[negom (OP)]

There are correlations between differences in height and lines of gender, ethnicity and generations. To what extent are differences in height linked to long term structural differences in nutrition? Does the fact that over centuries, men's privileged position meant that they received more food than women contribute to the fact that women are on average shorter? And is the reason why children are often taller than their parents, that their generation grew up wealthier on average?

[syhprum]

It is believed that the more than normal height height of Netherlanders is due to the early introduction of improved agriculture. 

[evan_au]

Access to nutritious food, good health care and healthy exercise all contribute to height.
- Or we could reverse it, and say malnutrition, disease, and neglect stunt growth

But in children growing up in the same environment, boys are slightly taller (by 9%) and more massive (by 16%) than girls.
- I do not believe that this is due to malnutrition and disease, although there probably is a gender difference in the amount of exercise that children are expected to perform.
- The innate differences reflect a mild degree of sexual dimorphism in humans

See: https://en.wikipedia.org/wiki/Sexual_dimorphism#Humans
 

[alancalverd]

It would be odd if humans were the only mammals that did not exhibit sexual dimorphism, said the flat-chested, bald, bearded lady. You wouldn't argue with her, at 6'6" and 180 lb.

On a couple of visits to Belarus I've been impressed by the considerable difference between people I've met. Almost all the men were tall and dark and the women short and blonde. Not just hair color, which may well be artificial, but skin tone and eye color too. It's been a small sample, mostly one factory and a few restaurants, but oddly striking. I wonder if anyone else has noticed, or if my sampling was biased by some excellent vodka? 

[vhfpmr]

But in children growing up in the same environment, boys are slightly taller (by 9%) and more massive (by 16%) than girls

Raising a Chihuahua and a Great Dane in the same home won't make them the same size, but that doesn't prove that selective breeding didn't create the size difference in the first place.

[evan_au]

Raising a Chihuahua and a Great Dane in the same home won't make them the same size, but that doesn't prove that selective breeding didn't create the size difference in the first place.

Selective breeding means you breed the smallest dogs with other small dogs (and big dogs with other big dogs).

Using selective breeding to explain sexual dimorphism implies that all the males were bred with other males, and all the females were bred with other females.
- That doesn't make much sense to me (at least, in mammals)...

[CliveG]

I look at my two sons (each with a different mother). One is short and the other smaller than me or his uncle/mother. After our divorce, the diet of the two was nutritionally poor. Irregular meals. The younger one ate only MacDonalds and took off all the trimmings.

I look at farmers in South African and New Zealand who have a big healthy breakfast for the days work. They are tall and powerfully built. My Dad's brother had hands with fingers like bananas and could toss two sacks simultaneously (one in each hand) onto the truck.

[vhfpmr]

Raising a Chihuahua and a Great Dane in the same home won't make them the same size, but that doesn't prove that selective breeding didn't create the size difference in the first place.

Selective breeding means you breed the smallest dogs with other small dogs (and big dogs with other big dogs).

Using selective breeding to explain sexual dimorphism implies that all the males were bred with other males, and all the females were bred with other females.
- That doesn't make much sense to me (at least, in mammals)...

Perhaps I should have used the term selection by environmental factors rather than selective breeding.

[Outcast]

All the 1000 lb. + marlin in the oceans are female. The males seldom exceed 400 lbs.