Our goal is to investigate the internal design of a hypothetical Simplest possible Self Replicator (SSR) modeled after a single cell organism. We start from a simple set of assumptions regarding the exchanges of the SSR with its environment: intake of materials for internal processes, element construction and energy generation and output of refuse materials. There are only two requirements for the SSR: to have an enclosure and to be capable of creating an identical copy of itself. The focus of the investigation is a concrete, material SSR, not an abstraction like cellular automata or a software or simulated artifact. Our approach is to take an empirical, deductive approach and in a logical manner identify step by step the elements and functions that, by necessity, must be part of the SSR.
It’s conceivable we could get some serious answers about origin of life if we started by taking the problem seriously from an engineering perspective.
For sure, this kind of thing has not got us anywhere:
“RNA first” proponent Leslie Orgel responded irritably to Shapiro’s metabolism first model, “solutions … dependent on ‘if pigs could fly’ hypothetical chemistry are unlikely to help.” Near the end of his life, Orgel had perhaps forgotten that he himself once co-authored a paper with Francis Crick speculating that extraterrestrials might have started life.
Numerous less publicized models wallop through the science press, on the hope, perhaps, of a lucky strike: For example, not-obviously-promising substances such as hydrogen, ammonia, hydrogen cyanide, formaldehyde, or peptides, possibly kick started life. Maybe metals acted as catalysts. Or mica sheets. Otherwise, cold temperatures or ice helped life get started, despite the fact that cold reduces chemical reaction speed. Or a high salt environment. Or hot springs. No surprise that science writer Colin Barras observes that origin of life is “a highly polarised field of research.” Most fields have only two poles, not twenty. More.
See also: With Enceladus the toast of the solar system, here’s a wrap-up of the origin-of-life problem.
and
The Science Fictions series at your fingertips (origin of life)
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Hat tip: Natural Genetic Engineering