> bodies of water

Not proof of life. Just a far better chance that life exists, as we know it.

> vegetation on land

Proof of life. Plants are considered as living things because they fulfill all the characteristics of living things.

Plant life began began colonizing land 500 million years ago, during the Cambrian Period, around the same time as the emergence of the first land animals.

Microscopic organisms (microbes) left signals of their presence in rocks about 3.7 billion years old. Microbes would also be considered life as microbes are social creatures that live in communities shaped by cooperation and competition, and they change their behavior, sometimes for the worse, depending on the company they keep.