Darwin’s warm little pond revisited: from molecules to the origin of life

Abstract

All known cosmic and geological conditions and laws of chemistry and thermodynamics allow that complex organic matter could have formed spontaneously on pristine planet Earth about 4,000 mya. Simple gasses and minerals on the surface and in oceans of the early Earth reacted and were eventually organized in supramolecular aggregates and enveloped cells that evolved into primitive forms of life. Chemical evolution, which preceded all species of extant organisms, is a fact. In this review, we have concentrated on experimental and theoretical research published over the last two decades, which has added a wealth of new details and helped to close gaps in our previous understanding of this multifaceted field. Recent exciting progress in the molecular and genetic analyses of existing life, in particular microorganisms of ancient origin, even supports the possibility that a cellular, self-reproducing common ancestor might be assembled and resurrected in anaerobic cultures at some time in the future. Charles Darwin did not, and indeed, could not, address and specify the earliest phases of life which preceded the Origin of Species. However, in a famous letter, he sketched "a warm little pond with all sorts of... (chemicals, in which) ...a protein was chemically formed." We try to trace the impact of his charming clear-sighted metaphor up to the present time.

On the Theory of Evolution Versus the Concept of Evolution: Three Observations

“…The experiments of Stanley Miller (1953) from the 1950s did precisely that: he tested the hypothesis that simple organic molecules (amino acids), precursors of life, could have been generated in a lifeless, primitive Earth (the significance of these experiments has been discussed in detail; Bada and Lazcano 2003; Johnson et al 2008; Lazcano and Bada 2008). Despite the simplicity of Miller's approach (see Lazcano and Bada 2008), his findings allowed scientists to envision an obvious continuum from the inorganic world to the chemical organic bloom, and to the origin and diversification of life from ordinary matter (Follmann and Brownson 2009; Lazcano 2010). The concept of evolution was the foundation of Miller's scientific thinking and laboratory logic, and his findings as a “pioneer prebiotic chemist” enriched the “body of knowledge” called the theory of evolution.…”

“…Significant articles, published in Evolution: Education and Outreach and other prestigious journals, analyze this holistic view of evolution and their titles are compelling: Science and the Concept of Evolution: From the Big Bang to the Origin and Evolution of Life (Zaikowski et al 2008), Cosmic Evolution (Krauss 2010), Charles Darwin and the Origin of Life (Peretó et al 2009), and Darwin's Warm Little Pond Revisited: From Molecules to the Origin of Life (Follmann and Brownson 2009). By integrating physics, chemistry, and biology, modern scientists and education scholars secure an interdisciplinary approach to understanding the evolutionary process, beginning with the formation of the universe and emergence of the simplest elements, and continuing toward more complex elements and molecules, including prebiotic compounds and, ultimately, the molecular diversity and complexity of today's living organisms (see Zaikowski et al 2008 for an example of a multi-disciplinary approach to addressing these topics in the science class; in addition, at Arizona State University, LM Krauss offers the course PHY394 Origins: From the Big Bang to Life on Earth and Beyond, see references for website link).…”

Stability of free and mineral-protected nucleic acids: Implications for the RNA world

“…The complete absence of a "fossil record" for the type of proto-biomolecules present in this era means that there is no way any hypothesis can be proved to be correct. However, it is possible to make reasonable proposals and then experimentally investigate the processes that may have led to the emergence of the first biomolecules, including the first genetic material and the first living organisms (Follmann and Brownson, 2009;Budin and Szostak, 2010).…”

At the very beginning of life on Earth: the thiol-rich peptide (TRP) world hypothesis

“…But these surfaces, if existing, were indeed over wet, due to the large amount of water present in the atmosphere and frequent rains. Many captivating scenarios have been proposed since Darwin's little hot pond (Follmann andBrownson, 2009, Damer, 2016): coastal zone (Lathe, 2003), dehydrating/hydrating cycling (Ross and Deamer, 2016), hydrothermal vents (Miller and Bada, 1988), tectonic faults (Schreiber et al, 2012), geothermal fields (Mulkidjanian et al, 2012), ocean abysses (Di Giulio, 2005), surface metabolism (Wächtershäuser, 2006), salt-induced peptide formation (Fitz et al, 2007), a stereochemical era (Fontecilla-Camps, 2014), thermal gradients (Agerschou et al, 2017), the sum of various specific spots (Monard, 2016, Stüeken et al, 2013… To these scenarios, in which life occurred "somewhere", we prefer a scenario in which life came out everywhere or, at least, anywhere in a roughly homogeneous ocean.…”