Contrasting theories of life: Historical context, current theories. In search of an ideal theory

A biochemically-realisable relational model of the self-manufacturing cell

“…I particularly enjoy the understated way he describes his elation at figuring out how to do this: “Thus I was edified to discover that, under stringent but not prohibitively strong conditions, such replication essentially comes along for free, requiring nothing else but what is already in the diagram.” He then sketches out “the simplest way this can come about (although it is not the only way)” by introducing an invertible evaluation map to yield Fig. 4 g , a mathematical sleight-of-hand that, while perfectly sound, has caused much confusion as well as misinterpretations that led to (all conclusively refuted) accusations of being wrong (see Cornish-Bowden and Cárdenas (2020)). What is, however, abundantly clear from his writings is that Rosen constructed the replication map purely on the basis of mathematical convenience, and not because he had some physical realisation in mind.…”

“…The amplification achieved by autocatalysis does of course result in growth in the number of chemoton molecules in the system and a concomitant increase in reaction rates through mass-action, but this applies equally to the rates of the side reactions and therefore does not solve the problem. This problem of side reactions is a matter that I alerted one of the authors of Cornish-Bowden and Cárdenas (2020) to, and which they mention and acknowledge in their review. The reason for referring to it here is that pruning the ( F,A ) cell model into three blocks that correspond to the three cycles of the chemoton provides a stark visual picture (Fig.…”

“…Theories of life abound, so one would expect that by now, more than a century after the birth of biochemistry, we should be able to understand self-manufacture at the level of the modern cell’s molecular processes. However, the recent in-depth review by Cornish-Bowden and Cárdenas (2020) provides no evidence that any of the theories of life that directly address the question of cellular and organismal selfmanufacture, of which Maturana and Varela’s (1980) theory of autopoiesis, Rosen’s (1991) theory of metabolism-repair or ( M,R )-systems, and Gánti’s (2003c) chemoton theory are the most prominent examples, have found a satisfactory translation into cell biochemistry. Unfortunately the analysis by Hofmeyr (2017), which provides the basis for just such a translation, was for some reason not discussed in the review.…”

Exploitation of Heterosis in Pearl Millet: A Review

“…Genetic variability between the parents and hybrids was measured using the enzyme fluxes of glucose, glycerol and acetaldehyde in yeast. For most hybrids, positive heterosis was observed when their metabolic fluxes were compared with the parental fluxes and concluded that heterosis can be manifested to a greater extent provided the parents used for crossing are phenotypically close with wide variations in enzyme concentrations; therefore, using metabolic control analysis, heterosis can be easily exploited by deriving the shape of curves representing phenotype to genotype relationship [ 76 , 77 ].…”

Molecules, Information and the Origin of Life: What Is Next?

“…Maturana, however, stands on a plain philosophical ground. Researchers are still searching for an ideal theory based on biology about how life arose and why it appears in a completely distinct entity respect to crystals, despite its chemico-physical nature [26]. Alongside with the concept of "self-replication" and "self-organization", characterizing the idea of what "a life is", some controversial issue may occur, as a virus or a prion, for example, are not properly considered living systems, i.e., organisms, despite their self-replicating and self-organizing endowment.…”