Many people think genetics works like this.
While it is certainly a wonderful joke, this isn’t exactly what happens. Indeed, Dawkins devotes a few pages on this in The Greatest Show on Earth. Mendel actually discovered something contrary to the “blending of traits.” As Dawkins states, if traits were indeed a mix of the traits of each parent, we would see children with a combination of the traits of both parents, grandchildren would receive traits from all four grandparents, and, very quickly, diversity would decrease to a homogeneous blend. Dawkins uses the “mixing paint” metaphor. If you mix red paint and blue paint to get purple paint, no quantity of mixing will ever yield the original red or blue paint again.
So what, exactly, are the Mendelian laws?
The Law of Segregation states that when gametes are formed, the specific traits previously inherited from the parents are separate entities and are segregated from one another with only one of the two being inherited by offspring from each parent.
The Law of Independent Assortment states that traits from the same parent are not linked to one another. This means that the offspring can inherit a trait from one parent and a different trait from the other parent. While many genes are technically not “dominant” or “recessive,” traits can be. Most often, genes are coexpressed in differing cell populations or, sometimes, in the same cell. The traits resulting from one specific allele can appear to mask the traits of the other allele.
This is a point which needs further clarification in the very near future.