Were large soda lakes the cradle of life?
Along with nitrogen and carbon, phosphorus is an essential element for life on Earth. It is a central component of molecules such as DNA and RNA, which serve to transmit and store genetic information, and ATP (adenosine triphosphate), which cells need to produce energy.
Phosphorus may also have played a key role in the origin of life. Certain conditions are needed to trigger the start of the biochemical processes that precede life. One of these is the presence of sufficient phosphorus. Its availability regulates the growth and activities of organisms. Unlike nitrogen or carbon, however, phosphorus is relatively rare at Earth's surface – which was the case in the era before life existed as well as today.
It is precisely because phosphorus is rare and so difficult to obtain, yet subject to high demand by living organisms, that scientists have long wondered how life could have arisen at all.
To answer this question, they conducted experiments in the laboratory. These showed that prebiotic chemistry requires very high concentrations of phosphorus – about 10,000 times more phosphorus than naturally occurs in water. This raises the question of how and where such high concentrations of phosphorus in water occurred on Earth billions of years ago.
Earth scientist Craig Walton has a new answer: large soda lakes without natural runoff could maintain phosphorus concentrations for a sufficiently long time, even if life begins to exist in them at some point (and continuously consumes phosphorus). The results of the study have just been published in the journal Science Advances.
Such lakes lose water only through evaporation. This means that phosphorus is left in the water instead of being washed away through rivers and streams. As a result, very high concentrations of phosphorus can build up in these soda lakes.
As early as 2020, researchers from the University of Washington had suggested that soda lakes could be the cradle of life. Walton has now taken this further. The researcher is investigating questions about the origin of life from a geochemical perspective as part of a Nomis fellowship at ETH Zurich’s Centre for Origin and Prevalence of Life (COPL).
Not every soda lake is suitable; Walton excludes small ones. “As soon as life develops in them, their phosphorus supply would be depleted faster than it is replenished. This would nip in the bud both the chemical reactions and the developing life,” says Walton. In large soda lakes, on the other hand, the phosphorus concentrations are high enough to sustain both the basic chemical reactions and life over the long term. These high concentrations are achieved through a high volume of inflowing river water, which contains phosphorus, while water only leaves the lake through evaporation. Since phosphorus does not evaporate easily, it stays behind and accumulates in the lake.
One example of such a large soda lake is Mono Lake in California. It is about twice the size of Lake Zurich. In Mono Lake, the phosphorus concentration remains constantly high, allowing a wide variety of organisms to flourish. This is crucial because in small lakes, the phosphorus is used up before new amounts can be formed. Phosphorus in Mono Lake is therefore maintained at a high concentration, which means that a lot of phosphorus regularly flows in without the phosphorus content dropping too quickly.
Walton and his team therefore consider large soda lakes that had a constant high phosphorus supply in the early history of the Earth to have been an ideal environment for the origin of life. The researchers assume that life is more likely to have originated in such large bodies of water than in small pools, as Charles Darwin had suspected.
The origin of life could therefore be closely linked to the special environment of large soda lakes, which, due to their geological setting and phosphorus balance, provided ideal conditions for prebiotic chemistry. “This new theory helps to solve another piece of the puzzle of the origin of life on Earth,” says Walton.
Journal
Science Advances
Subject of Research
Not applicable
Article Title
Large closed-basin lakes sustainably supplied phosphate during the origins of life
How calcium may have unlocked the origins of life’s molecular asymmetry
Research hints at calcium’s potential role in enforcing a specific molecular handedness among primitive polyesters and early biomolecules
image:
Calcium tartrate crystals can coexist with tartrate-containing polyester microdroplets, suggesting the potential for dynamic phase transitions of tartrates or tartrate-containing molecules on early Earth.
view moreCredit: Chen Chen
A new study led by researchers at the Earth-Life Science Institute (ELSI) at Institute of Science Tokyo has uncovered a surprising role for calcium in shaping life’s earliest molecular structures. Their findings suggest that calcium ions can selectively influence how primitive polymers form, shedding light on a long-standing mystery: how life’s molecules came to prefer a single “handedness” (chirality).
Like our left and right hands, many molecules exist in two mirror-image forms. Yet life on Earth has a striking preference: DNA’s sugars are right-handed, while proteins are built from left-handed amino acids. This phenomenon, called homochirality, is essential for life as we know it—but how it first emerged remains a major puzzle in origins of life research.
The team investigated tartaric acid (TA), a simple molecule with two chiral centers, to explore how early Earth’s environment might have influenced the formation of homochiral polymers. They discovered that calcium dramatically alters how TA molecules link together. Without calcium, pure left- or right-handed TA readily polymerises into polyesters, but mixtures containing equal amounts of both forms fail to form polymers readily. However, in the presence of calcium, this pattern reverses—calcium slows down the polymerisation of pure TA while enabling mixed solutions to polymerise.
“This suggests that calcium availability could have created environments on early Earth where homochiral polymers were favoured or disfavoured,” says Chen Chen, Special Postdoctoral Researcher at RIKEN Center for Sustainable Resource Science (CSRS), who co-led the study. The researchers propose that calcium drives this effect through two mechanisms: first, by binding with TA to form calcium tartrate crystals, which selectively remove equal amounts of both left- and right-handed molecules from the solution; and second, by altering the polymerisation chemistry of the remaining TA molecules. This process could have amplified small imbalances in chirality, ultimately leading to the uniform handedness seen in modern biomolecules.
