Your Oldest Female Ancestor: Mitochondrial Eve

If we could trace everyone's family trees as far into the past as possible, you’d find we’re all related. Yes, extremely distant relatives. But the common female ancestor from whom all humans are descended is Mitochondrial Eve, and scientists believe she lived in Africa some 200,000 years ago. 

Before people start posting comments here about the Bible and the Garden of Eden, let's say that the idea of a common ancestor has led to the misconception that this ancestor, Mitochondrial Eve, was the first female human, which isn’t correct. She was the most recent common ancestor to whom every living person can trace their genealogy. 

This Eve is technically known as Mitochondrial-Most Recent Common Ancestor, or mt-Eve and mt-MRCA for short, and her lesser-known male counterpart is known as Y-chromosomal Adam. He’s also believed to have lived in Africa, around 150,000 to 300,000 years ago.

Every human on the planet carries the Eve gene, including 147 people and fetuses from the original 1987 study. That study wasn’t the first to hypothesize a common ancestor, but the researchers behind it did coin the term Mitochondrial Eve.

Because one entire branch of the human lineage is of African origin and the other contains African lineage as well, the study's authors concluded Africa is the place where this woman lived. Recent research may have narrowed down this Eve's home as an oasis in the Kalahari Desert, making it the “ancestral homeland of all humans alive today,” according to the researchers. The Kalahari Desert is a vast, semi-arid sandy savanna in Southern Africa, covering a large portion of the region across several countries.

More on the technical details: a “mitochondrial Eve” refers to mitochondrial DNA, the unique genetic code that is passed down from female to female. Mitochondrial DNA, which is responsible for energy metabolism, is cordoned off from the rest of our DNA, sitting off on its own in its own container. 

What about the actual biological Eve? It is not a woman. You would have to seek out the ancestor of our mitochondria. It would be a single cell that engulfed an even smaller single cell and eventually developed a symbiotic relationship that continues to this day. That is what made the ancestor of you, dinosaurs, trees, and butterflies.