Using the word predation may seem surprising when we talk about the first organisms that set out to eat other organisms, for they were not deadly predators with sharp teeth and claws, but small single-celled life forms that swam around in the primordial sea. They had neither a mouth nor a gut system; all they had was a cell membrane so soft that they could engulf another, smaller organism, that they encountered on their way.
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Source: Phys.org