In search of the origin of life

Where did life on Earth originate? Scientists are beginning to agree on the period, starting with a stone found in Quebec that proved the existence of protocells some 4.2 billion years ago. But what led to LUCA (Last Universal Common Ancestor)? On this point, as this ARTE report shows, researchers disagree.

To create life, three essential ingredients were needed: a membrane to protect the cell from its environment, a metabolism to sustain it and a genetic code. Accordingly, some biologists believe that it was at the bottom of the ocean that everything began, at the time of the primordial Earth. Indeed, it's impossible for anything to appear on the surface, given the absence of an ozone layer protecting us from the Sun's ultraviolet rays. In the depths where the sun doesn't shine, hydrothermal vents (white smokers) would have created the perfect unbalanced ecosystem for carbon and many other elements to amalgamate and eventually create the first metabolism.

However, the other camp finds this explanation muddy, since it doesn't explain the presence of DNA. For them, the primordial soup gave rise to strands of RNA capable of constituting the genetic code, as well as metabolism and the cell membrane. But then again, this theory doesn't elucidate where these first RNAs came from. Some have even compared it to the possibility of a jet plane being built from the passage of a tornado. Could this be a possible hybridization of the two ideas? RNA strands coming from the imbalance that may have clung to the first metabolisms...

Running time: 29:30

Photo: wir0man - DepositPhotos