In this week’s Laurel Star was an interesting article called “The genetic effects of having related parents” by Dr. Anthony Policastro. Now this is an interesting Genealogy topic. We know Delmarva was an isolated area cut off from the mainstream population until the widespread use of the automobile. The available selection of people of marriageable age was smaller due to the smaller population in the area. As such marriages between cousins (consanguinity) did occur. Consanguinity occurred most often doing the initial settlement of Delmarva in the 1600’s. When you look at family trees in that time period, simply because of the limited number of families in the area, cousin marrying was much more common. Not only was the relationship between families established by blood it was also established by naming convention of the time. Typically in tracking my family tree on the Eastern Shore of Virginia I encounter intermarrying of the Bayly’s and Scarbourghs family. Sometimes when that occurred the offspring of say; a Bayly female and a Scarbourgh male, that offspring, rather male or female, would be named Bayly Scarbourgh thus establishing the relationship of this offspring to the world or at least to the Eastern Shore of Virginia.
In Policastro’s article he speaks of consanguinity, which refers to children born of related parents. He also speaks about first cousin marrying and their offsprings having 25% common genes which would include abnormal genes. For second cousins about 12% of the genes are common. Third cousins are at 6%, fourth cousins are at 3% , fifth cousins are at 1.5% and so on. He points out it is important to give any degree of consanguinity to your doctor. This is but another reason for family tree research; it helps you avoid marrying your cousin. Laugh but in today’s world where divorce is more common than marriage, the frequency of mixed (as in your kids, my kids, our kids and kids that just tagged along from a previous divorce) marriages, unmarried woman having babies without naming the father, and the lack of close extended family contact, determining who your cousins are is more difficult. This is but another good reason to attend that family reunion.