Same-sex marriage, also known as gay marriage, is marriage between people of the same sex, either as a secular civil ceremony or in a religious setting. 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.
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.
Legally your kids and your sisterâs kids are first cousins but at the DNA level they are half siblings. They share twice as much DNA as run of the mill first cousins! What I thought Iâd do for the rest of the answer is go into a bit more detail about why you and your sisterâs kids share 25% of their DNA.