Amazon lists two versions of this book, with different subtitles: ISBN 0307378438, The Universe Within: Discovering the Common History of Rocks, Planets, and People is described as the first edition and is only available in hardcover. ISBN 0307473279, The Universe Within: The Deep History of the Human Body is offered in hardcover, paperback, and as an eTextbook. Both show as having 240 pages so the text is probably the same, and the subtitle was likely changed for some marketing reason after the book was originally published. The original subtitle describes the book much better than the second.
It is a good book, interesting, informative, and well written. It provides an introduction to the interconnectedness of cosmology, physics, geology, chemistry, and evolution, but only a few pages are actually about “the deep history of the human body.” The book is also short, with the main text coming in at under 190 pages. If this were fiction it would be a novella.
Shubin is best known for his book Your Inner Fish, which recounts finding Tiktaalik, a 375 million year old transitional fossil that shows how animals made the move from water to land. Remarkably, while the bones in our own hands and feet have been heavily modified over time, they are still recognizably the same anatomical structures as those of Tiktaalik.
He has a talent for presenting facts in memorable ways, such as “Hydrogen and helium today remain the most common elements in the universe. Hydrogen makes up about 90 percent of all matter, helium about 5 percent. All the others that compose us and run through the lives of people and stars are but a rounding error.” Similarly, in accounting for the creation of the heavier elements, everything up to iron can be forged in ordinary stars like our own, but “All the elements heavier than iron, such as the cobalt and cesium in our bodies, derive from supernovae.”
He can also provide logical and interesting explanations for things I had never thought about, as in “The gravitational pull of the sun meant that heavier material would orbit closer to it, while lighter particles and gas orbited farther away. To some extent, this state of affairs remains in effect today, with the solar system composed of rocky inner planets, Mercury, Venus, Earth, and Mars, and gaseous outer ones, Jupiter, Saturn, Uranus, and Neptune.”
Much of the book consists of one or two page biographical sketches of people who made important contributions to science, many of them revered in their field but unknown to most readers. The explanations of their work show the cumulative power of science, as one great idea builds on another. Of course, people being who they are, it was not a smooth ascent to ever greater knowledge. Some important ideas were ridiculed or ignored, and geology departments around the world almost went to war over plate tectonics, complete with underhanded sabotage of those with opposing views.
In order for life to have survived and evolved, the Earth had to maintain temperatures within a narrow range, but the sun has varied considerably over its life, “The sun is not a constant beacon of light; it started its stellar life as a relatively dim start over 4.6 billion years ago and has increased in brightness ever since, being about 30 percent brighter and warmer now than when it formed.” The key to maintaining life on Earth is carbon.
The planet’s temperatures are kept within a narrow range by the movement of carbon molecules through air, rain, rock, and volcano. Hot weather leads to more rock erosion, which leads to more carbon being pulled out of the air and thus colder weather. Then, just as things get colder, the cycle moves the planet’s temperatures in the opposite direction: colder weather leads to less erosion, increasing amounts of carbon in the air, and hotter temperatures.
There is an excellent discussion of how the 100,000 year ice age cycle was discovered, which was at first seemed a plausible but unconfirmed explanation, and it took decades before it was backed up with evidence from geology and ice cores. “Earth’s orbit changes in three major ways. Over 100,000 years Earth’s orbit goes from the shape of an oval to a more circular pattern. During 41,000 years Earth rocks back and forth about 2 degrees. And in the course of 19,000 years Earth’s tilt wobbles like a top.”
Having established how the Earth was formed and became hospitable for life, the book moves into evolution, again providing interesting observations, such as “no individual dwelling on Earth for the first 3 billion years was larger than a grain of rice.” Clear evidence of life goes back to 3.4 billion years ago, but it took a very long time for the first multicellular creatures to evolve. “The first 2.5 billion years of the history of [life on] the planet were entire devoid of big creatures; then, by about 1 billion years ago, there were not one but several different species with bodies populating the ancient seas: plant bodies, fungal bodies, and animal bodies, among others.”
In discussing the evolution of ever larger and more complex creatures, the author eventually gets to humankind. He makes an observation that contradicts other things I have read, that “DNA of Native Americans reveals that they are derived from a single male who likely crossed the Bering Strait when an ice bridge formed during the last ice age.” I accept that he is the expert here, but other studies indicate that people crossed the Siberian ice bridge for thousands of years, and it seems unlikely that all Native Americans could be traced back to a single individual unless the times scale is greatly enlarged, so that we are talking about a distant ancestor of everyone who once lived in Siberia, tens of thousands of years before the crossing of the Bering Strait.
Occasionally the author seems to remember the subtitle of the book, and inserts a fact that shows how today we are still connected with the cosmos, stretching back to the beginning of the Earth, and even farther “Whether originating from the ice of comets or vaporized from the rocky debris of the early solar system, or both, each glass of water we drink is derived from sources at least as old as the solar system itself.”
I enjoyed this book, and learned a lot from it, even though it is only occasionally about what the subtitle of the second edition says. And once again, it is much too short; it would have been better with another hundred pages of explanations and examples.