The epigraph is from Mark Twain: "History doesn't repeat itself, but it rhymes." The authors contend that “Evolution 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.”^[4]: 1 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,^[4]: 11 to describe the most recent common ancestor at each rendezvous point.^[4]

It is patterned on Geoffrey Chaucer's The Canterbury Tales, in which travelers take turns telling tales. The pilgrimage progresses through extant species, with a few exceptions: “Animals 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.” The pilgrims do not speak in the first person, as the authors think that "twee."^[4]: 10

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, Dawkins wrote three tales during a pilgrimage to the Galápagos.^[5][6][1] The third is reprinted in the second edition.

Each Tale illustrates an aspect of evolution. “The Galapagos Finch's Tale” is about natural selection, “The Peacock’s Tale” about sexual selection, “The Salamander’s Tale” about speciation, “The Barnacle’s Tale” about how appearances can be deceiving.

Dawkins dedicated the book to John Maynard Smith.

Rendezvous point	Time	New Pilgrim	Story
1	6 mya	Chimpanzees	The Chimpanzee's Tale is about the comparison of human and chimpanzee genomes. The authors note that human chromosome 2 formed from a recent fusion, which is why the other great apes have 24 pairs of chromosomes and humans have 23.[8][9] (See also Chimpanzee–human last common ancestor.) The Bonobo's Tale is about incomplete lineage sorting.
2	7 mya	Gorillas	The Gorilla's Tale considers human's changing attitude towards the great apes, ending with a discussion on racism, speciesism and the Great Ape Project. (See also Gorilla–human last common ancestor.)
3	14 mya	Orangutans (Pongo)	The Orangutan's Tale introduces the principle of parsimony and its use in construction of family tree (cladogram) of species. Orangutan is the last of the great apes to join the pilgrimage. (See also Orangutan–human last common ancestor.)
4	18 mya	Gibbons (Hylobatidae)	The Gibbon's Tale is about phylogenetics. The authors note that the genetic code is degenerate. As a result, “some DNA codes are synonymous: they specify exactly the same amino acid.”[4]: 158  Synonymous substitutions are invisible to evolution but not to biologists. Since they are not subject to selection, they show greater variation between species. The same is true of pseudogenes. Coding regions are conserved sequences. Rare genomic changes are unlikely to have arisen independently, and are likely due to common descent. The authors note that “literary scholars use the same techniques as evolutionary biologists in tracing the ancestries of texts. And – almost too good to be true – one of the best examples happens to be the work of the Canterbury Tales Project.”[4]: 159  Gibbon is the last ape to join the pilgrimage. (See also Gibbon–human last common ancestor.)
5	25 mya	Old World monkeys (Cercopithecidae)	Old World monkeys, being in the same Catarrhini clade as apes, are closer cousins to apes than to New World monkeys. Old World monkeys are sometimes called the 'tailed apes'. It is not known if the actual common ancestor had a tail or not.
6	40 mya	New World monkeys (Platyrrhini)	The Howler Monkey’s Tale is about gene duplication and how it creates new genes. When a gene is copied, it can evolve a new function. This happened in the evolution of color vision in primates. Old World Primates (including humans) are trichromats, with three opsins (red, green and blue), each coded for by a specific gene. The red and green opsin genes are similar, and adjacent on the X chromosome. They are derived from a recent duplication. Mutations that improved the function of the new gene were selected for until the opsin could detect a different wavelength. Most New World monkeys are dichromats, with either red or green genes on the X chromosome (a polymorphism.) In Howler monkeys, both genes were put on the X chromosome through a translocation. As often happens in evolution, the same end was reached via a different means.
7	60 mya	Tarsiers	The Tarsier's Tale is about its enormous eyes. Unlike most nocturnal mammals, they lack a tapetum lucidum to reflect light from the back of the eye for a second exposure on the retina. The ancestor of the tarsier was a diurnal animal which lost the tapetum lucidum. In 2013, Archicebus, the oldest primate fossil found so far, was discovered in China.[10]
8	65 mya	Lemurs and Bushbabies	The pilgrimage meets with the rest of the strepsirrhine cousins: the lemurs, pottos, bushbabies, and lorises. The Aye-Aye's Tale is about island ecology. In Madagascar, a small founding population of strepsirrhines evolved to fill available niches. Today, it is home to as many as one hundred species of lemur. The authors quote Douglas Adams on the aye-aye: “Like virtually everything else on Madagascar, it does not exist anywhere else on Earth.”[4]: 199  Madagascar is also home to six of the world’s eight species of baobabs. With a landmass 1/1000 of Earth's total land area, it accounts for 4% of all species of flora and fauna.

