The definition, origin and recreation of life remain elusive. As others have suggested, only once we put life into reductionist physical terms will we be able to solve those questions. To that end, this work proposes the phenomenon of life to be the product of two dissipative mechanisms. From them, one characterises extant biological life and deduces a testable scenario for its origin. The proposed theory of life allows its replication, reinterprets ecological evolution and creates new constraints on the search for life.

Ervin Bauer (1890-1938) made historical contributions to contemporary biology, provided a new definition of life, defined the contents of theoretical biology. He worked in different countries, perturbed by deep historical events. These historical events necessarily impacted his fate and finally led to the violent loss of his life and the life of his wife. His work and with it his theory of life had a no less complicated history than the history of his personal life. Bauer\'s main work \"Theoretical Biology\" was published in 1935 in Russian. The author and his wife Stefánia became victims of the Great Purge. They were executed in 1938, all their publications were banned and most copies of \"Theoretical Biology\" destroyed. Ervin and Stefánia Bauer were rehabilitated in 1956 but renewed publication of Bauer\'s works was delayed. The first reprint edition of \"Theoretical Biology\" of 1967 was not in Russian, but was a translation into Hungarian, the native language of Bauer. The first Russian reprint of \"Theoretical Biology\", in which the original Russian chapters are followed by short English summaries, was published in Hungary in 1982. This edition was prepared by Hungarian and Russian scientists. The best-known Russian edition of \"Theoretical Biology\" was published in 2002 in St. Petersburg. A complete English translation of Bauer\'s main work \"Theoretical Biology\" is still outstanding.

The main unique features of biological systems are reviewed, and four necessary and sufficient attributes of life are formulated, based on the ideas of Ervin Bauer. The possibility of the occurrence of each of these attributes during the origin of life is analyzed. As a result, different scenarios for the origin of life are presented, with their pros and cons. Next, the mainstream of biological evolution is discussed, considering it as a special case of general complexification, and structuredness is defined as a quantitative measure of structural complexity. By introducing the concepts of post-dissipative structure and ratcheting process based on \"frozen\" patterns, their role in the generation of biological structures underlying biological evolution is demonstrated. Furthermore, it is proposed that all living things can be divided into micro- (unicellular) and macro- (multicellular) creatures, which differ from each other even more radically than the difference between prokaryotes and unicellular eukaryotes. Then the fifth, sufficient, but not necessary attribute of life, hierarchicality, is formulated, which is fully applicable only to macrolife. It is also shown that living organisms are primarily chemodynamic rather than thermodynamic systems, and three basic laws of biochemodynamics are formulated. Finally, fifteen basic features of living beings, grouped into four basic blocks, are summarized.

In this paper we explore the relevance and integration of system theory and thermodynamics in terms of the Earth system. It is proposed that together, these fields explain the evolution, organization, functionality and directionality of life on Earth. We begin by summarizing historical and current thinking on the definition of life itself. We then investigate the evidence for a single unit of life. Given that any definition of life and its levels of organization are intertwined, we explore how the Earth system is structured and functions from an energetic perspective, by outlining relevant thermodynamic theory relating to molecular, metabolic, cellular, individual, population, species, ecosystem and biome organization. We next investigate the fundamental relationships between systems theory and thermodynamics in terms of the Earth system, examining the key characteristics of self-assembly, self-organization (including autonomy), emergence, non-linearity, feedback and sub-optimality. Finally, we examine the relevance of systems theory and thermodynamics with reference to two specific aspects: the tempo and directionality of evolution and the directional and predictable process of ecological succession. We discuss the importance of the entropic drive in understanding altruism, multicellularity, mutualistic and antagonistic relationships and how maximum entropy production theory may explain patterns thought to evidence the intermediate disturbance hypothesis.

It should be the ultimate goal of any theory of evolution to delineate the contours of an integrative system to answer the question: How does life (in all its complexity) evolve (which can be called mega-evolution)? But how to plausibly define \'life\'? My answer (1994-2023) is: \'life\' sounds like a noun, but denotes an activity, and thus is a verb. Life (L) denotes nothing else than the total sum (∑) of all acts of communication (transfer of information) (C) executed by any type of senders-receivers at all their levels (up to at least 15) of compartmental organization: L = ∑C. The \'communicating compartment\' is better suited to serve as the universal unit of structure, function and evolution than the cell, the smallest such unit. By paying as much importance to communication activity as to the Central Dogma of molecular biology, a wealth of new insights unfold. The major ones are as follows. (1) Living compartments have not only a genetic memory (DNA), but also a still enigmatic cognitive and an electrical memory system (and thus a triple memory system). (2) Complex compartments can have up to three types of progeny: genetic descendants/children, pupils/learners and electricians. (3) Of particular importance to adaptation, any act of communication is a problem-solving act because all messages need to be decoded. Hence through problem-solving that precedes selection, life itself is the driving force of its own evolution (a very clever but counterintuitive and unexpected logical deduction). Perhaps, this is the \'vital force\' philosopher and Nobel laureate (in 1927) Henri Bergson searched for but did not find.

