Why would the young males in the baboon tribe from a study in "almost Human" by Shirley Strum sacrifice their lives while crossing the Savannah defending the tribe?

 This was what really amazed me about this study.

The young males (if they survived battle with lions and didn't get defeated or eaten or mortally wounded then could mate with some of the beta Females as a reward for fighting off the lions as the baboon tribe moved across the Savannah from their safe tree to another tree somewhere else.

Also, if they could mate with beta Females they might also move of the chain of command to the Alpha Level and then have the chance of fighting the present Alpha Leader for leader of the Tribe of Baboons.

So, as I read this I thought "Wow! How similar these Baboon tribes are to humans in the pecking order of how you move up the ladder to better and better things in your life.

If you can survive the attacks as a young male of various kinds often you can move up the ladder to success of various kinds in life where your life is better. You are safer and you get to mate with one or more beta Females or even Alpha Females and then you might even progress to be the Alpha Male of your Tribe of Baboons.

I was pretty astounded at the time realizing just how similar to humans these baboon tribes are to the early ways that men and women and children survived around the world.

And I had more respect for both baboons and for humans in general after surviving all of this millions of years down through prerecorded history.

And the most important thing here is actually sort of this in an oblique way:

"Those who don't learn from history are doomed to repeat it.