In any moderate group of people, there’s a pretty good chance that someone is lactose intolerant. Lactose intolerance is found all over since it’s an evolutionary trait. Before we cultivated animal milk to drink we were weaned off after a year or two. It’s especially common in East Asia and China.
Of course, the trait doesn’t mean that every child someone with LI has will also have it – there are plenty of siblings who don’t share it. For some reason, people from northern Europe have much lower LI rates than the rest of the world.
Those Simple Little Dots
It's hard to argue that freckles aren't at least a little cute, but you may be surprised to learn that they, too, are the result of mutations. Partially, anyway. It has to do with melanocytes — the cells in the skin that make pigment.
When exposed to UV light, they produce melanin, which makes skin darker to protect us. When the gene MC1R isn't working properly, freckles are created instead of a tan after time in the sun. Another version of this gene is responsible for red hair, which is why it's so common for those with red hair to have plenty of freckles, too.
A Split in the Jaw
A cleft chin is actually a slight mishap during development, but seeing as how it doesn't present any problems, you'd likely never know. Not all cleft chins are exactly the same, but they all happen the same way – when the two halves of the jaw bone, or the muscle, don't fuse properly.
Men are more frequently cleft-chinned than women at an almost two-to-one ratio due to the jaw sizes. Cleft chins are common but not a dominant trait. Even if two parents have perfectly round chins, there's still a chance a child could have a cleft chin.
Your Genetics Give You a Sweet Tooth
Thanks to 23andMe, the company that allowed you to look into your family genetics, people have discovered lots of things about themselves. One of those things is Europeans have a huge preference for sweet foods compared to the rest of the world.
There's a clear reason for this — since sugar has lots of calories, and during most of the history of the world, that was something you needed as much as possible. There's still plenty of personal preference at work here, but Europeans have a much higher chance of loving their sweet treats.
What if You Love Salty Foods?
It turns out your genetics have a lot to do with what kind of foods you like to eat. People of East Asian descent have a tendency to enjoy salty foods a lot more than the rest of the world.
While it's fully possible this has to do with the genetics of a person (tongues, taste buds, etc), it's also just as possible that the kind of food you eat while you're a child informs what kind of food you like. It's the classic nature versus nurture debate, but it's clear that the part of the world your genetics hail from at least does part of it.