Breaking: Supreme Court OK’s taking DNA upon arrest

[jeff47]

155. Mitochondrial DNA is not used for identification

Because it's highly conserved.

Translated to English: Everyone's mitochondrial DNA is nearly identical. That makes it nearly useless for identification. Their example of a mother and her two kids is wrong. Because it doesn't go nearly far enough.

Let's say your suspect has siblings. They have identical mitochondrial DNA. As does their mother. As does their grandmother. As does their aunts and uncles. As does their cousins. As does their great aunts and great uncles. And so on.

Vast swaths of your family tree have the same mitochondrial DNA. The mutation rate is so low that you and your great, great, great, great grandmother probably have identical mitochondrial DNA. Along with every one of her descendants.

Further, let's say your family's Italian. Virtually all Italians will have nearly identical mitochondrial DNA. Which means you'd have to completely sequence the mitochondrial DNA in order to narrow down "all Italians" to "a massive swath of your family tree". Doesn't sound like a good use of $100k or so.