The first living cells to evolve on earth were single celled bacteria. These single celled organisms developed specialized structures to trap sunlight energy and to carry out photosynthesis e.g mitochondria, chloroplasts and lead to the development of multicellular organisms known as plants which are included in eukaryotes. All these changes have been found in fossil records of primitive organisms.
The first living things on Earth, single-celled micro-organisms or microbes lacking a cell nucleus or cell membrane known as prokaryotes, seem to have first appeared on Earth almost four billion years ago, just a few hundred million years after the formation of the Earth itself.
