Humans evolved from other apes about 2 and a half million years ago. Since then several other forms of humans have evolved, with the only ones now left on the planet being us (Homo sapiens), after Neanderthal dies out only 30,000 years ago which isn’t that long compared to the age of Earth.
Going further back, more complicated life like ourselves, is thought have evolved from bacteria. Bacteria have a protein called haemoglobin which is very similar to the haemoglobin in our blood that carries oxygen around the body. Our blood in a sense then, came from bacteria.
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