How Two Brown Eyed Parents Can Have a Blue Eyed Baby

When my husband and I had our son numerous family members told us that his tiny blue eyes would eventually turn brown. My husband and I both have brown eyes so individuals who were unfamiliar with genetic laws assumed that two brown eyed parents would inevitably have a brown eyed baby.

When weeks turned into months and our son's eyes actually turned lighter blue rather than darkening to a shade of brown we had some individuals joke about the paternity of our child. While they may have done so in a humorous manner I did not find the comments funny at all. My husband and I are deeply in love and in both of our lives we have only had intimate relations with each other. The implication that my son might not be my husband's child was both insulting and offensive to me. After the first comment was made I thought back to my high school biology classes and remembered that both dominant and recessive genes could affect eye color. I then did a little bit of research so I could give and intelligent, scientific reason for my son having blue eyes.

When humans are born we inherit genes from both parents. Some genes are considered to be dominant and some are recessive. Dominant genes are more likely to produce a certain characteristic than a recessive gene. For instance, the gene for brown eyes is dominant over the gene for blue eyes or green eyes. The gene for green eyes is more dominant than the gene for blue eyes.

Two brown eyed parents can produce a child who has blue eyes if they each have a blue eyed parent of their own. This is the case for my husband and me. My husband's mother has blue eyes (b) and his father has brown eyes (B). Thus the genes he can pass on to his offspring are Bb. My mother has brown eyes (B) and my father has blue eyes (b). The genes I can also pass onto my children are also Bb. This means that our children could be born with either brown eyes (BB) or blue eyes (bb) even though we both have brown eyes.

Science Daily reports in an article from October 23, 2006 that two brown eyed parents who each carry a recessive blue eyed gene from one of their own parents have a 25% chance of having a child born with blue eyes. It is much more likely that two brown eyed parents will produce a brown eyed child because the gene for brown eyes is dominant, but as long as each parent also carries a recessive gene there is very real possibility they will have a blue eyed baby.

We had a second baby when our son was eighteen months old and though she is only nearing her fifth month of life we can already see that her eyes are turning brown. Unlike her big brother she inherited the dominant brown gene that we both carry. Biologically they are similar because they both carry our genes but the characteristics we passed on to her are different than her brother. Each has their own unique features that make them special and beautiful.