How Much DNA Do We Share With Chimpanzees? The Real Figure

Where does the 98.8 percent figure come from?

A genome is a long string of four chemical “letters” (A, C, G and T). In 2005, the Chimpanzee Sequencing and Analysis Consortium published the first draft of the chimpanzee genome and compared it with the human genome. In the stretches that could be aligned letter by letter, about 1.2 percent of the letters were different, roughly 35 million single-letter changes in all.

That is where the familiar “98 to 99 percent” comes from. It is a real and useful measure, but it only counts one kind of difference: places where one letter has been swapped for another in DNA that otherwise matches.

What happens when insertions and deletions are counted?

Genomes also change when pieces of DNA are added (insertions), lost (deletions) or copied (duplications). The 2005 comparison found around 5 million insertion and deletion events between the two species. Some are a single letter long, others thousands of letters long. Counting the extra DNA they involve raises the overall difference to roughly 4 percent by the measures used at the time.

Newer, complete gap-free ape genomes, published in 2025, include the hard-to-read repetitive regions that early drafts skipped. When every stretch that cannot be lined up between the species is counted, the share of differing sequence rises well above 10 percent. In other words, there is no single “true” percentage. The answer depends on what you count.

What does a small DNA difference mean?

Even 1.2 percent of a genome of about 3 billion letters is tens of millions of changes. Most of them sit in DNA that does not code for proteins and have little or no effect. A small number fall in genes or in the switches that control when and where genes turn on, and these can have large effects on the brain, the skeleton and the immune system.

Chimpanzee and human proteins are very similar: a typical protein differs by only one or two building blocks (amino acids), and about 29 percent of proteins are identical. Much of what makes us different seems to come from how genes are regulated rather than from the genes themselves.

There is also a visible difference in packaging. Chimpanzees have 24 pairs of chromosomes and humans 23, because two ancestral ape chromosomes fused to form human chromosome 2.

Which genes make the difference?

Scientists are still working out which changes matter most. One well-studied example is FOXP2, a gene involved in the control of speech and language. The human version differs from the chimpanzee version by two amino acids, changes that seem to have spread in our lineage, although FOXP2 is only one small part of the story.

Gene families also grow and shrink. A 2006 study estimated that about 6 percent of human and chimpanzee genes do not have a one-to-one match in the other species, because genes have been duplicated or lost since the two lineages split. Several human-specific gene copies are active in the developing brain.

Are bonobos just as close?

Yes. The bonobo and the chimpanzee are sister species in the genus Pan. Their lineages separated roughly 1 to 2 million years ago, long after the Pan lineage split from ours, so humans are equally related to both. The bonobo genome, published in 2012, showed that about 1.6 percent of the human genome is closer to the bonobo and about 1.7 percent closer to the chimpanzee, simply because of how ancestral gene variants were sorted among the three species.

Chimpanzees and bonobos differ from each other by only about 0.4 percent in single letters, which is why they look so alike; see chimpanzee vs bonobo.

How do other apes compare?

These figures follow the same pattern as the family tree of the great apes. Gorillas branched off before the human and chimpanzee lines split, and orangutans earlier still. That is also why chimpanzees count as apes, not monkeys; see Are chimpanzees monkeys?

Myth: we share 60 percent of our DNA with bananas

The banana claim is a popular but misleading comparison. It comes from estimates that a large share of human genes have a recognizable counterpart, a related gene doing a similar basic job, in plants such as the banana. It does not mean that 60 percent of our DNA letters match a banana’s. The same logic applies to claims about fruit flies, mice and other organisms.

Myth: humans evolved from chimpanzees

High DNA similarity does not mean that we descended from chimpanzees. Humans and chimpanzees share a common ancestor that lived roughly 6 to 8 million years ago. Since then both lineages have changed, so modern chimpanzees are just as “evolved” as we are, along a different path.