Some of us are short or tall and it all has to do with the climate in which hundreds of generations of their people have spent their lives.
People who have lived in the cold climate of the Arctic need to save every bit of heat their bodies can produce. The more skin they have, the more heat they will lose.
That’s why Eskimos are normally short, with short legs and short arms. They have less body surface than most other humans and can stay warmer in their cold climate.
People who live in very hot places must be able to lose body heat, or they would be too warm. That’s why most Africans tend to be tall, with long arms and long legs.
This gives them a great deal of body surface through which their extra body heat can escape.
its actually diet and other factors. the tallest people in the world are nordic people the average heigh is usually 6 foot 2 in nordic countrys for men. average in the US is like 5 foot 8. africa actually has many short people. few are very tall. not sure what mumbo jumbo you read. reason nordics are the biggest people is because they need a bigger area of mass to absorb more sun and have lighter skin so light can get into there skin for vitamins and so on. a small body is bad for the cold because you get almost no light at all because most freezing places are damp/wet and have very little sunshine. and in ancient times northern europe was full of forests.