Molecular fingerprinting suggests that every life-form on earth today originated from the same bacterialike ancestor. That ancestor eventually led to the three main surviving branches of life, the archaea, bacteria, and eukaryotes (the organisms made of cells with a nucleus that include algae, plants, fungi, and animals).

...in the evolution of organisms and ecosystems there are innumerable random events of history that shape outcome. Outcome is not preordained. There are no correcting factors or laws from above that specify the form of the ultimate outcome...

-Bernd Heinrich -Winter World