Our DNA is 99.9% the same as the person next to us — and we're surprisingly similar to a lot of other living things
Lydia Ramsey and Samantha Lee
Apr. 3, 2018, 1:01 PM
Our bodies have 3 billion genetic building blocks, or base pairs, that make us who we are.
And of those 3 billion base pairs, only a tiny amount are unique to us, making us about 99.9% genetically similar to the next human.
A recent TED talk by physicist and entrepreneur Riccardo Sabatini demonstrated that a printed version of your entire genetic code would occupy some 262,000 pages, or 175 large books. Of those pages, just about 500 would be unique to us.
This is because large chunks of our genome perform similar functions across the animal kingdom.
Take a look at how genetically similar we are to everything around us:
Humans are 99.9% similar to the person sitting next to us. The rest of those genes tell us everything from our eye color to whether we're predisposed to certain diseases.
A 2005 study found that chimpanzees — our closest living evolutionary relatives — are 96% genetically similar to humans.
Cats are more like us than you'd think. A 2007 study found that about 90% of the genes in the Abyssinian domestic cat are similar to humans.
When it comes to protein-encoding genes, mice are 85% similar to humans. For non-coding genes, it's only about 50%. The National Human Genome Research Institute attributes this similarity to a shared ancestor about 80 million years ago.
Domesticated cattle share about 80% of their genes with humans, according to a 2009 report in the journal Science.
When it comes to insects' DNA, humans have a bit less in common. For example, fruit flies share 61% of disease-causing genes with humans, which was important when NASA studied the bugs to learn more about what space travel might do to your genes.
And while the egg-laying and feathered body are pretty different from a human's, about 60% of chicken genes have a human gene counterpart.
Even bananas surprisingly still share about 60% of the same DNA as humans!