 All right, you're ready for this one? Pleotropy. Pleotropy is a situation where you have one gene and somehow that single gene affects many traits. So you've got the eye color trait, the hair color trait, the hair curliness trait, and the tongue rolling trait. And one gene does all of it. How is that... like, whoa. Doesn't that make you wonder, like, what is the protein that's being produced that could actually have such far-reaching consequences? There is a condition called the fragile X syndrome and there's a particular gene on the X chromosome that gets damaged and then it results in low IQ scores as well as large ears, long faces, and big testicles. Really? That's so... like, how does that one gene cause all those different effects? That's an example of pleotropy. The other example, if you love me, you'll get me this chicken. This is a frizzled chicken. What? Dude, I need a frizzled chicken. I mean it. I really want a frizzled chicken. Okay, so frizzled chicken has a frizzled gene. Really? I want a frizzled gene. And the frizzled gene gives it the frizzled feathers. Oh, I really want a frizzled chicken. But frizzled gene also gives it fewer eggs, higher metabolism, and greater digestive capacity. Right? Basically, fewer eggs. Maybe we don't want a frizzled chicken because if it's eating more and producing fewer eggs, that seems like kind of a bad combination. I think I want it anyway. That thing is cute. I wonder how big it is. And I wonder if I can name it like frizzy. Frizzy the frizzled chicken. And we can go on the Magic School Bus together. Okay, the next thing I'm going to talk about, I'll go back to blood types. I can talk about the frizzled chicken all day, obviously, but I'll go back to blood types. And we will revisit a different situation with bloods type being adventures called epistasis.