Fig 1 - uploaded by Bruce Damer
Content may be subject to copyright.
Source publication
A four-part essay linking the Origin of Life in hot spring pools on land to the Extended Evolutionary Synthesis.
Part 1: The Origin of Evolution
Part 2: Programming Without a Programmer
Part 3: The Quest to Test (or Falsify) the Hot Spring Hypothesis
Part 4: The Progenote, Chickens, Eggs and the Extended Evolutionary Synthesis
Similar publications
This study aimed to assess the potentiality of Digital Elevation Model (DEM)-derived flow direction in mapping geologic structures, specifically in areas with thick overburden of soil or volcanic materials such as in the Rungwe Volcanic Province, SW Tanzania. Clustering of flow directions based on trends of structure sets found in the study area wa...
Citations
... As described earlier, the polymers can be encapsulated in microscopic lipid vesicles and form protocells, each having a different composition from all the rest. The progenitor provides a sort of "proto-niche" ( Damer 2019 ;Odling-Smee et al. 2024 ) that protects organic compounds from degradative forces such as hydrolysis. The dynamic fl uidity of membranes also offers intrinsic mechanisms for concentration, transport, and combinatorial selection. ...
... A protocell aggregate can be considered to be a prototypical form of niche construction as described by Odling-Smee et al. (2003). Damer (2016Damer ( , 2019 extended this concept to prebiotic conditions in which protocell populations form moist gel aggregates during the drying process that protect individual protocells and their polymer cargoes against shear forces, pH extremes, and temperature changes. A gel could also maintain a stable concentration of ionic solutes, thereby protecting protocells against osmotic stress. ...
We present a testable hypothesis related to an origin of life on land in which fluctuating volcanic hot spring pools play a central role. The hypothesis is based on experimental evidence that lipid-encapsulated polymers can be synthesized by cycles of hydration and dehydration to form protocells. Drawing on metaphors from the bootstrapping of a simple computer operating system, we show how protocells cycling through wet, dry, and moist phases will subject polymers to combinatorial selection and draw structural and catalytic functions out of initially random sequences, including structural stabilization, pore formation, and primitive metabolic activity. We propose that protocells aggregating into a hydrogel in the intermediate moist phase of wet-dry cycles represent a primitive progenote system. Progenote populations can undergo selection and distribution, construct niches in new environments, and enable a sharing network effect that can collectively evolve them into the first microbial communities. Laboratory and field experiments testing the first steps of the scenario are summarized. The scenario is then placed in a geological setting on the early Earth to suggest a plausible pathway from life's origin in chemically optimal freshwater hot spring pools to the emergence of microbial communities tolerant to more extreme conditions in dilute lakes and salty conditions in marine environments. A continuity is observed for biogenesis beginning with simple protocell aggregates, through the transitional form of the progenote, to robust microbial mats that leave the fossil imprints of stromatolites so representative in the rock record. A roadmap to future testing of the hypothesis is presented. We compare the oceanic vent with land-based pool scenarios for an origin of life and explore their implications for subsequent evolution to multicellular life such as plants. We conclude by utilizing the hypothesis to posit where life might also have emerged in habitats such as Mars or Saturn's icy moon Enceladus.
“To postulate one fortuitously catalyzed reaction, perhaps catalyzed by a metal ion, might be reasonable, but to postulate a suite of them is to appeal to magic.”
—Leslie Orgel
