British biochemist Nick Lane's latest book might be less enigmatically titled “Everything you've ever wanted to know about mitochondria but were afraid to ask.” “Vital” here has a double meaning: it is the question of the origin of vitality, of life, and it is also the most important question we can ask if we are to understand life as we know it. And so the vital question is this: Why did complex (eukaryotic) life arise but once in the four billion-plus years of the Earth's evolutionary time frame?
To answer that question means starting at the very beginning, with the chemical formation of the first cell, most likely in the gently warmed bioreactors of deep sea alkaline thermal vents. Out is the famous “primordial soup” of the Miller-Urey experiments. Discounted are the glamorous, hot, and belching “black smokers” that have gotten all the publicity as the home of ancient bacteria. As Lane argues from his own research and that of others, it is all about energetics—the power of proton gradients—and those gradients most reasonably formed in the delicate percolating structures found in the towering alkaline vents of the deep.
Lane next tackles the question of why it then took over two billion years to forge a more complex, eukaryotic cell. As it turns out, this is all about bioenergetics as well. I'm reminded of that scene in the movie Apollo 13 where the NASA engineers brainstorm desperately to get their crippled spacecraft back from the moon. As arguments fly, one young engineer stands up and notes that the batteries on the ship are dying, and fast. “It's all about power,” he says. And so it is. Saving the crew means paying attention to power, because without it, everybody dies. The argument is the same here. In chapter 5, Lane provides the complex, exquisite argument of why mitochondria, and the power they generate, must necessarily have been at the heart of the formation of the eukaryotic cell. Yes, even before the nucleus.
The revelations do not end there. Origin of two sexes? Mitochondria. Finite lifespan? Mitochondria again. The arguments are compelling, drawn from decades of research by some of the brightest thinkers out there, but they are necessarily intricate. Such a story of complexity is not easily boiled down to a 30-second elevator pitch. And so the book is a challenging, if rewarding, read.
Lane opens the book by pitching it to the general reader, and states that he has hoped to avoid unnecessary jargon and entertainingly tell a most interesting story. I would agree that he has told a most interesting story—I would in fact characterize this compelling book as positively mind-blowing. Most readers of ABT have been out of school for at least a few years, and few are trained in evolutionary biology. Thus I suspect much of this engrossing tale of the chemical origin of the first cell, and the subsequent evolution of the complex eukaryotic cells, will be both novel and fascinating.
Still, there is no denying that this tale is not likely for the faint of heart, despite Lane's hopes of mass appeal. Indeed, it is a technical book that is probably well above the level of the lay reader. The discussion of proton gradients as central to cellular evolution (chapter 3), the energy-per-gene argument in eukaryotic cell evolution (chapter 5), and the discussions of the mitochondrial role in the origin of two sexes, fertility rates, and aging (chapter 6) are particularly challenging.
Nevertheless, for biology teachers and students entranced by the beautiful intricacies of cellular evolution, bioenergetics, life, sex, and death (and who among us at NABT is not?), this is a worthwhile read, of interest to biology educators wishing to update their understanding of research on the origins of life; it would also make an appropriate text for an upper-division or graduate seminar course on cellular evolution. Either way, Lane's book opens up in lively fashion the brave new world of evolutionary biology at its most fundamental: answering the burning questions about the very origins of life.