Ancestral alleles are shown in grey and derived (non-ancestral) alleles are shown in blue. As a new positively-selected allele (red) rises to high frequency, nearby linked alleles on the chromosom ...

Alleles are different forms of the same gene, for example blue and brown are both alleles ... Dominant alleles will be expressed even if a recessive allele is present. Recessive alleles will ...

The merle allele takes the eumelanin and dilutes it into a shade of gray or blue. There are two major types of Blue Shelties. Blue merle Shelties will have gray, tan, and white double coats.