You can pick ANY start point. Humans today are taller, smarter, healthier and live longer.
We dig up human remains from all over the world and from many different times in human history. The average height made them shrimps compared to modern humans.
Height and intelligence are strongly correlated.
Our grandfather's generation, in their prime some 50-75 years ago (for most) were not as tall or as smart by any measure.
So YOU pick the time points.
And humans are not branching into sub-species. People have always mated associatively for height and intelligence and any number of other traits. Human populations are becoming less isolated as social taboos and cheap and easy worldwide travel have led to massive mixing of people.
“Our grandfather’s generation, in their prime some 50-75 years ago (for most) were not as tall or as smart by any measure.”
The average Euro-American is shorter today than 150 yrs ago.
http://research.duke.edu/blog/2010/10/getting-shorter-and-fatter
“Our grandfather’s generation, in their prime some 50-75 years ago (for most) were not as tall or as smart by any measure.”
I have a nice set of dining chairs from around 1825. I can’t sit in them! They’re made for people who were much shorter.