Same-sex unions are recorded in the history of a number of cultures, but marriage or similarly formalized same-sex unions were rare or nonexistent in other cultures.
Using this measure, siblings are actually 99.95% the same. The 50% refers more to the amount of DNA we get from mom and the amount we get from dad. So we are more similar to our relatives than we are to a mouse. Let's explore in a bit more detail what the 99.95% and the 50% numbers mean.
Judith McCann. answered on 15 Jun 2011: No,Two people can have similar DNA if they are closely related (brothers/sisters) but they will never be exactly the same unless the two people are identical twins. Everyoneâs DNA is a contribution from both parents, and your parents DNA is a contribution from both grandparents.