Evolutionary riddle Solved: Photosynthesis and Aerobic Metabolism Linked by ancient molecule

Published: February 28, 2025

Jakarta – The long-standing debate about the origins of photosynthesis and aerobic metabolism has taken a dramatic turn. Researchers have discovered a previously unknown molecule that appears to bridge the gap between these two essential life processes. This finding challenges existing theories about how organisms first began to utilize oxygen on Earth, perhaps rewriting the evolutionary timeline.

The central question revolves around the relationship between photosynthesis, used by plants and algae to convert sunlight, carbon dioxide, and water into energy, releasing oxygen as a byproduct, and aerobic metabolism, the process by which animals use oxygen to break down fuel for energy, releasing carbon dioxide. The new research suggests these processes might potentially be more intertwined than previously thought.

Felix Elling, a researcher from the department of Earth and Planet science, initiated the research with a specific goal. We suspected this was related to the evolution of photosynthesis and breathing skills, Elling said, highlighting the initial hypothesis driving the investigation.

While working in Professor Ann Pearson’s Lab for Molecular Biogeochemistry and Organic Geochemistry, Elling made a surprising observation. While analyzing a nitrogen-utilizing bacterium called *Nitrospirota*, he detected an unusual change in a molecule. This change resembled a characteristic typically associated with photosynthesis in plants, rather than a process found in bacteria.

Elling described the unexpected shift as an infinite change in nitrospirota molecules, emphasizing the unusual nature of finding plant-like characteristics in bacteria that consume nitrogen. This observation sparked a deeper investigation into the molecular mechanisms at play.

The team’s investigation focused on quinones, molecules present in all known forms of life. Quinones exist in two primary forms: aerobic quinones, which require oxygen, and anaerobic quinones, which do not. Aerobic quinones are further divided into those used by plants for photosynthesis and those used by bacteria and animals for oxygen inhalation.

The groundbreaking discovery was the identification of a third type of quinone: methyl-plastohydroquinone. Researchers believe this molecule represents a previously unknown, lost chain in the evolutionary process, potentially linking photosynthesis and aerobic metabolism.

The presence of quinones related to photosynthesis in oxygen-inhaling bacteria is notably important. Researchers now hypothesize that methyl-plastohydroquinone represents a missing link between the two critical life processes of photosynthesis and breathing,suggesting a shared evolutionary origin or an earlier capacity for oxygen utilization than previously believed.

This finding has been connected to the large oxidation events that occurred approximately 2.3 to 2.4 billion years ago.Scientists believe that during this period, cyanobacteria algae emerged and produced vast quantities of oxygen. This surge in oxygen levels paved the way for the evolution of organisms capable of breathing, or aerobic metabolism.

Previously, the prevailing theory suggested that photosynthesis preceded the emergence of oxygen-utilizing life forms. Though, the discovery of this new type of quinone proposes a revised hypothesis: organisms capable of utilizing oxygen existed long before the cyanobacteria explosion, potentially influencing the conditions that allowed cyanobacteria to thrive.

Ann Pearson, from the lab for molecular biogeochemistry and organic geochemistry, elaborated on the challenges of early oxygen utilization. She explained that biological reactions utilizing oxygen are very destructive and can harm cells unable to process it. Therefore, organisms that could process oxygen possessed highly sophisticated cells.

In other words, this is the way we breathe. After having the ability to breathe,diversify all kinds of life in this world is open, Pearson said,highlighting the profound impact of this evolutionary adaptation and the significance of understanding its origins.

The variations in quinone structures are also evident in the human body. quinones found in human mitochondria differ from those found in plants, reflecting the divergent evolutionary paths these organisms have taken.

What we find is the ‘ancestor’ of this molecule, which is then adapted into two forms with specific functions in plants and in the form of mitochondria, Elling said.This molecule is a time machine, a living fossil from molecules that last more than two billion years. This highlights the profound implications of the discovery for understanding the deep history of life on Earth.

Unearthing Life’s Breath: A Revolutionary Finding Linking Photosynthesis and Aerobic Respiration

Did you know that the very air we breathe might share a surprisingly ancient connection with the process that fuels plant life? This groundbreaking discovery challenges our understanding of evolution and opens up exciting new avenues of research. Let’s delve into this fascinating revelation with Dr. Evelyn Reed, a leading expert in molecular biogeochemistry and evolutionary biology.

