New Study Reveals the Last Universal Common Ancestor Lived Billions of Years Ago
A groundbreaking study conducted by biologists Tara Mahendrarajah and Anja Spang from the NIOZ, in collaboration with researchers from universities in Bristol, Hungary, and Tokyo, has shed light on the origins of life on Earth. Their findings, published in Nature Communications, suggest that the Last Universal Common Ancestor (LUCA) lived between 4.32 and 4.52 billion years ago.
The study utilized a novel molecular dating approach to estimate the precise timeline of when LUCA split into bacteria and archaea, as well as when eukaryotes emerged. LUCA is believed to have been a primitive cell with ribosomal proteins and an ATP synthase, which are shared by all bacteria, archaea, and eukaryotes.
One of the key revelations of the research is that the ancestors of all current archaea lived between 3.37 and 3.95 billion years ago, making them younger than the ancestors of bacteria. This challenges previous assumptions about the evolutionary timeline of these organisms and prompts a reevaluation of our understanding of early life on Earth.
Furthermore, the last common ancestor of eukaryotes, including plants and animals, is estimated to have lived between 1.84 and 1.93 billion years ago. This finding supports the theory that eukaryotes are a fusion of branches that originated from bacteria and archaea, rather than a separate branch on the tree of life.
These insights into the origin and evolution of different cell types have important implications for understanding biodiversity and the functioning of ancient and extant microbes in nutrient cycling. Furthermore, the study contributes to our ability to predict the future biodiversification in a changing environment, including climate warming.
“With the knowledge of how cells have evolved over time, we can better understand the mechanisms of adaptation and potentially predict how different organisms will respond to environmental changes,” said Mahendrarajah.
The study’s findings mark a significant step forward in our understanding of the complex history of life on Earth. By refining models on eukaryotic origins, scientists can now paint a more accurate picture of the ancient world and how it has shaped the biodiversity we see today. As our world continues to face environmental challenges, this research provides crucial insights into the resilience and adaptability of life on Earth.
