Adult height between ethnic groups often differs significantly. Environmental factors are events that occur before adult height is reached, such as diet, exercise, disease and living conditions.
There are many different ways of looking at it though, and the genetics/evolution route is still a factor.
One of the main theories of evolution is the separation of different species to different areas like Africa, Europe, and Asia. They certain species that migrated towards Asia could have been inherently shorter then the European one for an example.