Rosa Rubicondior: Abiogenesis News - Closing Another of Creationism's God-Shaped Gaps

How life’s building blocks took shape on early Earth: the limits of membraneless polyester protocell formation – ELSI｜EARTH-LIFE SCIENCE INSTITUTE

Creationism’ ever-shrinking little god that sits in the abiogenesis gap, just got smaller with the news that researchers led by PhD student Mahendran Sithamparam of the Space Science Center (ANGKASA), Institute of Climate Change, National University of Malaysia, working at the Earth-Life Science Institute (ELSI) in the Institute of Science, Tokyo, Japan, have shown how primitive protocells could have formed under a wide range of realistic probiotic Earth conditions. The research team included scientists from Taiwan and China.

The research showed that membraneless protocells could have formed by polymerization of alpha-hydroxy acids (αHAs) to form polyester microdroplets, not to be confused with the modern plastic polyester. These polymers were polymers of esters - simple organic compounds which are chemically similar to the monomers that make modern polyester fibres.

Tell me all about micro polyester droplets as possible early protocells. Micro polyester droplets have recently been investigated as potential early protocells due to their ability to form spontaneously in prebiotic conditions and exhibit behaviours that mimic some cellular properties. Here’s a detailed breakdown:

What Are Micro Polyester Droplets?
Micro polyester droplets are tiny, membraneless liquid-like structures composed of polyester molecules. Polyesters are a class of polymers that can form via simple condensation reactions between hydroxy acids or polyhydroxy-polycarboxylic acids, which could have been abundant on early Earth.
Why Are They of Interest in Protocell Research?
The origin of life research has long been interested in how early protocells might have formed before the advent of phospholipid membranes. Traditional models include fatty acid vesicles, but recent studies suggest that polymer-based droplets, such as micro polyester droplets, could have played a role. They are particularly interesting because:

They **form spontaneously** under plausible prebiotic conditions.
They can **sequester biomolecules** like RNA and proteins, potentially aiding primitive metabolism.
They exhibit **phase separation**, which allows concentration and compartmentalization of biochemical reactions, a key prerequisite for cellular life.

Formation Under Prebiotic Conditions
Researchers have demonstrated that polyester droplets can form in environments mimicking early Earth. This could occur in:

Hydrothermal vents where temperature fluctuations drive condensation reactions.
Shallow pools with cycles of wet-dry conditions, which promote polymerization.
Areas rich in hydroxy acids, which could be produced abiotically via atmospheric or hydrothermal chemistry.

Chemical Properties and Stability

Polyester droplets are more **chemically robust** than lipid vesicles, which are sensitive to changes in pH and salinity.
They are **highly dynamic**, meaning they can fuse, divide, and change size—behaviours reminiscent of primitive cell-like compartments.
They can **absorb and concentrate organic molecules**, including amino acids and nucleotides, which could facilitate early biochemical evolution.

Relevance to the RNA World Hypothesis
A major challenge for the RNA world hypothesis is how RNA molecules could have been concentrated and protected from degradation. Micro polyester droplets provide a potential solution:

They can **selectively encapsulate RNA**, providing a stable environment for early replication.
They offer **compartmentalization**, a crucial step toward molecular evolution and the emergence of self-sustaining reactions.
Some studies suggest they could support **primitive metabolic cycles** by allowing localized chemical reactions.

Comparison to Other Protocell Models

Feature

Stability

Polyester Droplets: High

Fatty Acid Vesicles: Moderate

Coacervates: High

Formation Ease

Polyester Droplets: Simple polymerization

Fatty Acid Vesicles: Requires amphiphiles

Coacervates: Require charges polymers

RNA Compatibility

Polyester Droplets: High

Fatty Acids Vesicles: Moderate

Coacervates: High

Dynamic Behaviour

Polyester Droplets: Yes

Fatty Acid Vesicles: Limited

Coacervates: Yes

Enclosure of Molecules

Polyester Droplets: Strong

Fatty Acid Vesicles: Weak

Coacervates: Strong

Possible Pathways to True Cellular Life
If micro polyester droplets played a role in early life, they could have eventually given way to more complex protocells by:

Incorporating **primitive catalysts**, such as metal ions or ribozymes, to drive chemical reactions.
Developing **membrane-like structures**, either by merging with lipids or evolving into amphiphilic polymers.
Enabling **genetic material replication**, forming a link between compartmentalization and genetic evolution.

