here Josh-D. Davis says:
On average, you share 50% with each. In reality, you share 45–55% with a parent, and 32–49% with a sibling.
( to question "How similar is one's DNA to their parents and siblings?" )
i belive this is true... can you show this with some examples, combinatorics, statistics, calculations?
( if this is not true, then take this question like: what is genetical distance of one's sibling to him compared to genetical distance of their parent's? )
i thought about this and i come to conclusion that distance of a sibling (with both parents same) is almost/roughly like distance of a parent. but i used to thing about this distance as "1" distance, not "50%". "50%" does not look very right for me, because all people share like 99% of genes, (and it is even like 99% with chimpanzees).
if distance of a parent is 1, then, distance between siblings through him is 2, and 2 parents look like parallel resistors, so, i see the "resistance" through both parents should be 1.
but if i try to think about how dna is divided during meiosis, it seems not so easy. there maybe some amount of genes that never change, from parents to child, and some that change. if i assume there are 100 genes that may change... some of them of a parent maybe same in both alleles, some different... if i assume 40 of them are different, 60 same, then... i do not know, in which amounts that really happen. and another parent also has some other genes... how much genes a parent loses in meiosis in average? how much genes are usually shared between parents? there might be some parameters that are different in different nations, locations, and depending on how distant are parents genetically from each other... you can use either example/bogus numbers, or just latin letters (variables), or can give some real data... (i think, additional answers with additional data should be welcomed... i do not know, what is rules in this stackexchange about this.)