Remnants of Ancient Life: The New Science of Old Fossils
By Dale E. Greenwalt
Princeton University Press 2023

There’s a story in Dale Greenwalt’s book Remnants of Ancient Life: The New Science of Old Fossils, one of many: a modern human who researchers have named Otzi who lived thousands of years ago and died in a region that is now on the Austria-Italy border. He was a small, slight man, 5-foot-five, 135 pounds, and he was about 45 when he took a fatal arrow shot in the back. Greenwalt, the Resident Research Associate at the Smithsonian Institution’s National Museum of Natural History (he curates the museum’s huge collection of fossil insects), points out that the “proteome,” the suite of a Otzi’s proteins, is increasingly knowable by paleobiologists – enough for them to determine that in addition to that arrow wound, he’d also suffered a traumatic head injury. Greenwalt calls it “perhaps the coldest case ever solved.” 

Stories like that one, kernels for open-ended ‘what-if’ speculation, crop up throughout Greenwalt’s book, which centers on the exciting new work of those paleobiologists, who specialize in studying the traces of biomolecules that are found in fossils – proteins, DNA, chlorophyll, all kinds of living echoes that are yielding their secrets to newer and better analyses. “Taxonomic developments, determinations of sex, phylogenies, tooth development, and now a medical diagnosis: all based on ancient proteins,” Greenwalt writes.”The more fossils we find that contain preserved proteins, the more we will find out about the history of life on Earth.”

It’s all fascinating, an unabashedly excited report from the front lines, but these paleobiological strands aren’t the only joys of Greenwalt’s nerdy book. He consistently doles out thought-provoking nuggets on a wide variety of subjects. Sea turtle adaptations, for instance: “The hatchlings of most living species of sea turtles are known to rest on the water’s surface with their back exposed to the sun.  Laboratory experiments have shown that the sunlight absorbed by the darkly colored surface of the turtle’s back raises its body temperature,” he writes. “Tennis whites are white for a reason.” 

Or what it was like to see through dinosaur eyes: “Of all the vertebrates that lay eggs, birds are the only ones that produce colored eggs,” he writes. “If dinosaurs had brightly colored feathers and colored eggs, it is reasonable to assume that they could see colors.” 

This combination of startlingly precise new researches and terrific, grounded speculation is irresistible for the science geeks whose ranks Greenwalt proudly represents. Rocks are revealing new secrets; the past is changing; it’s all surprisingly exciting. 

Steve Donoghue is a founding editor of Open Letters Monthly. His book criticism has appeared in The Washington Post, The American Conservative, The Spectator, The Wall Street Journal, The National, and the Daily Star. He writes regularly for The Boston Globe, the Vineyard Gazette, and the Christian Science Monitor and is the Books editor of Georgia’s Big Canoe News.