My oldest granddaughter, Leanna, has two copies of a recessive gene on chromosome 16. This genetic condition caused a mutation in the MC1R protein.
In short, she's a redhead.
While none of her parents, aunts, uncles, or grandparents have red hair, it's not really a surprise, given her ancestry. There's a lot of the British Isles in her. According to Wikipedia, 13% of the population of Scotland has red hair and 40% carry the recessive redhead gene; 10% of the Irish population has red, auburn, or strawberry blond hair while a whopping 46% of the Irish population carries the recessive redhead gene.
After a generation or two of dominant eastern European genetic influence, the Scots/Irish ancestry is making a spectacular comeback.
The photo is by Melissa Butscher Photography. Check out her website and blog, which explains "Project Red."