Bryan Sykes is a pioneer in researching mitochondrial DNA (mtDNA). That is the little extra bits of DNA that are included in mammal cells not within the nucleus. The DNA in the mitochondria is passed down only on the female line, as they are not part of the recombination in sexual reproduction, but are included as part of the egg. Like the amoeba, the mitochondrial DNA only changes due to mutation.

Professor Sykes determined that the 500 base pairs of “junk” mitochondrial DNA mutates slowly and at a pretty constant rate, so he figured that by comparing the “junk” bits of DNA he could figure out if your mother’s mother’s mother’s mother is the same as mine. Well surprisingly enough, those of us of European decent have only seven mitochondrial mothers, and from anywhere in the world only thirty three.

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