12 Comedians Who Died Before Their Time. by Patrick Bromley. Updated March 18, 2017. There are comics who work for decades and never produce anything of value, and then there are comics who are brilliant but die tragically before the world really has a chance to see the full extent of what they really could have done.
Your autosomal DNA is a random subset of your mother's and father's DNA (50% from each parent). Two siblings will not have the same results for the same reason that they do not look exactly the same. They do not get the exact same 50% from each parent. Even identical twins don't have exactly the same DNA (only almost exactly the same).
With simple DNA tests, siblings can match at any number of markers. They can match at all, none, or somewhere in between. This has nothing to do with how related they actually are at the DNA level. Siblings are about 50% related.