Hi everybody, this is Gadsad. On many previous occasions, I've explained the concept of costly signaling,

also known as Zahavian signaling, also known as the handicap principle. You can read this book by Emots and Abyshag Zahaviavi Zahavi signalling refers to a type of costly signaling.

Let me explain to you what that is.

And as you can see here, it shows the peacock's tail.

The idea basically is that some traits could not have evolved because they confer a survival advantage.

If anything, they reduce your survivability. So the peacock's tail is very burdensome.

It's hard to take flight from predators. It makes you conspicuous. And so, if anything, you should be less likely

to evolve that trait if it were simply for survival. But when we know through sexual selection,

there are traits that evolve because they offer a reproductive advantage.

But then why should it be so burdensome?

And so the concept of costly signaling means, in evolutionary biology,

means that a trait, in order for it to be an honest signal,

it has to be costly to the one who is emitting

the signal because otherwise, anybody could imitate it and do so in a duplicitous manner.

So if a female is trying to identify the really top contenders from the pretenders,

if the signal is one that everybody can copy,

then the female is stuck in a situation where she can't discriminate

between the different males.

But if having that particular trait or a particular behavior

is so costly that that itself serves as an

honest signal of my quality, then this is known as a costly signal. And so again, this is what

Zahavi signaling is because Zahavi studied, he was an Israeli ornithologist who studied

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