Challenges and Open Questions

How did these droplets transition into more complex cellular structures?
Could they catalyse reactions autonomously, or would additional molecules be needed?
Were polyester-based protocells widespread, or just one of many competing prebiotic compartments?

Conclusion
Micro polyester droplets present an exciting alternative or complement to traditional lipid-based protocell models. Their ability to encapsulate biomolecules, self-organize, and remain stable under a range of conditions makes them a strong candidate for early protocellular life. Further research into their chemical properties and evolutionary potential could provide deeper insights into life’s origins.

The research findings are published in the American Chemical Society journal ACS Bio & Med Chem Au and are explained in a news release from the Earth Life Science Institute, Tokyo:

How life’s building blocks took shape on early Earth: the limits of membraneless polyester protocell formation
New research reveals polyester microdroplets, proposed as model membraneless protocells, formed under a wide range of prebiotic conditions, suggesting these molecules were more widespread than previously thought.
One leading theory on the origins of life on Earth proposes that simple chemical molecules gradually became more complex, ultimately forming protocells—primitive, non-living structures that were precursors of modern cells. A promising candidate for protocells is polyester microdroplets, which form through the simple polymerisation of alpha-hydroxy acids (αHAs), compounds believed to have accumulated on early Earth possibly formed by lightning strikes or delivered via meteorites, into protocells, followed by simple rehydration in aqueous medium. A recent study from the Earth-Life Science Institute (ELSI) at Institute of Science Tokyo provides new evidence supporting the formation of polyester microdroplets under a wider range of realistic prebiotic conditions than previously thought.

Led by PhD student Mahendran Sithamparam of the Space Science Center (ANGKASA), Institute of Climate Change, National University of Malaysia as the first author and co-supervised by ELSI’s Specially Appointed Associate Professor Tony Z. Jia and ANGKASA Research Scientist Kuhan Chandru, the study explored the formation of these microdroplets under conditions more reflective of early Earth. The team found that polyester microdroplets could form even in salt-rich environments, at low αHA concentrations, and in small reaction volumes. This expands on previous research, which primarily considered their formation at high concentrations or in larger bodies of water such as coastal areas of lakes or hot springs. The findings suggest instead that polyester protocells were likely more widespread than previously thought, potentially forming in confined spaces like rock pores or even in high-salt environments such as briny pools or oceanic environments.

In 2019, the research team discovered that polyester microdroplets could form through a simple dehydration process. When gently heated to 80°C, phenyllactic acid (PA), a type of αHA, transitioned into a gel-like substance that subsequently formed membraneless droplets when rehydrated. In their latest study, the researchers investigated whether these microdroplets could form under more dilute or lower volume conditions, similar to those expected on prebiotic Earth.

Earlier laboratory tests often used high initial concentrations and volumes of αHAs in the hundreds-of-millimolar or microliter range, respectively, which may not reflect the conditions on prebiotic Earth, where such conditions were unlikely; this is why we needed to push the limits of the polymerisation droplet assembly processes to see whether assembly of such protocells would have actually been viable on early Earth.

Associate Professor Tony Z. Jia, co-corresponding author
Earth-Life Science Institute
Institute of Future Science
Institute of Science Tokyo, Japan.

To simulate these more realistic conditions, the researchers reduced the concentration and volume of PA in synthesis and subsequent droplet formation studies. They found that polyesters could be synthesised and droplets could form with as little as 500 µL of 1 mM PA or 5 µL of 500 mM PA. This suggests that polyester microdroplets could have naturally emerged both in confined spaces, such as rock pores, or dilute environments, such as those following flooding or precipitation.

To further test real-world conditions, the team simulated reactions in salinities resembling those in the ancient ocean. They introduced 1M NaCl, KCl, and MgCl2 to the PA reactants, finding that polyester synthesis and microdroplet assembly could proceed in NaCl and KCl but not in MgCl2. This suggests that polyester microdroplets would have been more likely to form in water bodies with specific salt compositions, such as those high in NaCl and KCl but low in MgCl2, favourable to αHA polymerisation and subsequent polyester microdroplet assembly.

