Geneology and eye color? Am I part Native American?

OK, my father says that his father's mother's mother was Shoshone. My mother says this is not possible, because apparently my brother and I were the only grandchildren on my father's side with brown eyes, which our mother has. My father's eyes are green, same as his two brothers' (who both married blue-eyed women), his father's eyes were blue, and his mother's eyes were green. I do not know the eye color of my father's paternal grandmother, or of any of my father's cousins on the paternal side. My mother's 7 siblings have various eye colors.





From this information, is there any way to tell whether my father's father's mother's mother was Shoshone? If not, what information would I need to determine, by eye color, whether this is possible? I would be proud to have some Native American heritage, but the story's source, my grandad, had a propensity for tall tales, so I don't know what to think...all the family records were lost in a house fire...should I just hire a geneologist?Geneology and eye color? Am I part Native American?
It is possible that your grandfather's mother's mother had brown eyes. If she married a man with blue or green eyes and their daughter married a man with blue eyes then it is possible for your grandfather to have blue eyes. If, however, the suspected Shoshone grandmother married a man with brown eyes then your grandpa would have brown eyes.Geneology and eye color? Am I part Native American?
Brown eyes are dominant (dominant genes that is), so it is not unusual that your brothe and yourself took after your mother and her brown eyes.





I am not sure why you having brown yes, however would negate your father's story. Could you explain why you think so?
As said above, eye color is a bad indication of genetic background. There any number of genetic markers which can be associated with any racial grouping of people. They might not be able to tell you if you are Shoshone in particular, but they might be able to ascertain if you are of general Native American stock. So don't go to a geneologist. Go to a geneticist (or even a physical anthropologist).
It looks like you've made the assumption that all Shoshone have brown eyes. That's probably not true, but let's assume that all Shoshone do have brown eyes and, furthermore, that they have no recessive genes anywhere in their heritage, which is also not really true. In that case, any Shoshone can only have children with brown eyes, because of the dominance of brown in eye color. However, if the other parent of that child is not a Shoshone, the child might have a recessive gene for a lighter eye color. If the child has a child with a non-Shoshone, the grandchild could have any eye color, because the first child can contribute a recessive gene and that child's spouse can contribute any gene from the non-Shoshone population.





You only know about the eye color of your father's father's mother, which are green. She is supposed to be the daughter of a Shoshone, which should make it impossible for her to have green eyes. However, the brown eye gene can actually manifest as green eyes under the right circumstances, because there are multiple genes involved. So the green eyed daughter of the Shoshone woman is a possibility, and you cannot disprove the possibility that your ancestor was a Shoshone by this method. Nor can you prove it. Many people have brown eyes and are not Shoshone. If you really want to know, then you might indeed need a geneologist.