VI. Earth Life Emergence: Development of Body, Brain, Selves and Societies
2. The Origins of Life
Froese, Tom, et al. Motility at the Origin of Life: Its Characterization and a Model. Artificial Life. Online February, 2013. As the Abstract notes, at our present mature stage of origins research, Tom Froese and Takashi Ikegami, University of Tokyo, and Nathaniel Virgo, Max Planck Institute for Biogeochemistry, propose to join vying replicator and metabolism options by way of an “information-compartment-metabolism first” consensus. This triad has variously arisen as a preferred definition for living systems, search this section. In regard, an organism’s propensity for movement is seen to unfold through a sequence of “being, doing, developing, and evolving” phases. It is then broached that by virtue of such a reconstructed quantification, a new animate creation may commence via human intentional continuance.
Due to recent advances in synthetic biology and artificial life, the origin of life is currently a hot topic of research. We review the literature and argue that the two traditionally competing replicator-first and metabolism-first approaches are merging into one integrated theory of individuation and evolution. We contribute to the maturation of this more inclusive approach by highlighting some problematic assumptions that still lead to an impoverished conception of the phenomenon of life. In particular, we argue that the new consensus has so far failed to consider the relevance of intermediate time scales. We propose that an adequate theory of life must account for the fact that all living beings are situated in at least four distinct time scales, which are typically associated with metabolism, motility, development, and evolution. In this view, self-movement, adaptive behavior, and morphological changes could have already been present at the origin of life. In order to illustrate this possibility, we analyze a minimal model of lifelike phenomena, namely, of precarious, individuated, dissipative structures that can be found in simple reaction-diffusion systems. Based on our analysis, we suggest that processes on intermediate time scales could have already been operative in prebiotic systems. They may have facilitated and constrained changes occurring in the faster- and slower-paced time scales of chemical self-individuation and evolution by natural selection, respectively. (Abstract)
Fry, Iris. Are the Different Hypotheses on the Emergence of Life as Different as They Seem? Biology & Philosophy. 10/4, 1995. The Tel Aviv University philosopher and author of The Emergence of Life on Earth (Rutgers, 2000), achieves in this earlier piece, cited by Richard Egel (2012) as akin to Jeffery Wicken’s prescience, a synoptic entry into the pantheon of 20th century views. Two prime schools or persuasions can be identified. An “almost miracle camp” allows a mechanical nature wherein life is so radical as to be either divinely sparked or a capricious accident. On the other hand, a “continuity thesis or law camp” avers that biology and physics must somehow be seamlessly unified. This preferred path is seen to hold from Alexander Oparin and J. B. S. Haldane to Manfred Eigen, Marcel Florkin (biochemical orthogenesis), Sidney Fox, Harold Morowitz, Christian de Duve, onto Stuart Kauffman and others. Circa the mid 1990s, the growing evidence for non-equilibrium thermodynamics and self-organizing systems is seen to bode for this organic resolve, a synthesis beyond only lumpen mechanism or vitalism due to a special principle.
This paper was devoted to the discussion of, what I have coined, the continuity thesis. This thesis states that the development of life from matter is a gradual process to be explained on the basis of physical principles. The thesis rejects the “chance camp” notion, expressed by several scientists, that the gap between inanimate matter and life was bridged by a unique, miraculous event. I described the continuity thesis as a philosophical presupposition that unites researchers of the origin of life, and that forms the basis for the “law damp.” Surveying several models suggested in the field, e.g., replication-first and cell-first theories, I pointed out the presence of the continuity thesis in all of them, despite their differences. The assumption that life emerged from matter based on physical mechanisms of self-organization is, I claimed, not a “passive ingredient” of all these theories. When acknowledged, this assumption can serve as a guidance to devise more probable scenarios. (414)
Fry, Iris. The Emergence of Life on Earth. New Brunswick, NJ: Rutgers University Press, 2000. The Technion – Israel Institute of Technology historian of science achieves a most complete, incisive statement at the time of this broad endeavor across centuries and continents. Please then see her 2011 concise update next. The work runs from antiquity to Immanuel Kant, Louis Pasteur, Alexander Oparin, onto Manfred Eigen and Freeman Dyson, and everyone else along the way who has made a contribution. She picks up early on the field’s sorting into replication or metabolism camps, now a main divide as the 2011 paper reports. But it is her initial statement, per the quote, as a natural philosopher that poses a rarest attempt to make a stand and frame a conclusion, which academia so avoids, to admit realize an inherently organic genesis universe.
