08/30/2026
THE DNA GAP GETS WIDER
For decades, textbooks and popular science outlets have repeated the claim that humans and chimpanzees are “98 to 99 percent genetically identical.” That number has often been presented as undeniable proof that they share an evolutionary ancestor. But research by Dr. Jeff Tomkins of the Institute for Creation Research is challenging that claim by examining portions of the genomes that simpler comparisons have often excluded.
The famous percentage usually comes from comparing DNA sequences that can be lined up easily and then counting the matching letters within those selected regions. Large insertions, deletions, duplicated sequences, rearrangements, and sections that cannot be aligned may be excluded. If two books were compared only after every unmatched paragraph and missing page had been removed, the resulting similarity would naturally appear much higher than it really was.
In a 2016 study, Tomkins examined 101 publicly available chimpanzee DNA datasets. He randomly selected 25,000 sequences from each one, producing a sample of more than 2.5 million DNA sequences. After trimming low-quality sections and removing cloning-vector contamination, he compared the chimpanzee sequences with the human genome using a sequence-alignment program called BLASTN.
His analysis uncovered an interesting pattern. Sequences produced early in the chimpanzee genome project appeared approximately five percent more human-like than sequences produced later. He suggested this could be connected to human DNA contamination and the way the early chimpanzee genome was assembled using the human genome as a reference framework. Organizing chimpanzee DNA according to the human genome could make the finished assembly appear more human-like from the beginning.
Based on all the datasets, the research placed the overall similarity at no more than approximately 90 percent. Datasets considered less likely to contain human contamination produced an estimate closer to 85 percent.
In 2018, he conducted another comparison using 18,000 long chimpanzee DNA segments called contigs. These came from a chimpanzee genome assembled independently rather than being constructed directly upon the human genome. When compared with the human genome, the sequences produced an average alignment identity of approximately 84 percent. That is far below the familiar claim of 98 to 99 percent.
Newer genome research has made the issue even harder to ignore. A major 2025 study published in Nature used advanced long-read sequencing to produce far more complete ape genomes, including regions that had previously been difficult to sequence and compare.
Professor Richard Buggs, an evolutionary biologist and Professor of Evolutionary Genomics at Queen Mary University of London, examined the data from that study. Buggs is not a young-earth creationist and conducts his research within the conventional evolutionary framework. Yet he calculated that approximately 85.1 percent of human autosomal DNA nucleotides have exact one-to-one matches in the chimpanzee genome.
Buggs does not claim that this disproves evolution. However, his calculation is significant because it comes from a scientist who accepts evolution and is remarkably close to the percentage the ICR research had reported years earlier. Two researchers working from very different starting points arrived in roughly the same range when more of the genomes and their structural differences were included.
This does not mean humans and chimpanzees have no genetic similarities. Both are living creatures that inhabit the same world and perform many of the same basic biological functions. Similar DNA is exactly what we would expect from a common Designer who used effective genetic building blocks throughout His creation. Similarity does not automatically prove common ancestry.
What matters is how that similarity is calculated and what the differences represent. Across genomes containing billions of DNA letters, a difference approaching 15 percent represents hundreds of millions of unmatched, altered, inserted, deleted, or rearranged DNA positions. These differences involve gene regulation, chromosome structure, brain development, speech, upright movement, and many interconnected biological systems.
Evolution must explain how unguided mutations produced all the coordinated genetic changes necessary to transform an ape-like ancestor into a human. It is not enough to emphasize the similarities while minimizing or excluding the differences. Similar building materials do not prove that one structure gradually became another.
Human beings are not simply advanced apes. We were uniquely created in the image of God with the ability to reason, communicate through complex language, recognize moral truth, create art, worship, and know our Creator. As genome sequencing becomes more complete, the supposed genetic gap is not shrinking. It is becoming increasingly difficult to ignore.
