Every zebra’s stripes are unique. Just as no two humans share the same fingerprint, every zebra has its own unique set of curves, quantity, spacing, coloration, or fur density to its stripes.
Except that’s not true at all, is it?
You see, scientists used to think human fingerprints were unique. Then one day, a scientist thought to compare identical twins’ prints, and we learned that fingerprints were a function of one’s DNA. Since identical twins had the same DNA, they shared a set of fingerprints.
This is almost certainly true for zebras as well, who can be born as twins. But that’s okay, we’ll just modify what we said was possible. Add “except for identical twins” to the end, and we’re back in business.
But again, it isn’t true.
Because eventually, we figured out how many variations there were of the DNA elements that determined human fingerprints, and got a good idea of how many different possible fingerprints could exist until we encounter more DNA mutations. Looking at the numbers, there have almost certainly been enough humans throughout the history of our species that two of them who were not identical twins shared a fingerprint. In fact, based on estimates of 64 billion possible fingerprints, the chances are greater than 99.99% that two living people in the United States share a fingerprint at this very moment.
There will probably be two non-twin zebras with the same exact stripes eventually, though over a much longer time span due to lower population density. And of course, that is assuming we don’t cause zebras’ extinction through man-made climate change before the duplicate is born.
So no, human fingerprints are not unique, and neither are zebra stripes. Not in the grand scheme of things, anyways.
But who cares about the grand scheme of things? You probably only care if your fingerprints are unique. And the odds of that are still quite high. You have roughly a 90% chance that your fingerprints will be unique among the current world population.
While we’re at it, who cares about uniqueness among the world population? You don’t care if someone in China wears the exact same outfit to a party as you, just the other guests at the party. In fact, it’s rather novel to imagine someone sharing your outfit on the other side of the world. It’s a 1 in 100 million shot that your fingerprint is duplicated in your neighborhood of 500 people.
Humans should embrace the scientific reality, but cherish the spirit of what that common saying was meant to inspire. You are wholly unique, and your fingerprints are quite unique, too.
And if you’re a zebra, you probably have bigger problems anyways.
