Scientists at Newcastle University, with support from the Natural Environment Research Council, have been investigating the mystery of how life began on Earth more than 3.5 billion years ago.
They studied the transformation of inert geological materials into the first living systems. Their experiments combined hydrogen, bicarbonate, and iron-rich magnetite under conditions similar to mild hydrothermal vents. This process produced a variety of organic molecules, including fatty acids with up to 18 carbon atoms, among others.
It was published in the magazine Communication Earth and EnvironmentTheir findings could reveal how some of the key molecules needed to create life are made from inorganic chemicals. This is essential for understanding key steps in how life formed on Earth billions of years ago. Their results may provide a plausible origin for the organic molecules forming ancient cell membranes, perhaps selectively selected by early biochemical processes on early Earth.
Fatty acids in the early stages of life
Fatty acids are long organic molecules with water-attracting and water-repelling regions that naturally automatically form cell-like compartments in water. It is this type of molecule that created the first cell membranes. However, despite their importance, it was unclear where these fatty acids came from during the early stages of life. One idea is that they did not form in hydrothermal vents, where carbon dioxide-laden seawater mixed with hydrothermal water mixed with hydrogen-rich fluids coming out of underwater vents. That’s what it is.2.
The research group recreated in the laboratory key aspects of the chemical environment found in early Earth’s oceans and the mixing of hot alkaline water from around certain types of hydrothermal vents. They found that in the presence of iron-based minerals that were present on early Earth, when hot hydrogen-rich fluids were mixed with carbon dioxide-rich water, they formed the necessary molecules to form primitive cell membranes. discovered that different types of molecules are produced.
Lead author Dr Graham Purvis carried out the study at Newcastle University and is currently a postdoctoral fellow at Durham University.
“Central to the beginning of life are cellular compartments, which are critical for isolating internal chemicals from the external environment. These compartments facilitate life-sustaining reactions by concentrating chemicals and facilitating energy production. and potentially served as the basis for the earliest moments of life.
This result suggests that the concentration of hydrogen-rich fluids and bicarbonate-rich water from alkaline hydrothermal vents on iron-based minerals precipitated the rudimentary membranes of early cells at the beginning of life. It suggests that there is a sex. This process may have given rise to a wide variety of membrane types, some of which may have served as cradles for life when it began. In addition, this process of transformation may have contributed to the formation of certain acids present in the elemental composition of the meteorite. ”
Dr John Telling, principal investigator and leader in biogeochemistry in the School of Natural and Environmental Sciences, added:
“We believe this research has the potential to provide a first step into how life originated on Earth. Our lab is currently working on a second important step. Research continues to determine how these organic molecules, which are initially ‘stuck’ to the mineral surface, detach to form cell-like compartments surrounded by spherical membranes. . The first potential “protocells” that were to form the first cellular life. ”
Interestingly, the researchers also suggest that similar film-forming reactions may be occurring today in the subsurface oceans of the solar system’s icy moons. This raises the possibility that other origins of life exist on these distant worlds.
Reference: “Long-chain fatty acid production by hydrogen-driven bicarbonate reduction in ancient alkaline hydrothermal vents” Graham Purvis, Lidija Šiller, Archie Crosskey, authors Jupiter Vincent, Corinne Wills, Jake Sherif, Siho Xavier, John Telling, January 10, 2024, Communication Earth and Environment.
DOI: 10.1038/s43247-023-01196-4
This research was funded by the Natural Environment Research Council.