(c. 610 BC c. 546 BC)
Anaximander speculated about the beginnings and
origin of animal life. Taking into account the existence of fossils, he claimed that animals sprang out of the sea long ago. The first animals were born trapped in a spiny bark, but as they got older, the bark would dry up and break.
[37] As the early humidity evaporated, dry land emerged and, in time, humankind had to adapt. The 3rd century Roman writer
Censorinus reports:
Anaximander of Miletus considered that from warmed up water and earth emerged either fish or entirely fishlike animals. Inside these animals, men took form and embryos were held prisoners until puberty; only then, after these animals burst open, could men and women come out, now able to feed themselves.
[38]
Anaximander put forward the idea that humans had to spend part of this transition inside the mouths of big fish to protect themselves from the Earth's climate until they could come out in open air and lose their scales.
[39] He thought that, considering humans' extended infancy, we could not have survived in the primeval world in the same manner we do presently.
Even though he had no theory of
natural selection, some people consider him as evolution's most ancient proponent. The theory of an aquatic descent of man was re-conceived centuries later as the
aquatic ape hypothesis. These pre-Darwinian concepts may seem strange, considering modern knowledge and scientific methods, because they present complete explanations of the universe while using bold and hard-to-demonstrate hypotheses. However, they illustrate the beginning of a phenomenon sometimes called the "Greek miracle": men try to explain the nature of the world, not with the aid of myths or religion, but with material principles. This is the very principle of scientific thought, which was later advanced further by improved research methods.