Nick Lane: The electrical origins of life

The speaker begins by expressing gratitude for the warm welcome and acknowledges the unique experience of giving a talk after a musical performance. They introduce the topic of evolutionary biochemistry, noting the importance of the word 'biochemistry' over 'biology'. The speaker apologizes for the complexity of biochemistry, recognizing that it may not be as easily accessible to those without a background in the field. They set the stage for a discussion on the origin of life and consciousness, hinting at the potential ethical implications of molecular biosciences. The speaker also touches on the difficulty of pinpointing the exact moment of life's origin, even with a hypothetical time machine, due to the lack of consensus among scientists about where to look and what to look for.

The speaker delves into the relationship between chemistry and biology in understanding life's origins. They highlight the role of chemistry in the past 50-60 years and the more recent involvement of biology. The speaker discusses the importance of energy, metabolism, and genetic information in the emergence of life. They use the example of the Kreb cycle to illustrate how energy is generated and used in cells, emphasizing the universality of this process across all life forms. The speaker also introduces the concept of the reverse Kreb cycle, which is involved in biosynthesis, the creation of life's building blocks. They underscore the deep conservation of certain molecules in the Kreb cycle, which are fundamental to all metabolism.

The speaker explores the genetic code and its implications for the origin of life. They discuss the patterns within the codons and amino acids, suggesting that these patterns indicate a non-random assortment in the genetic code. The speaker posits that a random RNA sequence could code a non-random peptide, which, if functional, could lead to natural selection. This perspective challenges the idea of information's mysterious origins in biology. The speaker also introduces the concept of alkaline hydrothermal vents as a potential site for the origin of life, explaining their formation and how they could provide a suitable environment for the chemistry of life to begin.

The speaker discusses the process of serpentinization and its role in the geological and potentially biological history of planets. They explain how this process can lead to the formation of hydrated rock, which may have contributed to the burial of Mars' oceans and its subsequent loss of atmospheric impact. The speaker draws an analogy between the structure of a cell and the topological structure of a planet, noting the similarities in their electrochemical properties. They introduce the idea that the Earth's mantle and oceans can be seen as a large-scale electrochemical flow reactor, which could have facilitated the reactions necessary for life's emergence. The speaker also mentions the discovery of Enceladus' plumes, which are thought to result from a similar process of serpentinization.

The speaker presents a hypothesis for the birth of life, focusing on the role of alkaline hydrothermal vents. They suggest that high concentrations of hydrogen in these vents, when combined with early ocean waters rich in CO2, could create a suitable environment for life's components to form. The speaker describes the potential formation of lipids and amino acids in such an environment, leading to the creation of protocells. They also discuss the possibility of these protocells being templated by the structure of the vents, thus creating a semi-closed system conducive to further chemical reactions. The speaker emphasizes the testability of this hypothesis and the preliminary experimental support for it.

The speaker shares experimental data that supports the hypothesis of life's origins at alkaline hydrothermal vents. They describe experiments using microfluidic chips to create a pH gradient, which successfully drives the reduction of CO2 into organic molecules. The speaker emphasizes the significance of this result, as it represents the first step in the reaction of hydrogen and CO2. They also mention the successful creation of protocells with a lipid membrane and the formation of iron-sulfur clusters, which are crucial for CO2 fixation in modern cells. The speaker highlights the importance of these findings in demonstrating the feasibility of life's chemical origins.

The speaker discusses the remarkable conservation of metabolic pathways across all life forms, comparing it to the consistency of an underground transport map across different cities. They suggest that this conservation indicates the ancient origins of these pathways, predating the genes that code for them. The speaker presents experimental work showing that segments of the Kreb cycle can occur spontaneously in the lab, even in the absence of enzymes or genetic programming. They also mention the successful synthesis of uracil, one of the nucleotide bases, under conditions similar to those found in alkaline hydrothermal vents. These findings support the idea that the chemistry of life could have arisen naturally under the right conditions.

The speaker explores the process of ATP synthesis, focusing on the role of the ATP synthase enzyme. They describe the enzyme's remarkable structure and function, highlighting its efficiency and speed. The speaker also discusses the genetic code, noting the non-random patterns within it. They present evidence from molecular dynamics simulations and NMR studies that suggest a correlation between the structure of amino acids and the bases that code for them. The speaker suggests that these interactions could explain the origins of information in biology and contribute to our understanding of the genetic code's structure.

The speaker ventures into the concept of consciousness in bacteria, emphasizing that it differs from human consciousness. They propose that the electromagnetic fields generated by the proton gradient across cellular membranes provide real-time feedback to bacteria about their state in the environment. The speaker suggests that this feedback could be the basis for a simple form of consciousness in bacteria. They also discuss the role of membrane potential in bacterial behavior and death, noting that the life and death of bacterial cells are closely tied to the state of their membranes. The speaker presents the idea that the integration of information across cellular membranes could be an early form of consciousness, which could have evolved and become more complex in multicellular organisms and eventually in the central nervous system of higher organisms.

In the concluding paragraph, the speaker expresses gratitude to their lab team and funders for their support in exploring the origins of life and consciousness. They acknowledge the bravery of their team in undertaking such challenging research topics and thank the audience for their invitation and attention. The speaker leaves the audience with a thought-provoking perspective on the potential pathways from simple chemical reactions to the complexity of consciousness, inviting further questions and discussions.