[rotorwrench]

The Human genome is affected by a multitude of factors. The average male height has changed significantly in the western world over just the last two or three generations. The US is a melting pot of peoples from all over the planet including earlier native humans that moved here at the end of the last ice age. My Pops family were primarily made up of Germanic peoples. Some were very tall,up to 6'6" and some were shorter down to 5'8" or so. Pop was 6'1" and my Mom was 5'2" so I ended up 5'10".

The food we eat and our relative health can have an affect on the Genome as well. Folks back in the beginning of the 20th century had an average height of 5'6" and it's now around 5'10". One problem with the modern era is that our average weight has also gone up.