Life on Earth may have been incubated in seafloor vents

A recent study explored the chemical reactions underway in hydrothermal vents and explored the question of whether life on Earth may have begun there. Using computer simulations they tested possible scenarios and the answers they found could have implications for not only life on this planet, but possibly elsewhere in the universe. As an added bonus, their work may provide solutions to humanities long term energy needs and the problem of excess greenhouse gasses in the atmosphere.

Most people, most of the time, don’t think much about undersea vents. It is ‘only’ a place where excess heat from beneath the Earth’s surface escapes. However, those vents create unique chemical interactions and the fact that they exist at all are a fairly recent discovery.

“In 1977, scientists diving in the submersible Alvin made a stunning discovery on the bottom of the Pacific Ocean: vents pouring hot, mineral-rich fluids from beneath the seafloor. In addition, they also found the vents were inhabited by previously unknown organisms that thrived in the absence of sunlight. These discoveries forever changed our understanding of Earth and life on it,” reads the introductory page on the subject at the Woods Hole Oceanographic Institute web site.

According to chemists at the University College London (UCL), the vents could have spontaneously produced the molecules required for life. According to their research, the rock surfaces in the vents contain mineral particles similar to enzymes. Enzymes are molecules that cause chemical reactions inside living organisms, such as breaking food down into the components that give the body energy. This means that the minerals were able to turn the CO2 in water into carbon-based molecules such as formic acid and methanol.

That means that some of the basic building blocks of life were being created deep beneath the sea before life on Earth began. It is possible that this basic organic chemistry could have generated some of the first, very basic, life forms.

“There is a lot of speculation that hydrothermal vents could be the location where life on Earth began. There is a lot of CO2 dissolved in the water, which could provide the carbon that the chemistry of living organisms is based on, and there is plenty of energy, because the water is hot and turbulent. What our research proves is that these vents also have the chemical properties that encourage these molecules to recombine into molecules usually associated with living organisms,” said Nora de Leeuw, leader of the research team in a statement.

The researchers combined laboratory experiments with simulations run on UCL’s Legion supercomputer and the UK national supercomputing service HECToR in an attempt to recreate the conditions under which minerals would convert CO2 into organic molecules.

The experiments provided a “molecule-by-molecule view” of the interactions of the mineral greigite (Fe3S4) and CO2.

“We found that the surfaces and crystal structures inside these vents act as catalysts, encouraging chemical changes in the material that settles on them. They behave much like enzymes do in living organisms, breaking down the bonds between carbon and oxygen atoms. This lets them combine with water to produce formic acid, acetic acid, methanol and pyruvic acid. Once you have simple carbon-based chemicals such as these, it opens the door to more complex carbon-based chemistry,” said Nathan Hollingsworth, a co-author of the paper published in the journal Chemical Communications.

It has previously been theorized that carbon-based chemistry led to self-replicating molecules, which in turn led to the first single celled life forms, launching the multi-billion year process of evolution that got us to where we are today.

This research demonstrates that those first molecules can be created in nature without living organisms being present or introduced from elsewhere. Because we already know that life on Earth began in the oceans, the research suggests that hydrothermal vents were a very likely location for that process to have begun.

The research also demonstrates that carbon-based chemicals can be made from CO2 without extreme-heat or pressure. This means that it is possible to turn some of the excess CO2 that is currently causing climate change into fuel, fertilizer and plastic; ironically making greenhouse gasses one of the fuels of the future.

Finally the research could provide clues as to what other places in the universe might be capable of producing the kind of organic chemistry which leads to life. For example, a study published in the March 12 edition of the journal Nature shows that Saturn’s small, icy moon Enceladus appears to have hydrothermal activity going on deep beneath its frozen surface.

Be social, please share!