A theory is a set of sentences which is closed to make logical implications.
Mitochondria are unusual organelles. They act as the power plants of the cell, are surrounded by two membranes, and have their own genome. They also divide independently of the cell in which they reside, meaning mitochondrial replication is not coupled to cell division. Some of these features are holdovers from the ancient ancestors of mitochondria, which were likely free-living prokaryotes.
The first species that colonizes new of undistributed land is called as pioneer species, or simply pioneers. If you check the meaning of pioneer, it's a type of person or entity that became the first to explore or exploit a certain something. In this case, they were the first species who explores the lands to create a society.