It is the claim of some biologists – fewer today than in the past – that due to the enormous complexity of even the most primitive living system, chances of its emergence are extremely small. Some of these scientists view the origin of life as a rare “happy accident,” as “almost a miracle.” Relying on a similar argument but drawing from it very different conclusions, creationists deny the natural emergence of life and uphold the necessity of a divine intervention. This book will provide scientific and philosophical arguments denying such claims. In agreement with most researchers in the origin-of-life field today, it is my contention that within the realistic confines of space and time of our universe, the emergence could not have been the result of chance. Rather it involved the working of physical and chemical mechanisms responsible for the self-organization of matter into living systems. (7)
The Role of Natural Selection in the Origin of Life.
Origins of Life and Evolution of Biospheres.
The author of a 2000 review, The Emergence of Life on Earth, noted above, can a decade on report significant advances as researchers now mostly divide into two camps or persuasions. As the quote avers, an iconic sorting has arisen between an emphasis on discrete nucleotide molecules – ‘gene-first’, or in favor of primal autocatalytic, self-organizational processes – ‘metabolism first.’ A necessity for the gene group is the formation of membrane enclosed compartments or proto-cells to house such RNA informants. This feature, posed early on by Alexander Oparin and Sidney Fox, is seen to bridge into the equally real and vital realm of dynamic “metabolic” hypercycles.
It is commonly accepted among origin-of-life scientists that the emergence of life was an evolutionary process involving at one stage or other the working of natural selection. Researchers disagree, however, on the nature of the chemical infrastructure that could have formed prebiotically, enabling the evolutionary process. The division of the origin-of-life research community into `geneticists' and `metabolists' usually revolves around the issue whether the first to arise prebiotically was a genetic polymer or a primitive metabolic system. In this paper I offer an alternative classification based on the attitude to the onset of natural selection. From this perspective I add to the conventional division between gene-first and metabolism-first groups a position I call "preparatory metabolism". (Abstract, 3)
Garcia, Adrien, et al. The Astrophysical Formation of Asymmetric Molecules and the Emergence of a Chiral Bias. Life. 9/1, 2019. Université Côte d’Azur, CNRS, France, and Aarhus University, Denmark scientists report a persistent proclivity of cosmic nature to form a rich variety of precursor complex biochemicals.
The biomolecular homochirality in living organisms has been investigated for decades, but its origin remains poorly understood. It has been shown that circular polarized light and other energy sources are capable of inducing small enantiomeric excesses in primary biomolecules such as amino acids or sugars. Since the first findings of amino acids in carbonaceous meteorites, a scenario in which essential chiral biomolecules originate in space and are delivered by celestial bodies has arisen. In this review we summarize the discoveries in amino acids, sugars, and organophosphorus compounds in meteorites, comets, and laboratory-simulated interstellar ices. (Abstract excerpt)
Goldenfeld, Nigel, et al. Universal Biology and the Statistical Mechanics of Early Life. Philosophical Transactions of the Royal Society A. Vol. 375/Iss. 2109, 2017. A paper by University of Illinois systems biophysicists for this Origins of Life issue which delves into the rootings and continuity that organic/genetic entities ought to have with an abiding physical cosmos. As the Abstract cites, an array of material tendencies (see second quote) seem to portend precursor biomolecular forms. Again, as living systems become known to inhere natural, dynamic principles, they can better merge with a physical ground which is in turn becoming more animate and fecund.
All known life on the Earth exhibits at least two non-trivial common features: the canonical genetic code and biological homochirality, both of which emerged prior to the Last Universal Common Ancestor state. This article describes recent efforts to provide a narrative of this epoch using tools from statistical mechanics. During the emergence of self-replicating life far from equilibrium in a period of chemical evolution, minimal models of autocatalysis show that homochirality would have necessarily co-evolved along with the efficiency of early-life self-replicators. Dynamical system models of the evolution of the genetic code must explain its universality and its highly refined error-minimization properties. These have both been accounted for in a scenario where life arose from a collective, networked phase where there was no notion of species and perhaps even individuality itself. We show how this phase ultimately terminated during an event sometimes known as the Darwinian transition, leading to the present epoch of tree-like vertical descent of organismal lineages. (Abstract)
Greenwell, Chris and Peter Coveney. Layered Double Hydroxide Minerals as Possible Prebiotic Information Storage and Transfer Compounds. Origins of Life and Evolution of Biospheres. 36/1, 2006. This substrate is suggested as the necessary suitable matrix which not only had the capacity to replicate, but could undergo discrete inherited mutations.
