The 1840 Census asks about names and ages of Pensioners for Revolutionary or other Military Service.
Know your relationships: An ancestor is a person from whom you are descended. A descendant is a person who is descended from an ancestor. A relative is someone with whom you share a common ancestor but who is not in your direct line.
DNA Sequencing is a laboratory technique used to determine the exact sequence of bases (A,C,G and T) in a DNA molecule. The technology of DNA sequencing was made faster and less expensive as a part of the Human Genome Project.
X chromosome: One of the two sex chromosomes, X and Y. The X chromosome is passed down from mother to child. X is the sex chromosome that is present in both sexes, singly in males and doubly in females.
When it comes to spelling variations, be creative. Often clerks and government officials were unable to correctly record the names given them by unschooled immigrants not familiar with languages used in their port of entry. The surname was written down as the official heard it and the immigrant accepted that as the official American rendering of his name.