8 Disgusting Things Living On Your Body Right Now

4. Mitochondria (Are The Powerhouse Of The Cell): Alien Bugs

We don't just play host to a bunch of microbes - they're actually a part of our living cells.

Unless you literally slept through high school (entirely possible), you'll know that the mitochondria are the powerhouse of the cell, but they also began life as a completely separate entity, as a single celled organism.

In the chaos of the primordial soup, this single celled organism bumped into a different single celled organism and was swallowed by it. Far from being the end, the mitochondria found that it liked its new home and the two began a symbiotic relationship, with the mitochondria becoming the energy generators and eventually creating the conditions for multicellular life (that's you).

The DNA of mitochondria is still different to the nuclear DNA that you inherit from your parents, and you can only inherit your mitochondrial DNA from your mother. This allows scientists to trace DNA through the mother line of humans, and even track our migrations around the planet over hundreds of thousands of years.