The Enigma of Life’s Origin : The Story of a Cells’s Birth

"If life is nothing but an electron looking for a place to rest, death is nothing but that electron come to rest."

About a year ago, I came across DeepMind’s Alphafold, the deep learning based algorithm that outperformed other teams in solving biology’s grandest challenge - determining a protein’s 3D shape from its amino-acid sequence. Although, the features in the dataset were biology jargons to me, the deep learning based algorithm was familiar ground. I thought what better way to acquaint myself with the world of cells than to read Nick Lane’s book – The Vital Question. It was also recommended on the Lex Fridman podcast. Little did I know, this book meant for casual reading was actually scientifically pretty dense. But I still managed to understand most of it because of its engaging narrative. Certain explanations had me spellbound.

The protagonist of the story are the prokaryotes, set against the thermodynamic soup, our planet being a rich broth of reactive gases, fluids, thermal vents. He vividly details all the happy accidents like explosions, glaciations, and more environmental upheavals that might have led to the evolution of prokaryotes.

“Rock, water and CO2 : the shopping list of life. We will find them on practically all wet rocky planets. By the rules of chemistry and geology, they will form warm alkaline hydrothermal vents, with proton gradients across thin-walled catalytic micropores. We can count on that. Perhaps their chemistry is not always conducive to life. Yet this is an experiment going on right now, on as many as 40 billion earth-like planets in the Milky Way alone. We live in a cosmic culture dish. How often these perfect conditions give rise to life depends on what happens next.”

So how could a cell be built from scratch? That’s the first quarter of the chapters. Why the structural complexity of life came to be the way it is and not any other number of ways it could have been, why do all living organisms have sex and age the way they do? Nick Lane speculates the answers to all the vital questions lies in energy - ATP synthase, the turbine that generates energy in cells is an exchange of electrons and protons at its core, also known as mitochondria.

The book further delves into mitochondria’s role in our DNA and genes. And how natural selection played a role in that. This excerpt from the book tied in mitochondria and the familiar Darwin's theory of natural selection, neatly.

"Selection is blind and merciless. Genes are continuously transferred from the mitochondria to the nucleus. Either the new arrangement works better, and the gene stays in it's new home, or it does not, and some penalty is exacted- probably death. In the end, nearly all the mitochondrial genes were either lost altogether or transferred to the nucleus, leaving a handful of critical genes in the mitrochondria. This is the basis of our mosaic respiratory chains - blind selection. It works. I doubt that an intelligent engineer would have designed it that way; but this was, I hazard, the only way that natural selection could fashion a complex cell, given the requirement for endosymbiosis between bacteria."

Wow, life in this primordial soup feels exciting reading about the wondrous mysteries of cells. Overall a solid attempt at making the layman understand the passionate bold ideas about the meaning of "life".