LiveScience.com – Conventional wisdom has it that the first animals evolved in the ocean.

Now researchers studying ancient rock samples in South China have found that the first animal fossils are preserved in ancient lake deposits, not in marine sediments as commonly assumed.

These new findings not only raise questions as to where the earliest animals were living, but what factors drove animals to evolve in the first place.

For some 3 billion years, single-celled life forms such as bacteria dominated the planet. …