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Chasing Synthetic Life: A Tale of Forms, Chemical Fossils, and Biomorphs

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This Essay focuses briefly on early studies elaborated by natural and chemical philosophers, and the once‐called synthetic biologists, who postulated the transition from inanimate to animate matter and even foresaw the possibility of creating artificial life on the basis of physical and chemical principles only. Such ideas and speculations, ranging from soundness to weirdness, paved however the way to current developments in areas like abiotic pattern formation, cell compartmentalization, biomineralization, or the origin of life itself. In particular, the generation of biomorphs and their relationship to microfossils represents an active research domain and seems to be the logical way to bring the historical work up to the future, as some scientists are trying to make artificial cells. The last sections of this essay will also highlight modern science aimed at understanding what life is and, whether or not, it can be redefined in chemical terms.
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German Edition:DOI:10.1002/ange.201915853
History of Science International Edition:DOI:10.1002/anie.201915853
Chasing Synthetic Life:ATale of Forms,Chemical
Fossils,and Biomorphs
Pedro Cintas*
Keywords: artificial life ·biomorphs ·
chemical fossils ·morphogenesis ·origins of life
Abstract: This Essay focuses briefly on early studies elabo-
rated by natural and chemical philosophers,and the once-
called synthetic biologists,who postulated the transition from
inanimate to animate matter and even foresaw the possibility of
creating artificial life on the basis of physical and chemical
principles only.Such ideas and speculations,ranging from
soundness to weirdness,paved however the way to current
developments in areas like abiotic pattern formation, cell
compartmentalization, biomineralization, or the origin of life
itself.Inparticular,the generation of biomorphs and their
relationship to microfossils represents an active research
domain and seems to be the logical way to bring the historical
work up to the future,assome scientists are trying to make
artificial cells.The last sections of this essay will also highlight
modern science aimed at understanding what life is and,
whether or not, it can be redefined in chemical terms.
1. Introduction
Thesearch for the origin of life represents afascinating
subject aimed at understanding how primeval biomolecules
formed from available precursors on Earth and beyond,[1, 2]
then assembled into macro- and supramolecular oligomers of
increasing hierarchical organization,[3] which led ultimately to
complex patterns and structures that hosted the primitive
forms of life.[4]
Chemists are now capable of synthesizing complex
structures under abiotic conditions that feature two essential
ingredients of living systems,that is,self-organization and
self-replication. One key concluding remark is that compli-
cated forms and patterns can be created with spatial order
with the assistance of simple physical forces.Itisclear,
however, that life as we know it is more than structured
matter that could conceal life beneath. Yet, this research not
only imitates natural systems but also attempts to provide
aclue for fossil-like structures and primitive organisms.In
doing so,wecould make sense of life from scratch and
advancing in our understanding and fabrication of the
artificial cell, ultimately the synthetic cell.[5] Modern biolo-
gists and geneticists are now shaping this new,cutting-edge
front they call synthetic biology.Assurprising as it may be,
the notion of “synthetic biology” was actually coined in the
19th century,inaperiod where the advent of science took
observation as its sacred hallmark, also struggling against
obscure tenets and theories.[6] Such scientists pursued the
same goals,adorned with atouch of naivety and romanticism,
to artificially create structures that come alive to do things
that natural organisms can. In short, they wanted to know
what life is.The first part of this Essay traces this historical
context through some protagonists,recreating both science
and anti-science,with afocus on morphogenesis and the
search for the synthesis of life.[7] Later on, we shall see how the
early work has influenced modern theories on the formation
of fossils and biominerals and, how “biomorphs” have much
to do with arational design of biomimetic structures and
artificial cell machinery.
2. From Gardens to Bioalchemy
If one may propel the reader on an entertaining journey of
artificially created biomimetic structures,the toehold could
be the so-called chemical/crystal garden generated exclusively
from inorganic materials and first described by German-
Dutch alchemist and apothecary Johann Rudolf Glauber in
1646.[8] Born in Karlstadt in 1604, Glauber lived in various
European cities and settled finally in Amsterdam where he
died in 1668 or 1670. He became known as the German Boyle
and was likely the first alchemist to live from the activities of
this trade as chemical producer, especially by supplying
hydrated sodium sulfate (GlauberQssalt), used as mild
laxative for centuries.Glauber obtained the original chemical
garden by putting iron(II) chloride crystals into asolution of
water glass (K2SiO3,potassium silicate). We know well the
science behind this,which has become an instructive part of
freshman courses.Ametal salt, usually the chloride,starts to
dissolve in water and then forms an insoluble metal silicate by
anion metathesis.The metal silicate constitutes asemiperme-
able membrane and, because the ionic strength of the metal
solution inside is greater than that of the bulk solution of
sodium or potassium silicate,osmotic pressure causes the
[*] Prof. Dr.P.Cintas
Dpto. Qu&mica Org#nica eInorg#nica, Facultad de Ciencias,
UniversidaddeExtremadura
06006 Badajoz (Spain)
E-mail:pecintas@unex.es
The ORCID identificationnumber(s) for the author(s) of this article
can be found under:
https://doi.org/10.1002/anie.201915853.
