What percentage of genes do half siblings have in common?

What percentage of genes do half siblings have in common?

That's a bit complicated. You get half of your genes from your mother and half from your father, and your siblings do too, but not necessarily the same 50% from each parent. In fact, almost certainly not the same collection from each. Otherwise you'd be clones (or identical twins, which come from one egg splitting into two exact copies). The statistical chances of that are just about zero for siblings from separate embryos.

Similarly, if you only got all the genes from each parent that your sib did not get, you'd be no more genetically related than you are to a stranger off the street! Again, the chances of that are about zilch.

Normally, you'll get about half of the same genes from each parent that your brother or sister did. Understand, however, that the difference represents only a tiny part of your entire genome. Genetically speaking, the DNA that each of us has is 97% identical to that of a chimpanzee!

That's a bit complicated. You get half of your genes from your mother and half from your father, and your siblings do too, but not necessarily the same 50% from each parent. In fact, almost certainly not the same collection from each. Otherwise you'd be clones (or identical twins, which come from one egg splitting into two exact copies). The statistical chances of that are just about zero for siblings from separate embryos.

Similarly, if you only got all the genes from each parent that your sib did not get, you'd be no more genetically related than you are to a stranger off the street! Again, the chances of that are about zilch.

Normally, you'll get about half of the same genes from each parent that your brother or sister did. Understand, however, that the difference represents only a tiny part of your entire genome. Genetically speaking, the DNA that each of us has is 97% identical to that of a chimpanzee!