Guttenberg, Nicholas, et al. Selection First Path to the Origin of Life. arXiv:1706.05831. As the quote details, with Nathaniel Virgo, Chris Butch, and Norman Packard, Earth-Life Science Institute, Tokyo Institute of Technology researchers propose a synthesis beyond present models as a better, more integral, way to reconstruct. By their perspective, an informational quality can now be attributed to self-amplifying populations.
We propose an alternative to the prevailing two origin of life narratives, one based on a replicator first hypothesis, and one based on a metabolism first hypothesis. Both hypotheses have known difficulties: All known evolvable molecular replicators such as RNA require complex chemical (enzymatic) machinery for the replication process. Likewise, contemporary cellular metabolisms require several enzymatically catalyzed steps, and it is difficult to identify a non-enzymatic path to their realization. We propose that there must have been precursors to both replication and metabolism that enable a form of selection to take place through action of simple chemical and physical processes. We model a concrete example of such a process, repeated sequestration of binary molecular combinations after exposure to an environment with a broad distribution of chemical components, as might be realized experimentally in a repeated wet-dry cycle. We show that the repeated sequestration dynamics results in a selective amplification of a very small subset of molecular species present in the environment, thus providing a candidate primordial selection process. (Abstract)
Hanczyc, Martin. Metabolism and Motility in Prebiotic Structures. Philosophical Transactions of the Royal Society B. 366/2885, 2011. A paper in an issue on The Chemical Origins of Life and its Early Evolution, see Lilley below. In a similar way as Leroy Cronin (search), a University of Southern Denmark, Center for Fundamental Living Technology, biochemist reports an inherent, persistent tendency of so-called “inorganic” materiality to congeal into vesicular droplets, in some guise as primordial protocells. May thus one add an even earlier stage to animate nature’s sequential nest of dolled-up compartmental cells and multicellular selves, lately reaching us writer and reader. Newly edified by this discovery, may we intentionally continue such communality as “social proto-cells,” of nominal 100 persons, the archetypal human grouping, as Sustainable Ecovillages herein personifies?
Easily accessible, primitive chemical structures produced by self-assembly of hydrophobic substances into oil droplets may result in self-moving agents able to sense their environment and move to avoid equilibrium. These structures would constitute very primitive examples of life on the Earth, even more primitive than simple bilayer vesicle structures. A few examples of simple chemical systems are presented that self-organize to produce oil droplets capable of movement, environment remodelling and primitive chemotaxis. Such motile agents would be capable of finding resources while escaping equilibrium and sustaining themselves through an internal metabolism, thus providing a working chemical model for a possible origin of life. (2885)
Hazen, Robert. Genesis: The Scientific Quest for Life’s Origin. Washington, DC: Joseph Henry Press, 2005. A synopsis of this premier perception of an innate gestation is cited in Current Vistas.
Hazen, Robert. Geochemical Origins of Life. Knoll, Andrew, et al, eds. Fundamentals of Geobiology. New York: Wiley-Blackwell, 2012. In a volume reviewed more in A Living Planet, the Carnegie Institution of Washington geochemist and author proposes, from this vista, that a “progressive sequence” from physical matter to organic entities can be attributed to the innate action of self-organizing, complex adaptive systems. By these lights, the “emergence of natural selection” occurs quite after and ancillary to this vitalizing force. The chapter concludes by saying such an inclusive synthesis can settle the current metabolism or replication first argument, as the second quotes cites.
Emergence as a Unifying Concept in Origins Research Life’s origins can be modeled as a sequence of so-called ‘emergent’ events, each of which added new structure and chemical complexity to the prebiotic Earth. Observations of numerous everyday phenomena reveal that new patterns commonly emerge when energy flows through a collection of many interacting particles. (315) In the words of John Holland….emergent systems display three distinctive characteristics: they arise from the interactions of many ‘agents,’ energy flows through those systems, and they display new patterns or behaviors that are not manifest by the individual agents. (315)
Hazen, Robert. The Emergence of Patterning in Life’s Origin and Evolution. International Journal of Developmental Biology. 53/5-6, 2009. An update by a prime contributor to the revolution that the universe is not alien to or bereft of life, but rather an ordained nature seems made to generate complex viable systems. In so doing, generic complex, self-organizing, adaptive systems composed of many agents in informed interrelation are increasingly and robustly found everywhere.
Three principles guide natural pattern formation in both biological and non-living systems: (1) patterns form from interactions of numerous individual particles, or “agents,” such as sand grains, molecules, cells or organisms; (2) assemblages of agents can adopt combinatorially large numbers of different configurations; (3) observed patterns emerge through the selection of highly functional configurations. (683)