What is the first living things on earth?

Answer 1

These biota are known as prokaryotes, and modern thought divides them into Archaea, and bacteria. They lack a nucleus and DNA, and are resistant to a wide range of environments.

They precede algae in evolution.

That's a hard questionThe above answer addresses the question "What are the most primitive/simple living things on earth today?". We can't know what life was on earth 4 billion years ago. But whatever the first lifeform was, it must have been far simpler than anything we see today - so simple, in fact, that it couldn't possibly survive today. Basically, if you want to have any hope of guessing what it was like, you need to abandon all preconceptions about cells and possibly DNA. You also need to abandon the idea that there's a big gap between life and non-life. So even if we all knew exactly what happened back then, we might not agree on which step was the "first living thing". PossibilitiesBefore life appeared on earth, the organic material which now forms part of all living things would have existed mostly as simple organic compounds in the sea. The replication of DNA (or something equivalent) could have been catalysed by changes in temperature or concentration. For example, a solution containing single-stranded DNA and free DNA bases, when frozen, could have formed double-stranded DNA; thawing could then have split the strands apart to form single strands again. Or maybe the same effect could have been achieved in small puddles which were sometimes dried up (creating double strands) and made wet again (splitting the strands apart). There may have been minerals which catalysed these reactions.

Answer 2

The first living things on Earth were unicellular microorganisms called prokaryotes. They were born in water.