What makes this study especially intriguing is its suggestion that polyesters—simple polymers formed from molecules like tartaric acid—could have been among life’s earliest homochiral molecules, even before RNA, DNA, or proteins. “The origin of life is often discussed in terms of biomolecules like nucleic acids and amino acids,” ELSI’s Specially Appointed Associate Professor Tony Z. Jia, who co-led the study, explains. “However, our work introduces an alternative perspective: that ‘non-biomolecules’ like polyesters may have played a critical role in the earliest steps toward life.”
The findings also highlight how different environments on early Earth could have influenced which types of polymers formed. Calcium-poor settings, such as some lakes or ponds, may have promoted homochiral polymers, while calcium-rich environments might have favoured mixed-chirality polymers.
Beyond chemistry, this research bridges multiple scientific fields—biophysics, geology, and materials science—to explore how simple molecules interacted in dynamic prebiotic environments. The study is also the result of years of interdisciplinary collaboration, bringing together researchers from seven countries across Asia, Europe, Australia, and North America.
“We faced significant challenges in integrating all of the complex chemical, biophysical, and physical analyses in a clear and logical way,” says project co-leader Ruiqin Yi of the Guangzhou Institute of Geochemistry, Chinese Academy of Sciences. “But thanks to the hard work and dedication of our team, we’ve uncovered a compelling new piece of the origins of life puzzle.” This research not only deepens our understanding of life’s beginnings on Earth but also suggests that similar processes could be at play on other planets, helping scientists search for life beyond our world.
EDITOR’S NOTE:
Since the submission of the paper, the name of the university has changed from Tokyo Institute of Technology to Institute of Science Tokyo.
Co-author Chen Chen acquired most of the data during his period as a researcher at ELSI.
Reference
Chen Chena,1, Ruiqin Yib,1, Motoko Igisuc, Rehana Afrina, Mahendran Sithamparamd, Kuhan Chandrud,e,f, Yuichiro Uenoa,c,g, Linhao Sunh, Tommaso Laurenzii, Ivano Eberinii, Tommaso P. Fracciai, Anna Wangj,k,l,m, H. James Cleaves IIn,o, Tony Z. Jiaa,o,1, Primitive homochiral polyester formation driven by tartaric acid and calcium availability, Proceedings of the National Academy of Sciences (PNAS), DOI: 10.1073/pnas.2419554122
a. Earth-Life Science Institute (ELSI), Tokyo Institute of Technology, 2-12-IE-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
b. State Key Laboratory of Deep Earth Processes and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 9 Guangzhou, 510640, China
c. Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, 237-0061, Japan
d. Space Science Center (ANGKASA), Institute of Climate Change, National University of Malaysia (UKM), Bangi, Selangor 43650, Malaysia
e. Polymer Research Center (PORCE), Faculty of Science and Technology, National University of Malaysia, Selangor, 43600 Malaysia
f. Institute of Physical Chemistry, CENIDE, University of Duisburg-Essen, 45141 Essen, Germany
g. Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-IE-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
h. WPI Nano Life Science (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
i. Dipartimento di Scienze Farmacologiche e Biomolecolari“Rodolfo Paoletti”, Università degli Studi di Milano, 20133, Milano, Italy
j. School of Chemistry, UNSW Sydney, Sydney, NSW 2052, Australia
k. Australian Center for Astrobiology, UNSW Sydney, Sydney, NSW 2052, Australia
l. RNA Institute, UNSW Sydney, Sydney, NSW 2052, Australia
m. ARC Centre of Excellence for Synthetic Biology, UNSW Sydney, Sydney, NSW 2052, Australia
n. Department of Chemistry, Howard University, Washington, District of Columbia 20059, USA
o. Blue Marble Space Institute of Science, 600 1st Ave, Floor 1, Seattle, WA 98104, USA
More information
Institute of Science Tokyo (Science Tokyo) was established on October 1, 2024, following the merger between Tokyo Medical and Dental University (TMDU) and Tokyo Institute of Technology (Tokyo Tech), with the mission of “Advancing science and human wellbeing to create value for and with society.”
The Earth-Life Science Institute (ELSI) is one of Japan’s ambitious World Premiere International research centers, whose aim is to achieve progress in broadly inter-disciplinary scientific areas by inspiring the world’s greatest minds to come to Japan and collaborate on the most challenging scientific problems. ELSI’s primary aim is to address the origin and co-evolution of the Earth and life.
The World Premier International Research Center Initiative (WPI) was launched in 2007 by Japan’s Ministry of Education, Culture, Sports, Science and Technology (MEXT) to foster globally visible research centers boasting the highest standards and outstanding research environments. Numbering more than a dozen and operating at institutions throughout the country, these centers are given a high degree of autonomy, allowing them to engage in innovative modes of management and research. The program is administered by the Japan Society for the Promotion of Science (JSPS).
Polarisation microscopy analyses reveal that tartrate in the calcium tartrate crystals had no chirality preference.
Credit
Chen Chen
Journal
Proceedings of the National Academy of Sciences
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
Primitive homochiral polyester formation driven by tartaric acid and calcium availability
Article Publication Date
21-Mar-2025
