Silica Precipitation in a Wet–Dry Cycling Hot Spring Simulation Chamber

Abstract

Terrestrial hot springs have emerged as strong contenders for sites that could have facilitated the origin of life. Cycling between wet and dry conditions is a key feature of these systems, which can produce both structural and chemical complexity within protocellular material. Silica precipitation is a common phenomenon in terrestrial hot springs and is closely associated with life in modern systems. Not only does silica preserve evidence of hot spring life, it also can help it survive during life through UV protection, a factor which would be especially relevant on the early Earth. Determining which physical and chemical components of hot springs are the result of life vs. non-life in modern hot spring systems is a difficult task, however, since life is so prevalent in these environments. Using a model hot spring simulation chamber, we demonstrate a simple yet effective way to precipitate silica with or without the presence of life. This system may be valuable in further investigating the plausible role of silica precipitation in ancient terrestrial hot spring environments even before life arose, as well as its potential role in providing protection from the high surface UV conditions which may have been present on early Earth.

Building the uracil skeleton in primitive ponds at the origins of life: carbamoylation of aspartic acid

“…NCA on the rocks: preliminary studies on silica. Amorphous silica (SiO 2 ) is well-known to be efficient for prebiotic condensation reactions, especially those of amino acids to peptides 35 , and is a prebiotically realistic mineral [36][37][38] . It is a moderately acidic catalyst, its catalytic properties relying on H-bonding and silanol acidity 39,40 .…”

Factoring Origin of Life Hypotheses into the Search for Life in the Solar System and Beyond

“…One such facility is the McMaster Planet Simulator, which has already simulated photochemistry in the atmosphere of Titan [194]. The University of New South Wales (UNSW) and the University of Cincinnati are constructing hot spring simulators to test the hypothesis that life began in hydrothermal fields [195]. Multiple submarine hydrothermal vent simulation chambers are active (e.g., [196]).…”

Ring‐Closure on the Rocks in a Prebiotic Environment

“…The reference material for our study was amorphous silica (SiO 2 ). This prebiotically realistic mineral [45–47] is a moderately acidic catalyst, with catalytic properties depending on weakly Brönsted acidic silanols, that probably act by H‐bonding to the reagents rather than direct proton transfer [48,49] . It is not only known to be efficient for prebiotic intermolecular condensations, such as of amino acids into peptides, [50,51] but also for intramolecular condensations such as that of L‐glutamic acid into pyroglutamic acid or of dimeric peptides into diketopiperazines (DKP) [52,53] .…”