Human DNA is closest to that of chimpanzees and bonobos, sharing approximately 98.7% of our genetic code. These two great apes are our nearest living relatives, having diverged from a common ancestor somewhere between 6.5 and 9.3 million years ago. Beyond them, the family tree extends outward to gorillas, orangutans, and eventually to surprisingly familiar species like mice and pigs.
Chimpanzees and Bonobos: Our Closest Relatives
Chimpanzees and bonobos are essentially tied as our closest genetic match. Bonobo DNA is about 98.7% identical to human DNA, and the two ape species are themselves 99.6% identical to each other. That 1.2% to 1.3% gap sounds tiny, but the human genome contains roughly three billion base pairs. A difference of just over 1% translates to about 35 million individual points where human and chimp DNA diverge.
Those 35 million differences account for a lot. They influence brain size, language ability, immune function, skeletal structure, and dozens of other traits that separate us from our primate cousins. So while the headline number makes humans and chimps look nearly identical on paper, the specific locations of those differences matter enormously.
Gorillas and Orangutans
After chimpanzees and bonobos, gorillas are next on the list. The DNA difference between humans and gorillas is about 1.6%, making us roughly 98.4% similar. Gorillas split from the human-chimp lineage earlier, which is why the gap is slightly wider. Orangutans, the only Asian great ape, are more distant still, with a 3.1% difference from both humans and the African apes. That puts human-orangutan similarity at around 96.9%.
Neanderthals and Denisovans
If you include extinct species, Neanderthals and Denisovans were genetically closer to us than any living ape. They weren’t just relatives; they interbred with modern humans. Most people of non-African descent carry about 1% to 2% Neanderthal DNA today, while some populations in Oceania carry up to 5% Denisovan ancestry. East Asian populations average around 1.4% Neanderthal ancestry, while West Eurasian populations carry slightly less, around 1.1%.
These aren’t just genetic curiosities. Inherited Neanderthal and Denisovan gene variants influence modern human traits ranging from immune response to skin and hair characteristics. The fact that these genes persisted for tens of thousands of years suggests many of them offered real survival advantages.
Mice Share More Than You’d Expect
Mice are far more distantly related to humans than apes, yet the overlap is still striking. The protein-coding regions of the mouse and human genomes are 85% identical on average, with some individual genes reaching 99% similarity. Of roughly 4,000 genes that have been closely studied, fewer than 10 exist in one species but not the other. This is why mice are the backbone of biomedical research: most of the genetic machinery that drives human disease has a working equivalent in a mouse.
Pigs and Practical Medicine
Pigs don’t match mice in raw genetic similarity, but their organs are remarkably close to ours in size and function. Their physiological metabolism and immune systems resemble human biology closely enough that pigs have become the leading candidate for cross-species organ transplants. Researchers have already transplanted genetically modified pig kidneys and hearts into human patients. The genetic and physiological overlap between pigs and humans is what makes these procedures even theoretically possible.
What About Bananas?
You’ve probably seen the claim that humans share 50% or 60% of their DNA with bananas. The real number is considerably lower, and the claim itself is misleading. The figure traces back to an unpublished comparison done for a Smithsonian educational video, which actually reported 41% similarity, not 50%. That number reflected the average similarity between about 7,000 matching protein sequences, not the full genome. Many human genes have no recognizable counterpart in the banana genome at all, and vice versa. A more rigorous analysis by computational biologists put the figure between 17% and 24%, depending on the method used.
The banana comparison illustrates an important point: “percentage of shared DNA” can mean very different things depending on whether you’re comparing entire genomes, just protein-coding regions, or only the genes that happen to match. When scientists say humans and chimps share 98.8% of their DNA, they’re comparing base pairs across the whole genome. When someone says humans and bananas share 50%, they’re usually comparing a subset of proteins and rounding up. The numbers aren’t calculated the same way, so they can’t be compared directly.
Why Tiny Percentages Matter
It’s tempting to focus on how similar we are to other species, but the real story is in what the differences do. Humans and chimpanzees differ by just over 1%, yet that small fraction encompasses the genetic changes behind upright walking, complex language, extended childhood development, and a brain that is three times larger relative to body size. Many of the most important differences aren’t even in genes themselves but in regulatory regions that control when, where, and how much a gene is active. A gene that builds a protein identically in both species can still behave very differently if it switches on at a different time during development or in a different tissue.
So the answer to “what is human DNA closest to” is straightforward: chimpanzees and bonobos, at about 98.7%. But genetic similarity is a spectrum, and even distant relatives share a surprising amount of biological machinery. The core processes that keep cells alive, like copying DNA, producing energy, and repairing damage, are ancient and broadly conserved across life. What makes each species unique is often less about having different genes and more about using similar genes in different ways.