Earliest known life forms

Some of the earliest known life forms were very simple, single-celled organisms called prokaryotes. Prokaryotes are like tiny, microscopic bubbles that do not have any kind of structure inside them. They were alive because they could perform some basic functions such as move, eat, and reproduce. They could also take in energy from the sun and use it to create food. Over time, these prokaryotes eventually evolved into more complex forms of life.