When Did Amoeba First Appear on Earth?

Now scientists have uncovered the earliest ever terrestrial species of an important type known as testate amoebae. The fossil amoebae were found in ancient Scottish rock dating to 400 million years ago, pushing back the origin of the organisms by hundreds of millions of years.

When was the first amoeba?

The earliest record of an amoeboid organism was produced in 1755 by August Johann Rösel von Rosenhof, who named his discovery "Der Kleine Proteus" ("the Little Proteus"). Rösel's illustrations show an unidentifiable freshwater amoeba, similar in appearance to the common species now known as Amoeba proteus.

How did amoeba evolve?

It's a cacophony of random mutations where natural selection favours the ones that are slightly better adapted to their local environment. Amoebas are simpler organisms than humans or pine trees, but they aren't less evolved: they're the result of the same four billion years of evolution as every other living thing.