ENVIRONMENT
WHAT WAS THE FIRST LIVING THING?
How the origin of everything alive on Earth today points to one ancient organism
WORDS SCOTT DUTFIELD
DID YOU KNOW?
The first animal fossil evidence dates back to 574 million years ago
H umans have been trudging around the planet for the last 300,000 years or so, which is a mere fraction of the 4 billion years that life has existed on Earth. Less than 4 million years after the Earth formed, something brought the ingredients for life together. It may have triggered a biological domino effect, culminating in life’s abundance in every corner of the planet. But where and how did it all begin?
If you ask a biologist, they’ll likely tell you that a single cell named the last universal common ancestor (LUCA) is the first organism to have ever existed. This theoretical single-celled organism likely had a simple membrane and used RNA (ribonucleic acid) to store genetic information, much like our DNA (deoxyribonucleic acid). LUCA may have started as a precursor to biological cells, called a protocell. Whereas biological cells are self-contained, gene-filled and able to reproduce, protocells are merely a collection of non-living components.
Did you know?
A typical human cell divides every 24 hours
It’s taken scientists a long time to put an age on a hypothetical cell, but in 2024, researchers added an extra 300 million years to previous age estimates. Now it’s believed that the ancestral origin of all life came about 4.2 billion years ago. This new birthday came from comparing the shared genetic mutations of 700 living species of bacteria and microbes called archaea.