This is an article explaining about variation in a population in general, using height as a specific example. The article is designed to help students and teachers think about the nature of various determinants underlying biological variation. Variation in height is easily observed and measured by learners, and quantifying height observations over time is a rich context for all ages to make key mathematics and science connections. "Fast Plants, rapid cycling Brassica rapa are ideally suited for getting a handle on variation."