[katieHaylor (OP)]

Donald says:

I know that mitochondria - often called the powerhouses of cells - live inside our cells. But do mitochondria have any relatives that live outside our cells, or even outside the body? What are mitochondria like in other species? Have they evolved differently?

What do you think?

[evan_au]

Mitochondria are dependent on their host cell for most functions.
They have lost most of the DNA that would allow you to identify closely-related but independently-living species.

But there is a possible ancestral tree proposed here:
https://en.wikipedia.org/wiki/Mitochondrion#Origin_and_evolution