Question

Unicellular organisms evolved earlier than multicellular organisms around 3.5 thousand million years ago. Justify.

Answer 1

The first known single-celled organisms appeared on Earth about 3.5 billion years ago. The inorganic molecules are believed to react in the existing environmental conditions to form amino acids which then formed protein and that evolved into the single cell. More complex forms of life took longer to evolve, with the first multicellular animals not appearing until about 600 million years ago.