Rendezvous point	Time	New Pilgrim	Story
16	320 mya	Sauropsids	"Reptile" is not a true clade name. Dinosaurs, unfortunately extinct, are joined by their only surviving descendants, the birds.
			The Lava Lizard's Tale is about geology. Dawkins describes his pilgrimage to the Galápagos island of Santiago, visited by Darwin in 1835. A volcano erupted there one day in 1897. The events of that day are written in the island’s rocks, and we can read them. Dawkins describes the unique flora and fauna of the archipelago, and the camouflage used by the lava lizard.
			The Galapagos Finch’s Tale is about natural selection and how it can produce rapid evolutionary change. Peter and Rosemary Grant have found this through their long-term study of Darwin’s finches. In 1977, the island of Daphne Major was struck by drought, which created selective pressure for longer beaks capable of cracking the tough seeds of Tribulus: “The average beak length after the drought was 11.07 mm long compared with 10.68 mm before. The mean depth of beak had similarly gone up from 9.42 to 9.96.”[4]: 313  In 1982-1983, there was a flood brought about by El Niño. The selective pressure changed to favor smaller beaks that could eat the smaller seeds of Cacabus. The finches again evolved accordingly. In 2015, the Grants, along with researchers at Uppsala University, “located a number of DNA regions that co-varied with beak shape and homed in on a gene called ALX1… The ALX1 gene tree, deduced from Galapagos finch populations, shows branching patterns indicative of natural selection.”[4]: 315 [12]
			The Peacock's Tale is about sexual selection and how it can produce rapid evolutionary change. The peacock's plumage evolved because generations of peahens preferred plumage. R. A. Fisher found that genes making males have a trait are linked to genes for females preferring that same trait, leading to runaway evolution. Dawkins describes this in The Blind Watchmaker.
			The Dodo’s Tale is about island biogeography. Many birds colonizing oceanic islands convergently evolve flightlessness. Since these islands lack predators, wings aren’t selected for, and become vestigial. This happens even if wings would be useful in the future. This was sadly true in the case of the dodo, as wings would have proved useful when men arrived in Mauritius with clubs. On a happier note, biologists led by Alan Cooper have analyzed mitochondrial DNA from dodo specimens, and found they were related to pigeons.
			The Elephant Bird's Tale is about island gigantism. Many species colonizing oceanic islands evolve rapidly in size, as seen in the extinct elephant bird of Madagascar and the moa of New Zealand. In the first edition, Dawkins speculated that extant ratites (rheas of South America, emus of Australia, cassowaries of Australia and New Guinea, kiwis of New Zealand and the ostrich, now of Africa) evolved flightlessness convergently rather than inheriting it through a single flightless ancestor. Molecular evidence, from Cooper’s study of Elephant Bird DNA, confirms this.[13]
17	340 mya	Amphibians	Mammals and reptiles (the amniotes) join the amphibians to meet the ancestor of all land vertebrates with four feet, the tetrapod. Amphibians include frogs, toads, salamanders, newts and caecilians. While amniotes either give live births or lay waterproof eggs, the amphibians retain the ancestral practise of laying eggs in water. Unlike the waterproof skin of amniotes, the amphibian skin allows body water to evaporate through it, restricting amphibians to land areas with access to fresh water. Almost no amphibians live in saltwater which explains why they are seldom found on islands. The concestor probably already had settled on five digits on each limb.
			The Salamander's Tale is about speciation. When a species inhabits a geographic ring, “there is potentially gene flow around the ring. Potentially.”[4]: 343-344  Robert C. Stebbins studied the Ensatina salamanders, which inhabit a ring surrounding California’s Central Valley. Around the ring, neighbouring populations of Ensatina can interbreed. But the plain Ensatina eschscholtzii on the western end cannot interbreed with the blotched Ensatina klauberi on the eastern end. Moving westward round the ring, populations become progressively plainer until they resemble Ensatina eschscholtzii. Moving eastward, populations become gradually more blotched until they resemble Ensatina klauberi. The authors write that ring species “are only showing us in the spatial dimension something that must always happen in the time dimension.”[4]: 346
			The Narrowmouth's Tale is about parapatric speciation. Gastrophryne olivacea (Great Plains narrow-mouth toad) and Gastrophryne carolinensis (eastern narrow-mouth toad) are closely related. The most noticeable difference is in their mating calls. The former species has adapted to the western United States, the latter the eastern. But their ranges meet in the middle. It is there that their mating calls differ most sharply. Theodosius Dobzhansky theorized that this was due to reinforcement: natural selection favours adaptations that make interbreeding less likely. This causes character displacement, where two related species differ more in areas where they overlap.
