Have you ever cursed your curls or gotten fed up with stick-straight strands? Most people have hated their hair at one point in their lives, but it has taken thousands of years of evolution to get that way.

“Fur and hair — it’s the same thing,” DNews reports. And if you’ve ever wondered how you hair got its texture, the answer lies in your follicles and proteins. According to video host Trace Dominguez, at a smaller level than the keratin proteins of your hair are amino acids, and the ways those protein building blocks bond to one another influences what your hair looks like: The more evenly distributed the bonds are on the sides of your hair strands, the straighter the hair will be.

Read: Health Conditions That Change Your Hairstyle

Then there’s your hair follicles. For starters, the bigger those are, the thicker your hairs are, Dominguez says. And the more symmetrical, the straighter they are — follicles that aren’t circular will make hairs that bend to one side or the other.

Sometimes our hair is so unmanageable in the morning that we cry and want to resort to drastic measures. Credit: V for Vendetta

These are just some of the ways your biology influences your hairstyle. Hormones also play a role, which is why women sometimes report having thicker hair during pregnancy. And although it’s normal to lose dozens of hairs a day, hormone imbalances caused by issues with your thyroid gland could lead to hair loss.

Other medical problems, like skin conditions, could also affect your hair or cause it to fall out.

Whatever your hair looks like, it is part of you and part of your DNA. Embrace it, because science is always beautiful.

See also:

Weird Home Remedies for Oily Hair and Skin

Head Lice vs. Dandruff