The conclusions of this study clearly show that polyester protocells were likely more common on early Earth than previously thought and also informs the next generation of laboratory studies of the system. Thus, a wide range of primitive environments—including oceanic, freshwater, briny, and confined spaces like rock pores—could have ultimately supported the formation of these protocells both on Earth or elsewhere.

Kuhan Chandru, Co-corresponding author
Space Science Center (ANGKASA)
Institute of Climate Change
National University of Malaysia, Selangor, Malaysia.

This research was made possible through the ELSI Visitor Program, which fosters international collaboration involving ELSI researchers; this program supported Sithamparam on two separate visits to ELSI in 2023, as well as a visit during summer 2023 to ELSI for graduate student Ming-Jing He (National Central University) to complete experiments for her master’s thesis. All experiments were conducted at ELSI, and the findings are featured in the ACS Bio & Med Chem Au Special Issue, 2024 Rising Stars in Biological, Medicinal, and Pharmaceutical Chemistry, of which Jia is an awardee.

Reference

Mahendran Sithamparam¹, Rehana Afrin², Navaniswaran Tharumen¹, Ming-Jing He³, Chen Chen⁴, Ruiqin Yi⁵, Po-Hsiang Wang^3,6, Tony Z. Jia^2,7*, and Kuhan Chandru^1,8,9*
Probing the Limits of Reactant Concentration and Volume in Primitive Polyphenyllactate Synthesis and Microdroplet Assembly Processes ACS Bio & Med Chem Au DOI: 10.1021/acsbiomedchemau.4c00082

Space Science Center (ANGKASA), Institute of Climate Change, National University of Malaysia, Selangor 43650, Malaysia
Earth-Life Science Institute, Institute of Future Science, Institute of Science Tokyo, 2-12-1-IE-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
Department of Chemical Engineering and Materials Engineering, National Central University, No. 300, Zhongda Rd., Zhongli District, Taoyuan 32001, Taiwan (R.O.C.)
Biofunctional Catalyst Research Team, RIKEN Center for Sustainable Resource Science (CSRS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
State Key Laboratory of Isotope Geochemistry and CAS Center for Excellence in Deep Earth Science, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
Graduate Institute of Environmental Engineering, National Central University, No. 300, Zhongda Road, Zhongli District, Taoyuan City 320, Taiwan
Blue Marble Space Institute of Science, 600 first Ave, Floor 1, Seattle, Washington 98104, United States
Polymer Research Center (PORCE), Faculty of Science and Technology, National University of Malaysia, Selangor 43600 Malaysia
Institute of Physical Chemistry, CENIDE, University of Duisburg-Essen, 45141 Essen, Germany
*Corresponding authors’ email: tzjia@elsi.jp (Tony Z. Jia) and kuhan@ukm.edu.my (Kuhan Chandru)

Abstract

Polyester microdroplets have been investigated as primitive protocell models that can exhibit relevant primitive functions such as biomolecule segregation, coalescence, and salt uptake. Such microdroplets assemble after dehydration synthesis of alpha-hydroxy acid (αHA) monomers, commonly available on early Earth, via heating at mild temperatures, followed by rehydration in aqueous media. αHAs, in particular, are also ubiquitous in biology, participating in a variety of biochemical processes such as metabolism, suggesting the possible strong link between primitive and modern αHA-based processes. Although some primitive αHA polymerization conditions have been probed previously, including monomer chirality and reaction temperature, relevant factors pertaining to early Earth’s local environmental conditions that would likely affect primitive αHA polymerization are yet to be fully investigated. Hence, probing the entire breadth of possible conditions that could promote primitive αHA polymerization is required to understand the plausibility of polyester microdroplet assembly on early Earth at the origin of life. In particular, there are numerous aqueous environments available on early Earth that could have resulted in varying volumes and concentrations of αHA accumulation, which would have affected subsequent αHA polymerization reactions. Similarly, there were likely varying levels of salt in the various aqueous prebiotic solutions, such as in the ocean, lakes, and small pools, that may have affected primitive reactions. Here, we probe the limits of the dehydration synthesis and subsequent membraneless microdroplet (MMD) assembly of phenyllactic acid (PA), a well-studied αHA relevant to both biology and prebiotic chemistry, with respect to reactant concentration and volume and salinity through mass spectrometry- and microscopy-based observations. Our study showed that polymerization and subsequent microdroplet assembly of PA appear robust even at low reactant concentrations, smaller volumes, and higher salinities than those previously tested. This indicates that PA-polyester and its microdroplets are very much viable under a wide variety of conditions, thus more likely participating in prebiotic chemistries at the origins of life.

