If you want split-second speed, you need fast-twitch muscle fibers. Fast-twitch muscle fibers come from the protein alpha-actinin-3, which is created thanks to the ACTN3 gene. One or both of these genes can be defective in people – in fact, eighteen percent of us have inherited two defective copies, which makes it harder to build muscle.
A number of elite sprinters and super-strong powerlifters, on the other hand, have two working versions of the gene, and thus develop fast-twitch muscle fibers at a higher rate. Don’t be fooled, though – there’s still plenty of training involved.
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.
Eye Color Based on Region of the World
Eye color is the kind of thing that high school students use to learn about genetics, so you'd think it's one of the simpler elements. On the other hand, it turns out the science behind eye color is pretty fascinating.
Your eye color is a way to tell people what area of the world you're from. It goes even further than just “dark,” or “blue,” since the specific shade can tie you to East Asia, Africa, the Middle East, and or all over the world. Certain genetic variants pop up from each of the areas. It's easiest to do this with the darker shades of iris.
The Gene That Protects Against Malaria
Malaria is incredibly dangerous, but there are some people that are protected against it thanks to their genes. Blood disorders are never the best thing for people, but one gene-caused condition at least does a good thing.
Those that have one sickle gene and one normal hemoglobin gene are more protected against malaria. While that does mean they're carriers for sickle-cell disease, it also means they're safer in some ways. This reveal could help develop malaria treatments in the future, potentially saving millions of lives.
When you're out drinking with your friends, do you start to get a rosy hue after just one glass? Your genetics is to blame. Specifically, a mutation on the ALDH2 gene.
A certain defect interferes with the liver to convert an alcohol byproduct – acetaldehyde – into its next form. Instead, the acetaldehyde builds up in the blood and causes the capillaries to expand, increasing the blood flow and making you blush. That might not seem too bad, but acetaldehyde is a carcinogen, so tread with caution. One possible way to avoid the downsides is to reduce drinking.