The Ancestor's Tale: A Pilgrimage to the Dawn of Life is a popular science book by Richard Dawkins and Yan Wong in which the history of life is retraced in reverse chronological order. A growing band of species meet their most recent common ancestors (concestors) at 40 rendezvous points. First published in 2004, it was updated in 2016 to reflect recent discoveries. Many reviewers described it as Dawkins's magnum opus.
Dawkins dedicated the book to John Maynard Smith: âÂÂHe saw a draft and graciously accepted the dedication, which now, sadly, must become In Memoriam.âÂÂ
The book is patterned on Geoffrey Chaucer's The Canterbury Tales, in which pilgrims on the road to Canterbury converge with other travelers and tell tales. Here, species convene with concestors, and "Canterbury" is the origin of life.
The epigraph is from Mark Twain: "History doesn't repeat itself, but it rhymes." The authors contend that âÂÂEvolution rhymes, patterns occur. And this doesn't just happen to be so. It is so for well-understood reasons: Darwinian reasons, mostly, for unlike human history or even physics, biology already has its grand unifying theory.â They emphasize that no living species is ancestral to any other, but that all share a common ancestor, some more recently than others. Evidence for this fact is that the genetic code for translating genes into proteins is universal. More closely related species have more similar genes and proteins. Genes and proteins act as molecular clocks that allow us to determine when species split. They use concestor, coined by Nicky Warren, to describe the most recent common ancestor at each rendezvous point.
The pilgrimage progresses through extant species, with a few exceptions: âÂÂAnimals such as the dodo, which survived into historical times and whose DNA is still available to us, are treated as honorary members of the modern fauna starting off on our pilgrimage. ⦠Since we are responsible for their recent extinction, it seems the least we can do. The other honorary pilgrims, exceptions to the rule that dead man tell no tales, really are men (or women). Since we human pilgrims are directly seeking our own ancestors, fossils that might plausibly be considered candidates for being our ancestors are deemed members of our human pilgrimage and we shall hear tales from these shadow pilgrims, for example the Handyman, Homo habilis.â The pilgrims do not speak in the first person, as the authors think that "twee."
The book was revised in 2016 in light of recent discoveries. Notably, The Denisovan's Tale replaces The Neanderthal's Tale and The Elephant Bird's Tale has been updated. The Mudskipper's Tale was present in the first edition but not the second. The Armadillo's Tale, about biogeography, is now The Sloth's Tale. In 2005, during a pilgrimage to the Galápagos, Dawkins wrote three new Tales. The third is reprinted in the second edition. The phylogenetic trees in the second edition are based on OneZoom evolutionary mapping software.
Each Tale illustrates an aspect of evolution. The Galápagos Finch's Tale is about natural selection, The PeacockâÂÂs Tale is about sexual selection, The SalamanderâÂÂs Tale is about speciation, and The BarnacleâÂÂs Tale is about how appearances can be deceiving.
From the lancelets onward, the authors provide dates under duress stating that "dating becomes so difficult and controversial that my courage fails me".
There are essential differences between the 1st and 2nd editions of the book in this section. Another rendezvous has been added (#33), and the unknown rendezvous has been partially resolved.
This is a significantly shorter section in the second edition. The authors describe the origin of eukaryotic (Greek, 'true nucleus)' cells and Lynn Margulis's endosymbiotic theory. Mitochondrion and chrloroplasts have their own DNA and divide by binary fission, like bacteria. Margulis surmised that this is because they are descended from free-living bacteria.
Prokaryotes (Greek, before kernel) lack a cell nucleus. They can move genetic material between unicellular and multicellular organisms via horizontal gene transfer.
The authors speculate about the origin of life, from Darwin's "warm little pond" through J. B. S. Haldane and Alexander OparinâÂÂs âÂÂprimordial soupâÂÂ, the MillerâÂÂUrey experiment and Spiegelman's Monster. In 1952, Stanley Miller and Harold Urey mixed methane, ammonia, hydrogen and water and sparked it with electricity. The product included seven amino acids, among them glycine, aspartic acid and alanine, among the twenty used to make proteins. In 1965, Sol Spiegelman seeded test tubes with enterobacteria phage Qbeta, and found it was subject to variation and selection. RNA can catalyze chemical reactions (like an enzyme) and store information (like DNA), indicating that it may have been the first replicator. The discovery of life near hydrothermal vents indicates that life may have begun deep underwater, or underground.
Dawkins, in the spirit of Stuart Kauffman, speculates on what would happen if evolution were âÂÂrerunâÂÂ. He notes that eyes have evolved as many as twenty times convergently. Several species have evolved gliding, including colugos, flying squirrels and sugar gliders. From so simple a beginning, flight has evolved at least four times in insects, pterosaurs, birds and bats. Echolocation has also evolved at least four times (in oilbirds, cave swiftlets, toothed whales and, again, bats).
However, as seen in âÂÂThe RhizobiumâÂÂs TaleâÂÂ, wheels seem to have evolved only once, in bacteria. Similarly, syntactic language seems to have evolved only once, in humans.
He concludes that science gives meaning to human existence: âÂÂNot only did evolution happen, it eventually led to beings capable of comprehending the process, and even of comprehending how they came to comprehend it.âÂÂ
Carl Zimmer of the New York Times wrote that it is one of the best books to understand evolutionary trees.
Rob Colwell of the Wall Street Journal called it "a fittingly superior beast -- lavishly produced and, weighing in at 1.6 kilograms, substantially heavier than the fully-evolved human brain that thought it up."
Clive Cookson of the Financial Times called it "one of the richest accounts of evolution ever written. It is also an object lesson in the way thorough picture research, carefully commissioned illustrations and good design can enhance even the best text." He adds "He is so good at explaining complex scientific issues that readers will learn painlessly about matters well outside the authorâÂÂs field of evolutionary biology, from maths to cosmology. But he interlaces the hard science with 'pleasing speculations', humorous asides, personal anecdotes and even political observations." He concludes "we have no right to expect a second magnum opus on the scale of The AncestorâÂÂs Tale."
Marek Kohn wrote "The success of this book comes from having one truly Chaucerian character: the author himself."
Robin McKie in The Guardian thought it awkward to move backward in time starting from humans and thought this required linguistic gymnastics. Matt Ridley, in the same publication, appreciated the approach of a Chaucerian Pilgrim traveling backwards and the perspective of not seeing other animals as failures.
Jody Hey notes that Dawkins âÂÂwrites engagingly on evolutionary topics. With a highly self-assured style, he effortlessly draws insightful connections among disparate notions, trapping the curiosity of readers before they know whatâÂÂs coming.â However, he says âÂÂAn unfortunate editorial oversight is seen in the textâÂÂs occasional straying into political commentary. Worse still, Dawkins at one point chastises Richard Lewontin, the great population geneticist, for sometimes interjecting politics into scientific discourse. This little touch of hypocrisy is hard to miss if you read the entire volume. But such lapses amount to a few dozen words in a weighty, truly wonderful book.âÂÂ
Steve Jones calls it âÂÂa rigorous and impressively complete account of the Tree of Life⦠The Ancestor's Tale achieves the almost impossible: it makes biology (not biochemistry, brain science, or bird-watching, but biology as a whole) interesting again. Everyone possessed of a cell nucleus should read it, and ponder their own unimportance. One mystery remains: what did the star-nosed mole say to the duck-billed platypus?âÂÂ