Life on Earth has always fascinated scientists. This is especially true when it comes to understanding how complex organisms first emerged. Moving from simple, single cell life The vast diversity of plants, animals, and fungi that we see today remains one of the most interesting questions in biology. Recent discoveries point to a link between oxygen levels and the emergence of more complex life forms, highlighting important aspects of this evolution.
The Oxygen Connection: How Asgardian Archaea Shaped Eukaryotic Evolution
discovery of Oxygen loving Asgard archaea It has the potential to reshape our understanding of the complex origins of life. Traditionally, these microorganisms were associated with the anoxic environment of the deep sea and were thought to be able to survive without the need for oxygen. However, this new research reveals that some members of the Asgard group can utilize oxygen. Brett BakerAs an associate professor of marine science at the University of Texas at Austin explains:
“Most Asgardians alive today are found in oxygen-free environments. However, we found that Asgardians, our closest eukaryotic relatives, lived in areas with oxygen, such as shallow coastal sediments or floating in the water column, and had many metabolic pathways that used oxygen. This suggests that our eukaryotic ancestors likely had these processes as well.”
The ability of these ancient microorganisms to use oxygen suggests that the ancestors of complex life had already evolved mechanisms to harness the energetic benefits of oxygen. as oxygen level As the atmosphere rose, these microorganisms could tap into this new energy source, and this may have been an important step in the evolution of more complex life forms.
Credit: University of Texas at Austin
Increasing oxygen levels: catalyst for complex life
The link between rising oxygen levels and the emergence of complex life is a theory that has been debated by scientists for many years. This study provides additional evidence to support this theory, showing that Asgardian archaea, microorganisms that are close to the evolutionary ancestors of eukaryotes, thrived in oxygen-rich environments. These findings are consistent with the geological record, which shows that oxygen levels increased significantly during the Great Oxidation Event more than 1.7 billion years ago.
Professor Baker said: “This fits well with the fact that some of our Asgardian ancestors had access to oxygen. Oxygen appeared in the environment and Asgardians adapted to it. They saw an energetic advantage in using oxygen and then evolved into eukaryotes.” This process of adaptation to oxygen-rich conditions may have provided the energy needed for the development of complex cellular structures and ultimately gave rise to multicellular organisms.
The importance of genome sequencing in elucidating Asgard archaea
The discovery of oxygen-using Asgardian archaea was a direct result of a large-scale genome sequencing effort that allowed researchers to uncover its patterns. DNA These microorganisms have been hidden until now. The research team analyzed more than 13,000 new microbial genomes, doubling the known genetic diversity of Asgardian archaea and uncovering previously unknown metabolic pathways.
Kathryn Appler, co-author of the study and postdoctoral fellow at the Institut Pasteur in Paris, explains the importance of these efforts:
“These Asgardian archaea are often missed by low-coverage sequencing efforts. Large-scale sequencing efforts and layering of sequence and structural techniques have allowed us to see patterns that were not visible before this genome expansion.”
Expanding our understanding of the genetic structure of Asgardian archaea provides new insights into their evolution and relationships with eukaryotes, further strengthening their role in the development of complex life.
Credit: University of Texas at Austin
Artificial intelligence in genomic research: an innovative approach
One of the most innovative aspects of this study was the use of artificial intelligence (AI) to predict the structure of proteins produced by Asgardian archaea. The researchers used the AI system AlphaFold2 to analyze the three-dimensional shape of proteins involved in oxygen metabolism. These structural predictions revealed that several proteins produced by Heimdallarchia, a group of Asgardian archaea, closely resemble proteins used by eukaryotic cells for oxygen-driven energy production.
This breakthrough demonstrates the power of AI in understanding the molecular mechanisms underlying the evolution of life. By predicting the protein’s structure and comparing it to known eukaryotic proteins, the researchers provided further evidence that the ability to utilize oxygen was a key step in the emergence of complex life forms.