It's only math. Staying within genetic outcomes of ancestral lineages occupying time in the atmosphere daily here
Each son or daughter has 2 parents.
Any siblings of a son or daughter share at least one of the 2 parents biologically here.
The two parents from the same process regardless how many siblings in previous generation had two parents that become the grandparents of each last son or daughter added to the species so far. 3 generation gaps living same rotations alive biologically are specifically 6 prior people lived for each grandchild added in direct sequence to numbers living in all 3 generation gaps of one family unit having a population that adds all the combinations together each rotation forward.
Add a 4th generation gap and the biological numbers become 14 previous ancestor sharing DNA with the new arrived each great grandchild. Expand that to 5 generation gaps and chromosome relativity become 30 in each great great grandchild.
No great great grandchild born ever gets conceived again while they may conceptualize themselves as larger than their time living in plain sight.
Oh Look! original sin is self deception practiced ancestrally forward socially in every reality here today.