Question

Suppose you are telling your roommate that you learned in biology class that within any given human population, height is highly heritable. Your roommate, who is studying nutrition, says, "That doesn't make sense, because just a few centuries ago most people were shorter than they are now, clearly because of diet. If most variation in human height is due to genes, how could diet make such a big difference?" Your roommate is obviously correct that poor diet can dramatically affect height. How do you explain this apparent paradox to your roommate?

Answer 1

Height is influenced by both genetic and environmental factors. Environmental influences, like nutrition, can significantly affect whether an individual reaches their full genetic potential for height. This illustrates the complex interaction between heritability and environmental factors in determining traits like height.

Step-by-step explanation:

When we say that height is highly heritable within a human population, we are referring to the genetic potential for height that individuals inherit from their parents. However, environmental factors such as nutrition play a crucial role in determining whether people can reach their full genetic height potential.

Genes and environment interact in complex ways, often described as a reciprocal relationship. While genes set the boundaries for our potential development, availability of resources such as food, alongside other environmental factors, affects how much of this potential is realized.