I recently saw a posting (somewhere) that identified how much of a parent's DNA was passed on if there were multiple children. A single child will have 50% of a parent's DNA. If there are 2 children something in the range of 73-75% of the parent's DNA has been passed on. This increases to over 90% if there are 4 children. Can anyone give me the figures that were published and the source? Thanks.

On Sun, Dec 27, 2015 at 6:07 PM, Linda Reid via <genealogy-dna@rootsweb.com> wrote: > I recently saw a posting (somewhere) that identified how much of a > parent's DNA was passed on if there were multiple children. A single > child will have 50% of a parent's DNA. If there are 2 children something > in the range of 73-75% of the parent's DNA has been passed on. This > increases to over 90% if there are 4 children. Can anyone give me the > figures that were published and the source? Thanks. The source is pure logic. If we ignore the X-Y dimorphism, exactly 1/2 of a parent's DNA is passed on to any given child, and, by the same token, the probability is exactly 1/2 that any particular bit of DNA is passed on to a specific child. Thus, the probability that a particular bit of DNA is *not* passed on to any of N children is 2^-N. That is, the expected total amount passed on is successively 1/2, 3/4, 7/8, 15/16, and so on. However, the range of possible total passed on to two or more children is always 50% to 100%, regardless of how many there are (that is, if more than one, and counting identical twins as just one per pair). What happens as more children are added is that the likelihood of 50% total coverage falls while the likelihood of 100% coverage rises. John Chandler