A
ngewandte
Chemie
Essays
7296 T2020 Wiley-VCH Verlag GmbH &Co. KGaA,Weinheim Angew.Chem. Int. Ed. 2020,59,7296–7304
... Silica gels and chert deposits from soda lakes, particularly Lake Magadi (Kenya), were proposed as typical models for explaining the origins and mechanisms of the chert deposits and the preservation of cellular structures in siliceous -7 -sediments in Precambrian environments (Eugster, 1967(Eugster, , 1969Eugster and Jones, 1968;Hay, 1968;Schubel and Simonson, 1990;Behr and Röhricht, 2000;Behr, 2002;Reinhardt et al., 2019;Leet et al., 2021). Identification of these cellular structures and fossils in the Precambrian Earth has been challenged by the formation of self-assembled life-like abiotic mineral structures, which are proposed to form in soda lakes (García-Ruiz, 1994, 2000García-Ruiz et al., 2002, 2020. Nevertheless, mineral self-assembly was never tested in "natural" soda lake water. ...
... More importantly, extensive research has been done on mineral self-organization to advance the understanding of plausible pathways to biological self-assembly (Hanczyc et al., 2003), biomineralization (Song and Cölfen, 2010;Bergström et al., 2015;Cardoso et al., 2016), the origin of life, and its implication in life detection and prebiotic geochemistry (García-Ruiz, 1994, 2000Saladino et al., 2016;Bizzarri et al., 2018;Barge et al., 2019;McMahon, 2019;. A historical discussion of mineral self-assembly can be found in Cintas (2020) Among these patterns, biomimetic chemical gardens and silica-carbonate biomorphs received significant attention due to their relevance in life detection (García-Ruiz, 1994, 2000García-Ruiz et al., 2002, 2017, 2020, origin of life, and prebiotic chemistry of early Earth and other planets and moons (Russell et al., 1994;Russell and Hall, 1997;Saladino et al., 2016Saladino et al., , 2019García-Ruiz et al., 2017, 2020Bizzarri et al., 2018;Barge et al., 2019). Tubular and vesicular chemical gardens are capable of catalyzing prebiotic chemical reactions leading to the synthesis of organic molecules such as carboxylic acids, amino acids, and nucleobases, suggesting the plausible emergence of life in alkaline early Earth soda oceans (Saladino et al., 2016(Saladino et al., , 2019Bizzarri et al., 2018;Barge et al., 2019;Angelis et al., 2021). ...
... More importantly, extensive research has been done on mineral self-organization to advance the understanding of plausible pathways to biological self-assembly (Hanczyc et al., 2003), biomineralization (Song and Cölfen, 2010;Bergström et al., 2015;Cardoso et al., 2016), the origin of life, and its implication in life detection and prebiotic geochemistry (García-Ruiz, 1994, 2000Saladino et al., 2016;Bizzarri et al., 2018;Barge et al., 2019;McMahon, 2019;. A historical discussion of mineral self-assembly can be found in Cintas (2020) Among these patterns, biomimetic chemical gardens and silica-carbonate biomorphs received significant attention due to their relevance in life detection (García-Ruiz, 1994, 2000García-Ruiz et al., 2002, 2017, 2020, origin of life, and prebiotic chemistry of early Earth and other planets and moons (Russell et al., 1994;Russell and Hall, 1997;Saladino et al., 2016Saladino et al., , 2019García-Ruiz et al., 2017, 2020Bizzarri et al., 2018;Barge et al., 2019). Tubular and vesicular chemical gardens are capable of catalyzing prebiotic chemical reactions leading to the synthesis of organic molecules such as carboxylic acids, amino acids, and nucleobases, suggesting the plausible emergence of life in alkaline early Earth soda oceans (Saladino et al., 2016(Saladino et al., , 2019Bizzarri et al., 2018;Barge et al., 2019;Angelis et al., 2021). ...
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