Sexy son hypothesis

The sexy son hypothesis is a theory about how some animals have evolved to attract mates. Imagine you're a bird, and you're looking for a mate. You want the best possible mate with the best genes, so that your babies will be strong and healthy.

Now, let's say there are two male birds. One is really good looking and the other is just okay. The good looking bird has bright feathers and sings a beautiful song, while the okay bird is more plain and doesn't sing as well.

The female bird would be more likely to mate with the good looking bird because he has better genes. She wants her babies to have bright feathers and a beautiful singing voice too. So, even though the okay bird might be a better dad or provider, the female bird will choose the good looking bird because his genes are more attractive to her.

This is called the sexy son hypothesis because the female bird is choosing the bird that will give her sons with the best genes. And those sons will also be attractive to future mates, continuing the cycle.