World-Today-News.com: dr. Reed,the recent discovery of methyl-plastohydroquinone as a potential “missing link” between photosynthesis and aerobic respiration is nothing short of revolutionary. Can you explain the significance of this finding in simpler terms?

Dr. Reed: Absolutely. the finding of methyl-plastohydroquinone is meaningful because it suggests a much closer evolutionary relationship between photosynthesis—the process used by plants and algae to convert light into energy—and aerobic respiration—the process by which animals and some bacteria use oxygen to produce energy. For decades, these processes were considered largely independent evolutionary events. This new molecule, however, indicates they might have a shared, ancient ancestor. The discovery challenges the existing notion that photosynthesis emerged before the utilization of oxygen for respiration, potentially suggesting a more simultaneous, or even a reversed, timeline. Think of it as finding a common ancestor in our family tree that we previously didn’t know existed; it fundamentally reshapes our understanding of the progress of life on Earth.

World-Today-News.com: How does this discovery relate to the Great Oxidation Event, approximately 2.4 billion years ago? What impact does it have on our understanding of that pivotal moment in Earth’s history?

Dr. Reed: The Great Oxidation Event, when the Earth’s atmosphere became significantly oxygenated, largely attributed to cyanobacteria, is a central element of this newfound understanding. The traditional view placed the evolution of oxygen-utilizing life after the cyanobacterial oxygen surge. However,the discovery of methyl-plastohydroquinone suggests an earlier capacity for oxygen utilization might have already been present. This doesn’t mean oxygen-breathing life existed before the Great Oxidation Event, but it implies the necessary biochemical machinery for oxygen use may have appeared earlier than previously thought. Perhaps this early oxygen utilization capability played a role in setting the stage for the very conditions needed for the explosion of oxygen production by cyanobacteria, rather than evolving solely because of their oxygen production. This finding significantly alters our timeline of life’s early evolution.

World-Today-News.com: You mentioned quinones. Can you elaborate on the role of these molecules in both photosynthesis and aerobic respiration, and how methyl-plastohydroquinone fits into this picture?

Dr. Reed: Quinones are essential electron carriers in both photosynthetic and respiratory processes. They exist in various forms, each adapted to specific environments and functions. Aerobic quinones, those that need oxygen, were known in two primary forms: one for photosynthesis and one for respiration. Methyl-plastohydroquinone is a third form, seemingly a ‘transitional’ form that bridges the gap. This molecule possesses characteristics common to both photosynthetic and respiratory quinones. It points to a much earlier development of the fundamental cellular tools to utilize oxygen, potentially setting the stage for the dramatic changes that took place during the Great Oxidation Event.

World-Today-News.com: This research hinges on the study of Nitrospirota, a nitrogen-utilizing bacteria. Why was this bacterium crucial to this discovery?

Dr. Reed: This is where the discovery’s brilliance lies. Investigating Nitrospirota, a seemingly unrelated bacteria, gave researchers an unexpected prospect. The unusual features of the quinone molecules found within the nitrogen-utilizing bacteria prompted close inspection, revealing an earlier link to an aspect of life that seemingly couldn’t exist. It’s a gorgeous illustration of the importance of unexpected findings: Frequently enough, research opens up entirely new understanding simply as of one scientist’s astute observation of an anomaly. We must always be observing anomalies!

World-Today-News.com: What are the practical implications of this research?

Dr. Reed: The implications extend across several fields.

Rethinking Evolutionary biology: The research necessitates a significant reassessment of the evolutionary timeline and interrelationships of various life forms.

understanding the Origin of Life: It offers crucial insights into the early conditions on Earth and the development of essential biological processes.

* Biotechnology and Medicine: A better understanding of quinone roles could potentially be harnessed in biotechnology and pharmaceutical applications. We could even unlock answers to new treatments by understanding this ancient molecular pathway.

The study of these ancient molecules teaches us about contemporary biological mechanisms, demonstrating that the past holds numerous clues to present and future understandings.

World-Today-News.com: What are the next steps in this research?

Dr. Reed: Many questions remain. We need to investigate the precise evolutionary pathways that led to the diversification of quinones, how methyl-plastohydroquinone functioned in early life forms, and the broader ecological implications of the early interplay between photosynthesis and aerobic respiration.

World-today-News.com: Thank you, dr. reed, for sharing these valuable insights. This discovery truly reshapes our understanding of the foundational processes of life on Earth.

Dr. Reed: My pleasure. It’s a thrilling time to be involved in this research. We’re only beginning to scratch the surface of this area of inquiry, and the possibilities are immense.

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