The Universe Within: Discovering the Common History of Rocks, Planets, and People

  • Neil Shubin
Pantheon: 2013. 240 pp. $25.95, £20 9780307378439 | ISBN: 978-0-3073-7843-9

Neil Shubin's masterpiece Your Inner Fish changed the way I see myself. Using evidence of the first fish-amphibians that left the oceans for land 375 million years ago, Shubin described with stunning clarity how every aspect of our anatomy goes back to our distant ancestors.

Now, in his follow-up The Universe Within, he takes the discussion a step further: how the Universe formed, our place in the Solar System and the intertwined evolution of our planet and life. He shows that all this is built into us as physical beings.

Inside us, for instance, are atoms that formed in exploding stars. The movements of heavenly bodies are inherent in our perception of time and in biological clocks. Physical parameters such as gravity determined our shapes and sizes. Had Jupiter formed closer to the Sun, we would have turned out short and squat; farther out and we would have been slender and elongated. This is because Jupiter formed before the inner rocky planets, and its position relative to the Sun determined Earth's size and gravity.

Shubin starts with the formation of the Universe 13.7 billion years ago, segueing into that of the Solar System 4.6 billion years ago. Much later, about 200 million years ago, when the supercontinent Pangaea broke up, the continents and ocean basins we know today began to form. This was accompanied by the rapid evolution of more complex life forms — dinosaurs, mammals and birds.

Shubin suggests a rather original connection between continental break-up and the evolution of such creatures: mud settling on the vast stretches of coastline created by the break-up of Pangaea buried biological material that would otherwise have decayed in water, using up oxygen. The result, Shubin says, was an increase in atmospheric oxygen, one of the key factors that allowed animals to conquer land. Mammals require a lot of oxygen to maintain their high-energy, warm-blooded lifestyle. Life on the low-oxygen Earth of 200 million years ago would have been like that today at 4,500 metres above sea level.

Much of the second half of The Universe Within summarizes the history of how our geological view of Earth developed. It incorporates stories such as how the discovery of similar fossil organisms on distant continents led Alfred Wegener and others towards the idea of continental drift. We also meet William Smith, who invented stratigraphy, Louis Agassiz, who discovered ice ages, and geologist Bruce Heezen and oceanographic cartographer Marie Tharp, who were central to developing the theory of plate tectonics.

Shubin is at his best when he deals with anatomy and biology, as in his discussion of the inventive geologist Michel Siffre. In 1962, Siffre spent two months living in a subterranean cave to gauge whether he could track time without any tools with which to measure it. After two months, he was convinced that only 37 days had passed. This was in line with what we know about the role in 'internal clocks' of the pineal gland, which regulates the production of sleep-inducing melatonin depending on the available light. Shubin's storytelling in such passages is gripping.

The Universe Within is a charming and enjoyable read, but it does not reach the heights of Your Inner Fish. There is a familiar feel to some of the sections, and the book's title raises expectations that are not really met. Where are the mysteries of the brain, the laws of thought and our consciousness? These, to me, are the most amazing aspects of the 'universe within'. In my view, the popular astronomy writer Timothy Ferris has touched on these aspects of the relationship between the soul and the Universe in a more thought-provoking way in books such as The Mind's Sky and The Whole Shebang.

The mystery of why we are here is perhaps greater than ever.

And what if our view of the Universe continues to change as much as it did in the past century? From Shubin, one gets the impression that much is now solved. But the mystery of why we are here is perhaps greater than ever. Maybe, as the physicist Max Planck put it: “Science cannot solve the ultimate mystery of nature. And that is because, in the last analysis, we ourselves are part of nature and therefore part of the mystery that we are trying to solve.”