents. While this high variability makes tandem repeats useful for fine-scale analyses of genetic relatedness, they are unsuitable for comparing entire species. Similarly, low-complexity regions (LCRs) are often ignored in genome comparisons. These regions can distort sequence alignments and lead to spurious homologies that do not reflect true evolutionary relationships.

 

“In short, contrary to creationist claims, the established methods for measuring genetic similarity—such as applying special rules for handling gaps—are well-founded and purposeful. These approaches are designed to account for the biological realities of genome structure and evolution. By selectively excluding certain sequence features (like tandem repeats or low-complexity regions), scientists aim to avoid misleading results and ensure that genetic comparisons accurately reflect evolutionary relationships.

The crucial point is this: In those regions where a direct comparison is possible and purposeful, analyses have consistently shown, for decades, a genetic similarity between humans and chimpanzees of 95 to 99%. The exact figure depends on which parts of the genome are being compared—whether coding regions (which produce proteins), introns (non-coding regions within genes), or intergenic regions (the DNA between genes). These values have been consistently confirmed by more recent scientific literature.”

 

But there’s more. 

“One key point creationists usually fail to mention: if you compare the genomes of different primate species and count every base, including those in alignment gaps, not only do the genome-wide differences between humans and chimpanzees increase—but so do the differences within a single species.

 

“According to YOO et al. (2025), chimpanzees exhibit a genetic diversity of 8.8% within their own species. Even more striking: gorilla genomes differ from one another by up to 13.8%—within the same species!

 

“Even worse: If you consider only the gap divergence (without SNV differences), as is the case in the Nature paper, you end up with a 13.3% difference between chimps and humans—which is actually lower than the genetic variability found in gorillas!

 

“Given that such vast diversity can exist within a species, the 15% difference between humans and chimpanzees is not only unsurprising—it is entirely expected, especially considering that their evolutionary lineages diverged roughly 7 million years ago.

 

“In fact, the genetic difference between chimpanzees and gorillas—both of which are considered “apes”—exceeds the 15% difference between humans and chimpanzees.”

You’d struggle to find any evidence that creationist understand the significance of this. Suffice to say, none of these data support a young earth or special creation. I don’t know if it’s ignorance or bad faith, but the creationist circus band keeps on playing.

 

https://pandasthumb.org/archives/2025/07/human_and_chimpanzee.html#more