Does an increase in heart speed heighten your senses?

Answer 1

The two changes are associated, but I think what's happening is that they both

have the same root cause.

Historically, it's the release of adrenaline, and other things that immediately begin

sloshing around in all those places at the bottom of the brain with names I can

never remember, the instant the big saber-tooth that I've been stalking for a week

decides it's had enough, and turns around and starts coming at me full-speed.

Those chemicals blast through my arteries, my senses become sharper, and my

heart starts pounding ... exactly what I need, whether I decide to stand my ground

and fight the cat, or turn around and do a Usain Bolt in the other direction.

Did these situations CAUSE the chemistry in my my ancestors' bodies to change ?

Absolutely not. The cause and course of evolution were much less subtle than that.

Over the countless millennia in the caves, some people were born with bodies

that could produce natural stimulants in seconds, and others weren't. All of

these people needed to eat, and they all went out to stalk the cats in the grass.

Most of the cats turned on most of the hunters. Some of the hunters got away

and lived to hunt another day, and some wound up as tasty morsels for the cats.

The hunters that became cat food didn't have as many children as the hunters

that got away, and since children are often born with characteristics that resemble

those of their parents, the population eventually swung in favor of the line of

people who carried their own performance-enhancing drugs around with them.

I never took a Biology course, but that's the way I understand it.