Paging Gregor Mendel! After years of growing sweet peas in my garden and each year seeing white flowers on all of my plants, I had all but forgotten the geneticist's famous experiments with pea plants and their different flower colors.
This year, though, my pea plants sprouted the most lovely deep purple flowers I'd ever seen. So I went back to my 6th grade mind, and remembered what Mendel learned in the 1790s from the humble garden pea. Wildly simplified, here are two basic principles:
- Traits like flower color are inherited from genetic alleles, one of which is received from each parent plant.
- Purple flowers come on a dominant allele, so if a pea plant has even one purple flower allele, it will grow purple flowers.
What's so fascinating about this? Nothing, really, except that I'm marveling at the realization that for 8 years, the garden pea seeds that I planted just happened to have two recessive alleles (I know this because they grew white flowers). This year, the dominant, purple seeds have come out to play. What are the odds? Less than 50/50, I can tell you that!