			The Axolotl's Tale is about metamorphosis, by which larvae change into dramatically different adult forms for reproduction. A frog has genes for making a tadpole. John Gurdon dramatically demonstrated this in 1962 by transplanting the nucleus of an adult frog into an enucleated cell, which developed into a tadpole. This work won him the Nobel Prize in Physiology or Medicine in 2012. Most salamanders undergo metamorphosis. They pass through a larval stage with “long, feathery external gills” which they lose as adults. Axolotls exhibit pedomorphosis, a process which enables juveniles to become sexually mature without developing into their usual adult forms. Axolotls remain aquatic and retain the gills. Julian Huxley found that with a treatment of thyroxine, it is possible to induce an axolotl to develop into a mature salamander. On the other hand, the newt first develops from tadpole into a land-based salamander, but later reverts to its juvenile form, returning to the water to reproduce.
18	415 mya	Lungfish (Dipnoi)	Despite their morphological similarities, the lungfish and coelacanth are very different genetically, as expected of species which lived separately for more than 400 million years. One lungfish has the record for largest genome at 133 billion base pairs compared to our 3 billion base pairs.
			The Lungfish's Tale is about the evolution of tetrapods. The authors trace transitional fossils documenting this transformation: Eusthenopteron, Panderichthys, Tiktaalik, Acanthostega and Ichthyostega. They speculate about selection pressures might that drove fish to land. For many years, the favored idea was that of Alfred Romer, that fish who could move from a drying pond to a deeper one had an advantage. Among the six extant species of lungfish, the South American lungfish (Lepidosiren paradoxa) and four species of African lungfish (in the genus Protopterus) do something similar today, using their lungs to make it through dry seasons. (The Australian lungfish, Neoceratodus forsteri, inhabits weedy waters and uses its lung to supplement its gills.) But the Devonian does not seem to have been defined by drought, and Romer’s idea has fallen out of favor. But Steven Balbus notes that Earth’s moon was once much closer, and its tidal forces much stronger. It is possible that this concestor was moving from tide pool to tide pool. (There are other reasons to come to land. Mudskippers feed on land, and some spend more time on land than in water). The lungfish’s eponymous organ is likely homologous to ours, inherited from concestor 18.
19	420 mya	Coelacanths (Latimeria)	The Coelacanth's Tale is about so-called “living fossils”, of which the coelacanth is a celebrated example. The authors describe its discovery by Marjorie Courtenay-Latimer. However, even species that show little phenotypic change undergo molecular evolution, as revealed by genetic analysis. The reasons are seen later in the pilgrimage.
20	430 mya	Ray-Finned Fish (Actinopterygii)	The current pilgrimage consisting of all descendants of lobe-finned fish is joined by the equally successful ray-finned fishes which includes sturgeon, paddlefish, eel, herring, carp, salmon, trout, seahorse, cod, etc. to meet concestor 19, the bony fish. Of all ray-finned fishes, by far the most belong to the infraclass teleostei (Greek, complete bone).
			The Leafy Sea Dragon's Tale is about the plasticity of animal forms. Evolution has molded many teleosts into strange shapes. The leafy sea dragon hangs motionless among kelp, which it resembles. Shrimpfish have been elongated to resemble strands of seaweed. The snipe eel has been stretched, while the gulper eel sports grotesquely large jaws. The ocean sunfish, weighing up to two tons, resembles a vast disc or millstone, as its Latin name, Mola mola, suggests. Teleosts can control buoyancy because of a unique adaptation, described in the next tale.
			The Pike's Tale is about the evolution of the swim bladder. Contrary to common belief, it is not the progenitor of the lung. The bony-fish ancestor possessed a primitive lung which, in teleosts, was co-opted as the swim bladder, used to maintain hydrostatic equilibrium. In some teleosts, it is used as resonating device. Such exaptation is common in evolution.