Sithamparam, Mahendran; Afrin, Rehana; Tharumen, Navaniswaran; He, Ming-Jing; Chen, Chen; Yi, Ruiqin; Wang, Po-Hsiang; Jia, Tony Z.; Chandru, Kuhan
Probing the Limits of Reactant Concentration and Volume in Primitive Polyphenyllactate Synthesis and Microdroplet Assembly Processes ACS Bio & Med Chem Au; doi: 10.1021/acsbiomedchemau.4c00082.

Copyright: © 2025 The authors.
Published by American Chemical Society. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)

In addition, the first two paragraphs of the team's introduction to their paper should make grim reading for any creationist still deluded enough to believe the absurd nonsense that biomedical scientists are giving up on the Theory of Evolution and instead turning to magical creationism for answers:

Introduction
Abiogenesis describes the chemical evolution of life on early Earth, i.e., the origins of life (OoL), and involves the formation of simple organic molecules, their polymerization and self-assembly into complex molecules, the emergence of protocells, (1−3) and the development of robust Darwinian evolution before or at the onset of the last universal common ancestor (LUCA). (4) In particular, the synthesis of the primitive chemicals potentially leading to life could have taken place in various settings or by various geological processes on early Earth, including Miller–Urey chemistry, (5) hydrothermal vents, (6,7) shallow pools and lakes, (8,9) panspermia delivery, (10) or wet–dry cycles, (11,12) just to name a few, and likely facilitated possible pathways toward several OoL hypotheses, i.e., the lipid-first world, (13) the metabolism-first world, (14) the RNA world, (15) etc. These primitive environments or processes, combined with energy (i.e., lightning strikes; (16) light, UV-rays, and heat from the young sun; (17) energy from radioactive elements; (18) ionizing radiation; (19) etc.) could have facilitated the formation of many simple biomolecules on early Earth such as amino acids, (20) lipids, (21) nucleotides, (22) simple sugars, (23) or even phosphorus-containing compounds, (24) which could have exhibited important functions or contributions to possibly kick-start the OoL.

However, it is important to recognize that the OoL is not necessarily strictly bound to the canonical biomolecules (i.e., lipids, amino acids, etc.). Other prebiotically available organic molecules could have also played equally essential roles during the emergence of life. (25,26) In particular, we speculate that the properties of α-hydroxy acids (αHAs) lead this category of molecules to be potential key compounds at the OoL due to their active participation of αHAs in chemistries ranging from the prebiotic world all the way to modern biology. For example, citric acid (CA) and malic acid, both αHAs, serve as intermediates in the Krebs cycle. (27−29) Ribosomes, traditionally known for synthesizing proteins, have also been shown to polymerize various αHAs, including lactic acid (LA) and phenyllactic acid (PA), into polyesters, a process that can be directed by mRNA through genetic-code reprogramming. (30) Apart from αHA involvement in biology, αHAs are also essential in biotechnology and biomedicine. (31−38)

Far from being impossible like creationists claim, although they can never explain which laws of chemistry and/or physics makes it so. it seems there are a growing number of ways in which self-replicating systems that evolved into complex cells could have arisen on pre-biotic Earth. Of course, there is no reason to suppose at the pre-DNA stage, that there was only one type of protocell produced by just one set of conditions. There is no reason two or more could not have arisen then either joined forces in symbiosis or one emerged the winner in a competition for resources.

But however it happened, it clearly did not need an unexplained magician suspending the laws of chemistry and physics and making them do thing they couldn't do on their own.

Stand by for the imminent eviction of creationism's little shrinking god from one of its few remaining refuges, as science closes yet another gap where gods used to live in more primitive and unenlightened times.

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