One man who managed to stir some doubt was Niels Stensen (or Nicolaus Steno).
Really far back in time, there wouldn't be any legs at all, just fins for swimming.
Evolutionary theory argues that all the organisms alive on Earth today share a common ancestor.
Furthermore, many animals — giant ground sloths in South America, monstrous reptiles in England — had gone extinct long ago.
So even if people continued to look to the Bible for spiritual guidance, they began to doubt it was a literal account of the history of life on Earth.
But if you were to go back further in time, a couple million years before anybody figured out how to write, your ancestors would still have two eyes, two ears, a nose, a mouth, a head sitting atop an oblong body with two arms and legs. If you went further back in time, the arms would be front legs.
Even further back in time, the fur would be scales.
By the early 19th century, a different picture had emerged of the planet's history.
Lead by scientists like Buffon, George Cuvier and James Hutton, the men (few women could participate then) who studied rocks and fossils accepted that the Earth had been around for thousands, if not millions, of years before people came on the scene.
After all, fitting two of everything living in Europe was enough of a challenge.