The Evolution of Human Lifespans

The average human lifespan is 50 years. If you take two of those lifetimes, right, then you have a century. That means that if you have four human lives, then you're back to that point. My wife's grandfather was talking about four 50 year human lives and there are no Europeans basically in the Pacific Northwest. You say 1492, well, you say five or 600 years ago, it just seems like forever ago. 10 or 11 50 year lifespans doesn't seem that long at all.