👉 In the context of biology, a protogenist is someone who believes in the existence of life on Earth and that all living organisms are part of a single, ancient evolutionary tree. They believe that the development of life on Earth began with the appearance of prokaryotic cells (organisms without a nucleus) at the beginning of the Cambrian period around 540 million years ago. This theory is supported by the fossil record and other evidence, including the presence of ribosomal RNA in some