Metazoans were the first multi -cellular animals. They could move, respond to their environment, and feed on other organisms. They developed organs, a nervous system, sensory organs, and a brain which led to the development of intelligence. The earliest forms were flat bodied, like today’s flat-worms. Direct fossils of metazoans from later periods have been found. These are fossils of animals that lived in the sea and the seabed, 680 to 570 million years ago. These fossils bear some resemblance to the bodies of some of today’s invertebrates, including some types of jellyfish. These fossils are amongst the earliest discovered of distinct forms of animal life.
Dawn of Life
Stanley Miller, a scientist, devised an experiment to discover the origin of life. He removed all oxygen from his apparatus, which contained the gases that mimic the Earth’s atmosphere. He then mimicked lightening flashes by providing an electrical spark. At the end of the experiment, the apparatus contained complex molecules of the kind that are found only in living things.
