SNP (pronounced “snip”): Single Nucleotide Polymorphism

SNP (pronounced “snip”) stands for Single Nucleotide Polymorphism, a fancy scientific term that means “tiny genetic variation that can determine whether you prefer Coke or Pepsi.”

These little mutations can occur in any of the four nucleotides that make up DNA: adenine (A), cytosine ©, guanine (G), and thymine (T). For instance, an SNP might change an A to a G, turning a perfectly good gene that makes you love Coke into a dud that makes you love Pepsi.

Scientists are fascinated by SNPs because they can help explain a lot of things, like why some people can’t taste cilantro (it’s an SNP in a gene that controls taste buds) or why some people are bald (it’s an SNP in a gene related to hair follicles). They also help researchers pinpoint which genes might be involved in diseases like diabetes or cancer.

But let’s be honest: what you really care about is whether you’re a Coke or Pepsi person. So here’s the deal: there’s an SNP in a gene called TAS2R38 that’s responsible for whether you can taste bitter compounds like phenylthiocarbamide (PTC) or 6-n-propylthiouracil (PROP). If you have one version of the gene, you’ll think PTC tastes horribly bitter and you’ll probably prefer Pepsi. If you have another version, you won’t taste much bitterness and you’ll likely prefer Coke.

Of course, there are plenty of other factors that go into beverage preference, like marketing, upbringing, and sheer stubbornness. But thanks to SNPs, we now have a scientific explanation for why some people are die-hard Coke drinkers and others stubbornly cling to the inferior beverage known as Pepsi.

So the next time you’re at a party and someone tries to get you to switch to the “other” soda, just tell them it’s not your fault—it’s your genes. And then offer them a nice glass of water.