In discussions of the relevant importance of genetic and environmental influences on the development of the individual, it's often stated that the genetic and environmental influences interact. An example that is often given is a certain kind of rabbit (usually white), carrying a particular gene for fur color. When the proper allele is present, AND the rabbit is exposed to cold, it will a dark spot on its fur. When the allele is present, the dark spot does not develop without the cold, and when the rabbit has the opposite allele, the spot will not develop even with cold exposure.

This is fine, but when I want to explain genes and environment to people, it has two pedagogical flaws: (1) it's about rabbits (2) it's about a trait people don't really care about

Is there a human example of this phenomenon? That is, a phenotype which requires BOTH a certain genetic background and particular environmental influences in order to be expressed?

  • $\begingroup$ Not answering your question but if you want to read a small introduction in the theory describing how the environment, genetics and other things affect phenotype, you should definitely give a read to this post $\endgroup$ – Remi.b Jul 22 at 20:43
  • $\begingroup$ The rabbit example seems to have at least three pedagogical benefits: (1) it's a simple Mendelian gene (I presume), (2) it's easily and ethically inducible (cold exposure), (3) it's a visible and obvious example of a phenotype: fur color. There are many many human gene-environment interactions but most are studied in the context of disease and are far more complex. $\endgroup$ – Bryan Krause Jul 22 at 21:11
  • $\begingroup$ Could you please give an example? Relevance to human health is exactly what I am looking for. $\endgroup$ – Maringo7 Jul 22 at 21:14
  • 1
    $\begingroup$ @Maringo7 There are so many examples of health related traits that have a non-zero (and non-one) heritability in humans (lung, breast and ovarian cancer, schizophrenia, depression, back pain, sensitivity to common cold, ...) but I can't think of anyone that particularly stand up as a classical example for kids. $\endgroup$ – Remi.b Jul 23 at 20:08
  • $\begingroup$ Maybe glucose-6-phosphate deficiency where hemolytic anemia may be induced by ingesting fava beans? ref $\endgroup$ – user1136 Jul 24 at 0:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.