Question

How old are the first Bacteria?

Answer 1

Bacteria:

1. The first living thing on Earth was a bacterium.
2. Three billion years ago, they first appeared in the seas of the ancient oceans.
3. At first, only anaerobic heterotrophic microorganisms were present (the primordial atmosphere was virtually oxygen-free).
4. The first autotrophic bacteria, which are quite similar to the cyanobacteria of today, emerged about 2 billion years ago.
5. These species engaged in photosynthesis, which resulted in an increase in the amount of beneficial oxygen in the atmosphere.
6. Blue algae and cyanobacteria created the first breathable atmosphere, enabling life to flourish in the regions above the sea.
7. Before the introduction of the microscope, bacteria were too small to be observed or studied, therefore man just recently learned of their existence.
8. The earliest cyanobacteria-like fossils are nearly 3.5 billion years old, making them among the oldest fossils ever found.
9. The cyanobacteria, sometimes known as "blue-green algae," have a long fossil history extending back to the Precambrian epoch.