Scientists discover ancestor cell of all life on Earth: what is this ancient species? Find out here
In a groundbreaking discovery that advances our understanding of the origin of life, scientists have determined that the Last Universal Common Ancestor of Humankind (LUCA) existed around 4.2 billion years ago, shortly after Earth first formed. The discovery makes it clear that LUCA lived earlier than previously estimated, and sheds light on the complex and dynamic environment in which life emerged.
Common Origin: Characteristics Common to All Life
LUCA, as it is affectionately called by biologists, was not all that different from the more complex bacteria that exist today. It turned out to have several characteristics common to all cellular organisms, including:
- Protein building blocksLUCA utilized proteins, which are the basis of life.
- ATP Energy Use: It relied on ATP as its main source of energy.
- DNA storageLUCA used DNA to store genetic information.
These characteristics suggest that all known life on Earth shares a common origin from LUCA, which was previously estimated to be around 3.9 billion years ago, but dating such ancient biological events has always been difficult.
Published findings and research methods
This study Natural Ecology and Evolution The study, published July 12, aims to refine the timeline of LUCA's existence. The researchers analyzed the genes of 700 species of bacteria and archaea, some of the oldest forms of life, and studied 57 common genes. They also incorporated data from ancient microbial mats estimated to be 3.48 billion years old to support their findings.
LUCA's environment: thriving in extreme conditions
Their research led them to the surprising conclusion that LUCA lived during Earth's Hadean epoch, about 4.2 billion years ago, a period marked by extreme conditions such as:
- Hot SeaLUCA existed in a warm and unstable marine environment.
- Lack of oxygen in the atmosphereEarly Earth had very little oxygen in its atmosphere.
LUCA's habitat likely included environments capable of supporting life in extreme conditions, such as shallow hydrothermal vents and hot springs. LUCA was resilient, able to withstand high temperatures and survive without oxygen, relying instead on the waste of other organisms.
Important Discoveries about LUCA
- Virus protectionLUCA had developed an early immune system that contained genes to ward off viral infections.
- Metabolic pathwaysOther microorganisms use the digested organic matter as an energy source, suggesting a complex ecosystem.
Effects on extraterrestrial life
The discovery that LUCA thrived in such a vibrant and complex environment raises intriguing possibilities regarding extraterrestrial life. Professor Philip Donoghue from the University of Bristol said: “This suggests that life may be thriving in an Earth-like biosphere somewhere in the universe.”
By shedding light on LUCA's ancient existence and environment, this study provides deeper insight into the early stages of life on Earth and inspires further exploration of the possibility of extraterrestrial life.