The video explains how to navigate family relationships using a diagram. It begins with the individual, parents, and grandparents, then moves on to aunts, uncles, and cousins. The presenter explains that the degree of cousinhood is determined by the number of generations it takes to reach a common ancestor, and the removal is determined by the difference in generations between the two individuals.
The video explains that:
* First cousins are the children of aunts and uncles.
* First cousins once removed are the children of first cousins.
* Second cousins are the children of first cousins once removed.
* Third cousins, fourth cousins, and so on, are determined by the number of generations it takes to reach a common ancestor.
The presenter also explains that the amount of DNA shared between relatives can be estimated by tracing the journey up to the most recent common ancestor and then down to the relative. The video concludes that all humans, and even all living organisms, are related and share a common ancestor that dates back to the Big Bang.
The presenter also mentions that siblings can be considered zeroth cousins, and that it's theoretically possible to be one's own negative first cousin, but only in a humorous and not literally sense.
1. The audio is discussing the concept of cousins and how they are related through a family tree.
2. A person shares 50% of their DNA with each of their parents.
3. If a person has children, they will share 50% of their DNA with each of their children.
4. A person's siblings are on the same row as them on a family tree because they are in the same generation.
5. A person's siblings descend directly from their parents, just like they do.
6. The children of a person's siblings are their nieces and nephews.
7. A person's grandparents may have had kids that weren't their parents, and those children are called their aunts and uncles.
8. A person's great-grandparents' children that are not their grandparents are called their grand aunts and uncles.
9. A most recent common ancestor is someone that two people directly descended from.
10. The degree of cousinhood is determined by the number of generations that two people must pass through to reach their most recent common ancestor.
11. The removal of cousinhood is determined by the difference in the number of generations that two people must pass through to reach their most recent common ancestor.
12. Children share half of their DNA with each parent and about half of their DNA with a sibling.
13. Every individual alive today has a genome that is more than 99% similar to every other person alive today.
14. When discussing DNA shared between two people, it is referring to the proportion of the less than 1% that makes them unique individuals.
15. A person shares about 25% of their genetic makeup with their aunts and uncles.
16. A person shares about 12.5% of their genetic makeup with their first cousins.
17. A person's siblings can be considered their zeroth cousins.
18. All people, and even all living organisms, share a common ancestor and are therefore related.