How can two parents without hitchhikers thumb have a child who does have hitchhikers thumb

Question

juicstice · Answer

most likely the parent's parents had hitchhikers thumb or at least one of them did

anonymous · Answer

@ntruex123 @Juicstice Okay, to really understand this question we you need the background knowledge. Hitchhiker's thumb (TB) was a trait that for many years was considered to be a dominant/recessive trait. Just like Mendel's peas. So, if was often said that if neither parents had (TB) than the child could not either because the gene that causes TB was dominant. READ FOLLOWING FOR SURE! There are almost 0 mendelian traits. This still makes it into biology books but they are wrong. The true answer to the question is only that TB is not mendelian, but we do not have enough knowledge of the genetic basis for the trait to say exactly what genes are involved. See link of a great discussion of human "mendelian" traits. http://udel.edu/~mcdonald/mythintro.html

somy · Answer

perhaps child's grandparents had? since genetic code is passed on from one generation to another but it does not necessarily get activated so apparently in child's  parents this gene was not activated while in child this gene got activated 
im just guessing :D