Revolution by Natural Selection - Professor Nick Lane, University College London

The paragraph introduces Professor Nick Lane, an evolutionary biochemist at University College London, who will discuss the history of life from an energy perspective. The lecture series theme is 'Revolution', and he aims to explain the unusual trajectory of evolution through the lens of energy flow. The introduction also acknowledges the Darwin College lecture series and the significance of the topic in understanding the history of life on Earth.

This section discusses Charles Darwin's concept of gradualism in evolution, which suggests slow and gradual changes over time. It contrasts this with the idea of revolutionary changes in the history of life. The paragraph describes the traditional Tree of Life, which shows a simple division between plants, animals, and other life forms, and how it has evolved into a more complex understanding, including the discovery of the three domains of life: bacteria, archaea, and eukaryotes.

The speaker delves into the importance of cellular energy flow in evolution, particularly focusing on the role of membrane electrical charge in powering life processes. He discusses the significance of this energy flow in the context of the history of life, questioning why it took billions of years for complex life forms to appear and how this energy perspective might offer new insights into evolutionary revolutions.

This section explores the impact of global cataclysms on the history of life, such as snowball Earth events and the Great Oxidation Event. It discusses how these events influenced the trajectory of evolution, particularly the emergence of eukaryotic cells, which marked a significant departure from the single-celled organisms that dominated Earth for billions of years.

The paragraph discusses the theory of endosymbiosis as a key event in the evolution of eukaryotic cells. It explains how one cell becoming internalized within another led to the development of complex cells with organelles, such as mitochondria. This process is considered revolutionary as it changed the cellular structure and the way energy is generated within cells, leading to the diversity of life we see today.

This section delves into the chemistry of cellular respiration, highlighting the importance of the electrical charge across membranes. It explains how this charge, equivalent to a bolt of lightning, is harnessed to generate energy through processes like the Krebs cycle and oxidative phosphorylation. The speaker emphasizes the universal conservation of this mechanism in all cells, suggesting it as a fundamental aspect of life's evolution.

The speaker discusses the Krebs cycle, a central metabolic pathway in cells that generates energy through the breakdown of organic molecules. He highlights the historical contributions of scientists like Hans Krebs and Marjorie Stephenson to our understanding of this cycle. The paragraph also touches on the spontaneous chemistry that occurs in prebiotic conditions, suggesting that the chemistry of life is older than the genes that encode it.

This section explores the hypothesis of the origin of life in alkaline hydrothermal vents, proposed by Mike Russell and discovered as Lost City hydrothermal vents. The speaker explains how these environments, with their electrochemical flow reactors, could have facilitated the emergence of life's building blocks through chemistry independent of genes. The structure of such vents is likened to that of cells, suggesting a commonality in the structure of life and Earth itself.

The speaker discusses the Cambrian explosion, a period marked by the rapid appearance of complex animals in the fossil record. He explores the role of oxygen in enabling higher trophic levels and the evolution of predation. The paragraph also touches on the Warburg effect, which describes how cancer cells revert to a more primitive metabolism, and the broader implications of understanding cellular metabolism in treating diseases like cancer.

In the concluding section, the speaker expresses gratitude to his lab team and funders for their contributions to understanding the history of life. He emphasizes the importance of considering the non-genetic aspects of life, such as metabolism and energy flow, in understanding evolution. The lecture ends with a reminder of the interconnectedness of life's processes and the ongoing scientific quest to unravel the mysteries of life's origins and evolution.