Uncovering the thermal pathways to life's origins

Uncovering the thermal pathways to life's origins
by Robert Schreiber
Berlin, Germany (SPX) Apr 05, 2024

The enigma of life's origins is as complex as life itself, with myriad intricate processes unfolding within cells. From protein synthesis to DNA replication, the coordination and concentration of reaction partners are crucial for cellular operations. Evolution has refined these processes over billions of years, optimizing the efficiency and accuracy of vital biochemical activities.

This complexity contrasts sharply with the chaotic conditions of Earth four billion years ago when prebiotic reactions laid the groundwork for life. The challenge of aligning the appropriate substances at the right moments was formidable in the dilute "primordial soup" of Earth's early days. The mystery of how nature orchestrated the conditions conducive to life's emergence has puzzled scientists for years.

A study led by LMU biophysicists Dr. Christof Mast and Professor Dieter Braun, along with geoscience Professor Bettina Scheu, offers insights into this ancient puzzle. Published in Nature, their research reveals how simple heat flows could introduce order into the chemical chaos of primordial Earth, facilitating the earliest prebiotic reactions. Heat, a byproduct of numerous geological and chemical activities, likely generated ubiquitous heat flows in the prebiotic world. These flows, when passing through narrow, water-filled fissures created by the cooling of molten rock, could induce water convection and direct molecular movement along the heat gradient. This dual phenomenon of convection and thermophoresis could lead to the accumulation and selective concentration of dissolved molecules in specific locales.

The team has experimentally validated the selective accumulation of over 60 prebiotic building blocks, such as nucleobases and amino acids, demonstrating significant variations in their thermophoretic behaviors. This diversity in enrichment across rock fissures could yield distinct mixtures of prebiotic substances in each crevice, setting the stage for a variety of prebiotic chemical scenarios despite the initial solution's uniform dilution.

This research underscores the potential of natural, thermal-driven processes to establish a primitive "molecular kitchen," where the essential components for life were neatly organized, awaiting the right conditions to combine into the building blocks of life. The findings, part of the "Molecular Evolution in Prebiotic Environments" (CRC 392) project, aim to explore the plethora of life's recipes that could emerge from such prebiotic systems.

Research Report:Heat flows enrich prebiotic building blocks and enhance their reactivity