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Chapter 20
Themes
Key
LitCharts assigns a color and icon to each theme in A Short History of Nearly Everything, which you can use to track the themes throughout the work.
Science, Discovery, and Mystery
Writing, Wonder, and Inspiration
Progress, Sexism, and Dogma
Existence, Awe, and Survival
Summary
Analysis
Most organisms—over 99.9 percent—decompose without a trace. From the remaining 0.1 percent, some will become fossilized, but only if the organism is buried in sediment without exposure to oxygen. If it’s left undisturbed for long enough, the organism’s bones can make an imprint on the sediment as it decomposes, which can become filled in by minerals as the rock is compressed over time. Fossils are extremely rare: Bryson estimates that only one in a billion bones ends up fossilized. Moreover, most land animals don’t die in sediments. In fact, 95 percent of fossils that humans have collected are from marine life that died in shallow seas. Our fossil records thus represent only the “merest sampling of all the life that Earth has spawned.”
Most of what scientists know about ancient life on Earth comes from fossils. The rarity of fossils—and particularly the extreme rarity of land-based fossils—shows that scientists have a severely limited and highly fragmented picture of Earth’s ancient species. Bryson emphasizes this to stress, once again, how little scientist know about the world around them (this time, ancient life), and how much knowledge about life in Earth’s history may inevitably evade us. Thus, there will always be a demand for scientists who to want narrow the gap between what we know and what we can never grasp about the past.
Themes
Bryson meets paleontologist Richard Fortey at the Natural History Museum in London, where Fortey shows Bryson a display of ancient “trilobite” fossils. Very little is known about these small marine animals except that they’re the earliest complex life forms we know of, they flourished suddenly during the “Cambrian explosion” 540 million years ago, and they vanished in a mysterious mass extinction 300,000 years later. Humans have only existed for 0.5 percent of that time. Little is known about early Earth’s evolutionary history until a paleontologist named Charles Doolittle Walcott discovers the “holy grail” of fossils.
While the sparsity of fossil evidence is a serious hindrance to scientific knowledge, scientists still struggle when evidence does surface—such as Walcott’s extraordinarily rare find of fossils from the Cambrian explosion—since there is still a wide margin for error in making sense of new evidence as it is discovered. Bryson further stresses that even with an abundance of evidence, there is a lot that scientists need to figure out.
Themes
During a trip in the Canadian Rockies in 1909, Walcott hikes up to the top of a hill and discovers a perfectly preserved 500-million-year-old fossil pit, now known as the “Burgess Shale.” It contains over 60,000 specimens from the Cambrian explosion. Sadly, the Burgess Shale goes largely unnoticed for over 70 years because Walcott under-describes the specimens as primitive ancient worm fossils in his writing. However, in 1973, graduate student Simon Conway Morris visits the Burgess fossils and is astounded to discover they are “far more varied and magnificent” than Walcott described.
Bryson raises another example of how uninspiring descriptions of scientific evidence hinder scientific progress. Walcott’s underwhelming descriptions of his find mean that scientists fail to fully address them for decades. Morris’s eventual analysis of the Burgess fossils once again shows that the more evidence scientists uncover, the more they are surprised by what they see.
Themes
Morris starts cataloguing the collection and discovers that these animals are unlike any others known to humankind—one species had five eyes and claws at the end of a long snout. Another scientist named Stephen Jay Gould suggests that the Cambrian explosion might have been a sort of “trial and error” experimentation period for early “body design.” Controversially, some scientists take Gould’s claim as evidence of creationism, believing that they’ve captured a maker experimenting with fully-formed life-forms before evolution proper kicked off.
The sheer strangeness of the Burgess fossils prompts speculation about what they mean. Bryson shows again that religious beliefs often intercept scientific progress. Here, religious biases prompt scientists to make problematically wild leaps that extend beyond the evidence in order to justify creationism.
Themes
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However, a British paleontologist named John Mason soon identifies a flatworm fossil specimen that predates the Cambrian explosion by 100 million years. Evolutionary theorist Dawkins argues that the flatworm fossil shows that the Burgess fossils evolved from earlier, simpler Precambrian life forms, thus proving that evolution (and not God) is responsible for them. Dawkins also argues that many of the Burgess fossils were assembled incorrectly, making them look stranger than they actually are. Bryson concludes that we may never solve the riddle of the Burgess fossils, since our entire knowledge of Precambrian life resides in a single fossilized fish specimen and we have no information about the gap between.
Bryson implies that the impetus among many scientists to confirm their religious biases can cause them to be hasty in making sense of new evidence. The Burgess fossils, for example, are assumed to be radically different than they actually are because many of them are assembled incorrectly. The incorrect assembly also shows how fallible and prone to error scientific claims are, while the relative lack of evidence means that insights into Earth’s early life forms remain a mystery that scientists have yet to solve.
Themes
