We might not yet know for certain where we came from or how life on Earth had begun in the first place, but throughout history, there have been many theories. The most widely accepted theories are Darwin’s theory of evolution and Creationism. That’s not to say, however, that there haven’t been others. Below you can find five examples of theories about the origins of life on Earth.
A recent study implies that life on Earth began as a result of “organic molecular cocktails” spreading throughout the stars, and some of them ending up on Earth and taking root in the habitable environment. The seeds could’ve been carried via comets or asteroids. Researchers are comparing this notion to an epidemic – life infecting the galaxies, so to speak.
This theory is, as of yet, neither confirmed not disproven, so it’s quite possible that the truth is indeed out there. If it is, it can serve as the official confirmation that we aren’t alone in the Universe!
The essence of the theory of consecutive creations, or catastrophism that originated in France in the 1800s is that the Earth has previously suffered a series of catastrophic events, each of which destroyed the existing life, thereby giving another form of life a chance to develop. If we consider this theory to have some merit, then it carries strong implications that there will be another series of catastrophic events on the Earth soon, if it’s not already happening. This idea that’s quite similar to “The Butterfly Effect” theory predates the theory of evolution, which is not on this list.
This Richard Dawkins-approved theory claims that the organic molecules have formed from the non-organic ones, particularly silicate crystals. The theory originated in the 1980s in Scotland and it kind of goes hand in hand with the DNA’s function of information storage. According to the theory developed by organic chemist Alexander Cairns-Smith, the non-organic clay molecules have arranged the organic ones into certain patterns, and after a while, organic molecules began to organise themselves into DNA patterns that we know today.
Another theory that supports the notion that we have the outer space to thank for existing. Panspermia’s notion is that life is distributed throughout space and time through meteoroids, asteroids and planetoids. The bacteria carried by them, while mostly dormant, are extremely adaptable and if presented with the ideal conditions, they awaken and the evolution process begins.
While this theory, together with the aliens theory, provide a somewhat reasonable explanation for how life began on Earth, it doesn’t really explain how it began in outer space and therefore poses even more questions for scientists.
This is probably the oldest theory on the list – some even claim that it began with Aristotle. The philosopher was a keen observer of nature, which helped him conclude that living matter generated from non-living matter (like mice from rotting hay). The theory had stood the test of time for over 1500 years until it was ultimately disproven by microbiologist and chemist Louis Pasteur in the 19th century. He managed to prove that microorganisms couldn’t develop in vacuum, which earned him the Alhumbert Prize of the French Academy of Sciences.