Chapter 29, Problem 6TE

What was the most noteworthy evidence of life in the Precambrian?

To determine

The most trustworthy evidence for life in the Precambrian.

Answer to Problem 6TE

The most trustworthy evidence for life in the Precambrianincludes fossils of algae like creatures called stromatolites and of soft-bodied animals that lied in shallow waters.

Explanation of Solution

The Precambrian time range approximately 4.5 billion years ago. In the mid-Precambrian, known as Archean eon, the surface of Earth began to cool. This allowed the formation of oceans, and with the cooling temperature, water vapor in the atmosphere condensed to form the cloud. During the Archean, colonies of organisms like cyanobacteria who could survive without the presence of much oxygen lived, and fossils of these life forms called stromatolites have been found in Western Australia. These fossils have been dated back to be from around 3.5 billion years. Towards the end of the Precambrian, evolution produced single-celled organisms and primitive multicellular organisms too. This was during the Proterozoic period, and fossils of soft-bodied animals have been found from Proterozoic rocks from Australia.

Conclusion:

Therefore, the most trustworthy evidence for life in the Precambrian includes fossils of algae like creatures called stromatolites and of soft-bodied animals that lied in shallow waters.