"the first chemicals that provided potential energy on earth may have been formaldehyde and hydrogen cyanide. while these were produced by sunlight-driven reactions, they also occurred around deep-sea vents. if the first organisms on earth evolved around these vents, the first life on earth was "

In the form of bacteria.

Explanation:

Also referred to as the traditional tree of life on earth which is based on the molecular studies the earliest known life forms existed for about 3.5 billion years ago. During the period of the Eoarchean era, when a sufficient amount of the crust had been formed. The earlier evidence so far consisted of microfossils, in the greenstone belts at least around 3.77 billion years ago. The deep-sea hypothesis that is based on the hydrothermal theory posts life may have begun during the submarine vents.