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.
Report Abuse. 1  DNA between siblings are similar if you share the same biological parents. The genetic information you gain comes from both of your parents, and are a result of fertilization of 2 haploid cells fusing to form a zygote that has a diploid number of chromosomes. 2  There are two ways to answer this question.