The multifarious internal workings of organisms are difficult to reconcile with a single feature defining a state of \'being alive\'. Indeed, definitions of life rely on emergent properties (growth, capacity to evolve, agency) only symptomatic of intrinsic functioning. Empirical studies demonstrate that biomolecules including ratcheting or rotating enzymes and ribozymes undergo repetitive conformation state changes driven either directly or indirectly by thermodynamic gradients. They exhibit disparate structures, but govern processes relying on directional physical motion (DNA transcription, translation, cytoskeleton transport) and share the principle of repetitive uniplanar conformation changes driven by thermodynamic gradients, producing dependable unidirectional motion: \'heat engines\' exploiting thermodynamic disequilibria to perform work. Recognition that disparate biological molecules demonstrate conformation state changes involving directional motion, working in self-regulating networks, allows a mechanistic definition: life is a self-regulating process whereby matter undergoes cyclic, uniplanar conformation state changes that convert thermodynamic disequilibria into directed motion, performing work that locally reduces entropy. \'Living things\' are structures including an autonomous network of units exploiting thermodynamic gradients to drive uniplanar conformation state changes that perform work. These principles are independent of any specific chemical environment, and can be applied to other biospheres.

The question of the origin of life is a tenacious question that challenges many branches of science but is also extremely multifaceted. While prebiotic chemistry and micropaleontology reformulate the question as that of explaining the appearance of life on Earth in the deep past, systems chemistry and synthetic biology typically understand the question as that of demonstrating the synthesis of novel living matter from nonliving matter independently of historical constraints. The objective of this contribution is to disentangle the different readings of the origin-of-life question found in science. We identify three main dimensions along which the question can be differently constrained depending on context: historical adequacy, natural spontaneity, and similarity to life-as-we-know-it. We argue that the epistemic status of what needs to be explained-the explanandum-varies from approximately true when the origin-of-life question is the most constrained to entirely speculative when the constraints are the most relaxed. This difference in epistemic status triggers a shift in the nature of the origin-of-life question from an explanation-seeking question in the most constrained case to a fact-establishing question in the lesser-constrained ones. We furthermore explore how answers to some interpretations of the origin-of-life questions matter for other interpretations.

This is a digest of how various researchers in biology and astrobiology have explored questions of what defines living organisms-definitions based on functions or structures observed in organisms, or on systems terms, or on mathematical conceptions like closure, chirality, quantum mechanics and thermodynamics, or on biosemiotics, or on Darwinian evolution-to clarify the field and make it easier for endeavors in artificial intelligence to make progress. Current ideas are described to promote work between astrobiologists and computer scientists, each concerned with living organisms. A four-parameter framework is presented as a scaffold that is later developed into what machines lack to be considered alive: systems, evolution, energy and consciousness, and includes Jagers operators and the idea of dual closure. A novel definition of consciousness is developed which describes mental objects both with and without communicable properties, and this helps to clarify how consciousness in machines may be studied as an emergent process related to choice functions in systems. A perspective on how quantization, acting on nucleic acids, sets up natural limits to system behavior is offered as a partial address to the problem of biogenesis.

Here we have proposed a new biological definition of life based on the function and reproduction of existing genes and creation of new ones, which is applicable to both unicellular and multicellular organisms. First, we coined a new term \"genetic information metabolism\" comprising functioning, reproduction, and creation of genes and their distribution among living and non-living carriers of genetic information. Encompassing this concept, life is defined as organized matter that provides genetic information metabolism. Additionally, we have articulated the general biological function of life as Tetz biological law: \"General biological function of life is to provide genetic information metabolism\" and formulated novel definition of life: \"Life is an organized matter that provides genetic information metabolism\". New definition of life and Tetz biological law allow to distinguish in a new way living and non-living objects on Earth and other planets based on providing genetic information metabolism.

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