We have always lived

I sat with someone i knew for quite some time, we talk about anything that has an interesting topic that comes to mind..
We sat the other day discussing an interesting tale about humans living older than before or it was so told.. Curious as i was i asked ;" What do you mean ? " He smiled and said;" We live as old as we always have, being free or chained is really the difference nothing else " I wondered a while and i really couldnt understand. So i said;" the average was lower once" and he replied ;;" Indeed it was "

He sat and said;" Think, its common sense" And so i did, and i said;" oooh "
"Those who survived their infant, grew as any other. Those who did not, became a number.. If we can give offspring almost 13 times a year, it means our chances were low from mother nature.. But those who lived became as old as any other, there is really no mystery to that tale.. "

And we continued to talk as we did another day