Nav: Home

Origin of life: The importance of interfaces

July 29, 2019

Tiny gas-filled bubbles in the porous rock found around hot springs are thought to have played an important role in the origin of life. Temperature differences at the interface between liquid phases could therefore have initiated prebiotic chemical evolution.

A plethora of physicochemical processes must have created the conditions that enabled living systems to emerge on the early Earth. In other words, the era of biological evolution must have been preceded by a - presumably protracted - phase of 'prebiotic' chemical evolution, during which the first informational molecules capable of replicating themselves were assembled and selected. This scenario immediately raises another question: Under what environmental conditions could prebiotic evolution have taken place? One possible setting has long been discussed and explored - tiny pores in volcanic rocks. An international team of researchers led by Dieter Braun (Professor of Systems Biophysics at Ludwig-Maximilians-Universitaet (LMU) in Munich) has now taken a closer look at the water-air interfaces in these pores. They form spontaneously at gas-filled bubbles and show an interesting combination of effects.

They found that they could have played an important part in facilitating the physicochemical interactions that contributed to the origin of life. Specifically, Braun and his colleagues asked whether such interfaces could have stimulated the kinds of chemical reactions that triggered the initial stages of prebiotic chemical evolution. Their findings appear in the leading journal Nature Chemistry.

The study strongly supports the notion that tiny gas-filled bubbles that were trapped in, and reacted with, the surfaces of pores in volcanic rocks could indeed have accelerated the formation of the chemical networks that ultimately gave rise to the first cells. Thus, the authors were able to experimentally verify and characterize the facilitating effects of air-water interfaces on the relevant chemical reactions. If there is a difference in temperature along the surface of such a bubble, water will tend to evaporate on the warmer side and condense on the cooler side, just as a raindrop that lands on a window runs down the flat surface of the glass and eventually evaporates. "In principle, this process can be repeated ad infinitum, since the water continuously cycles between the gaseous and the liquid phase," says Braun, who has characterized the mechanism and the underlying physical processes in detail, together with his doctoral student Matthias Morasch and other members of his research group. The upshot of this cyclical phenomenon is that molecules accumulate to very high concentrations on the warmer side of the bubble.

"We began by making a series of measurements of reaction rates under various conditions, in order to characterize the nature of the underlying mechanism," says Morasch. The phenomenon turned out to be surprisingly effect and robust. Even small molecules could be concentrated to high levels. "We then tested a whole range of physical and chemical processes, which must have played a central role in the origin of life - and all of them were markedly accelerated or made possible at all under the conditions prevailing at the air-water interface." The study benefitted from interactions between Braun's group of biophysicists and the specialists in disciplines such as chemistry and geology who work together with him in the Collaborative Research Centre (SFB/TRR) on the Origin of Life (which is funded by the DFG), and from cooperations with members of international teams.

For example, the LMU researchers show that physicochemical processes which promote the formation of polymers are either stimulated - or made possible in the first place - by the availability of an interface between the aqueous environment and the gas phase, which markedly enhances rates of chemical reactions and catalytic mechanisms. In fact, in such experiments, molecules could be accumulated to high concentrations within lipid membranes when the researchers added the appropriate chemical constituents. "The vesicles produced in this way are not perfect. But the finding nevertheless suggests how the first rudimentary protocells and their outer membranes might have been formed," says Morasch.

Whether or not this sort of process can take place in such vesicles "does not depend on the nature of the gas within the bubble. What is important is that, owing to differences in temperature, the water can evaporate in one location and condense in another," Braun explains. In earlier work, his group has already described a different mechanism by which temperature differences in water bodies can serve to concentrate molecules. "Our explanatory model enables both effects to be combined, which would enhance the concentrating effect and thus increase the efficiency of prebiotic processes," he adds.
-end-


Ludwig-Maximilians-Universität München

Related Science Articles:

75 science societies urge the education department to base Title IX sexual harassment regulations on evidence and science
The American Educational Research Association (AERA) and the American Association for the Advancement of Science (AAAS) today led 75 scientific societies in submitting comments on the US Department of Education's proposed changes to Title IX regulations.
Science/Science Careers' survey ranks top biotech, biopharma, and pharma employers
The Science and Science Careers' 2018 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.
Science in the palm of your hand: How citizen science transforms passive learners
Citizen science projects can engage even children who previously were not interested in science.
Applied science may yield more translational research publications than basic science
While translational research can happen at any stage of the research process, a recent investigation of behavioral and social science research awards granted by the NIH between 2008 and 2014 revealed that applied science yielded a higher volume of translational research publications than basic science, according to a study published May 9, 2018 in the open-access journal PLOS ONE by Xueying Han from the Science and Technology Policy Institute, USA, and colleagues.
Prominent academics, including Salk's Thomas Albright, call for more science in forensic science
Six scientists who recently served on the National Commission on Forensic Science are calling on the scientific community at large to advocate for increased research and financial support of forensic science as well as the introduction of empirical testing requirements to ensure the validity of outcomes.
World Science Forum 2017 Jordan issues Science for Peace Declaration
On behalf of the coordinating organizations responsible for delivering the World Science Forum Jordan, the concluding Science for Peace Declaration issued at the Dead Sea represents a global call for action to science and society to build a future that promises greater equality, security and opportunity for all, and in which science plays an increasingly prominent role as an enabler of fair and sustainable development.
PETA science group promotes animal-free science at society of toxicology conference
The PETA International Science Consortium Ltd. is presenting two posters on animal-free methods for testing inhalation toxicity at the 56th annual Society of Toxicology (SOT) meeting March 12 to 16, 2017, in Baltimore, Maryland.
Citizen Science in the Digital Age: Rhetoric, Science and Public Engagement
James Wynn's timely investigation highlights scientific studies grounded in publicly gathered data and probes the rhetoric these studies employ.
Science/Science Careers' survey ranks top biotech, pharma, and biopharma employers
The Science and Science Careers' 2016 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.
Three natural science professors win TJ Park Science Fellowship
Professor Jung-Min Kee (Department of Chemistry, UNIST), Professor Kyudong Choi (Department of Mathematical Sciences, UNIST), and Professor Kwanpyo Kim (Department of Physics, UNIST) are the recipients of the Cheong-Am (TJ Park) Science Fellowship of the year 2016.
More Science News and Science Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.