Whenever I lecture about quantitative genetics, I always talk
about height in humans as an example of a trait influenced by
the expression of many genes. Since I teach at the University of
Connecticut, I often show the pair of photographs in this
article from Genetice1, because (a) it shows a nice bell curve
of heights and (b) it allows me to show how the environment can
influence the expression of quantitative traits.2 I talk about
Nilsson-Ehle's results on kernel color in wheat as an example of
how multiple genes3 may influence the expression of a phenotype.
Now thanks to recent work described in Nature Genetics I can
give students a best guess as to how many genes influence height
variation in humans. The answer? Genome-wide association studies
have identified many variants affecting susceptibility to
disease. Now, three studies use this approach to study adult
height variation in a combined sample size of ~63,000
individuals and report a total of 54 validated variants
influencing this trait.4,5,6,7 Height