Small changes over time that helps something like a living thing. Like, you know, snakes had legs. Over time things start to change because of their habitat. Say if an animal wasn’t fit for that habitat, they’d like, change over time and adapt to it. It could be like a very, very small change, like the way they breathe or how they breathe. It could be a big change like if they have wings or don’t have wings.
Say a snake found a partner and they have a baby, the baby would get their genes and the baby would pass it to their baby, then loads of snakes, they wouldn’t have legs. And like it doesn’t just have to happen to one snake. It can happen to a few over time.