			The Cichlid's Tale is about adaptive radiation. Cichlids in the African Great Lakes have fast formed new species. Lake Victoria, about 100,000 years old, has as many as 450 cichlid species. Lake Victoria cichlids are distinct from Lake Malawi cichlids which are distinct from Lake Tanganyika cichlids. Yet within each lake, similar adaptations have convergently evolved. The authors quote George W. Barlow on the cause of speciation: “Genes flow but not much.” In allopatric speciation, a physical barrier disrupts gene flow, one reason islands have been so important in evolution. But any isolated environment could be considered an island. To a fish, a lake is an island, if not an archipelago (since not all parts are equally habitable.) A reef (defined by the Oxford English Dictionary as ‘a narrow ridge or chain of rocks, shingle, or sand, lying at or near the surface of the water’) within the lake could be an ‘island’. Indeed, genes seem to flow within reefs but not between them. The authors recount how, by constructing an "unrooted haplotype network" with computational phylogenetics of mitochondrial DNA, Erik Verheyen, Walter Salzburger, Jos Snoeks and Axel Meyer were able to infer the time and the location of each major speciation event. Geologic evidence shows that Lake Tanganyika was once split into three lakes. Genetic evidence shows splitting into three species around the same time. All the species are ultimately derived from a single species flock from Lake Kivu. As in The Galapagos Finch’s Tale, different lines of evidence corroborate one another.[14]
			The Blind Cave Fish's Tale is about Dollo's Law that evolution cannot be reversed. An exception seems to come from species living in caves. Many species, having colonized caves, have convergently evolved similar adaptations, including the loss of skin pigmentation and eyes. Different populations of Mexican tetra (Astyanax mexicanus) have separately ventured into caves, and each has evolved white skin and blindness. This can be explained by opportunity cost: resources spent on building eyes cannot be used for other things. In a cave, resources spent on eyes can be used for things more useful in that environment, and the eyes become vestigial. Another possibility is that, in the absence of selective pressure, deleterious mutations accumulate. Eyes won’t be selected for if they’re not useful in the present, even if they may be in the future. Natural selection is blind.
			The Flounder's Tale is about how evolution tinkers with existing body plans. When flatfish hatch, they are symmetric, with an eye on either side. But evolution has fashioned them for a life lying flat on the ocean floor. During development, the eye on the lower (blind) side migrates to the upper side. This happens whether they lie on their left (plaice) or right (turbot). This asymmetry results in distortions in the skull. Dawkins discussed this in his Royal Institution Christmas Lectures, on “Designed and Designoid Objects.”[15]
21	460 mya	Sharks (Chondrichthyes)	Sharks, rays and the related animals are supported by a cartilaginous skeleton that never ossifies to become bone. Their skin is covered in dermal denticles, tiny scale-like protrusions, from which teeth may have evolved. Sharks lack a swim bladder for buoyancy and instead rely on constantly swimming, retaining urea in their blood, and having large livers with plenty of oil to remain afloat. Concestor 21 was an ancestor to all gnathostomes, animals with lower jaws, a structure which evolved from the gill arches.
22	525 mya	Lampreys and Hagfish (Cyclostomata)	Jawless and limbless fishes, the lampreys and hagfish, join the pilgrimage to meet the concestor of all vertebrates. The jawless fish and the concestor 22 are borderline vertebrates. Unlike the rest of vertebrates, they retain the notochord, a stiffening cartilage rod running along the back of an animal, well into adulthood. In all other vertebrates, the vestigial notochord appears in the embryo briefly and is replaced by segmented, articulate backbones in adults. On the other hand, both the jawless fish and the jawed fish share characteristics common to all members of the phylum Chordata at some time in their life cycle, including the notochord, pharyngeal slit, and the post-anal tail.
			The Lamprey's Tale is a variation on the theme of “The Howler Monkey’s Tale”, about how gene duplication creates genetic novelty. In vertebrates, haemoglobin, the protein that carries oxygen in the blood, is composed of four globin chains, two alpha and two beta. The genes coding for haemoglobin are paralogous, derived from duplication. (In humans, they are coded for by gene clusters on chromosomes 11 and 16, respectively.) An ancestor globin gene from an ancient vertebrate split into two genes, which ended up on two different chromosomes. Both alpha and beta further split into more independently evolving genes. We can make a prediction: Lampreys and hagfish are ancient and predate this gene split. Jawless fish should not possess split globin genes. But they should be present in the genomes of bony fish, amphibians, reptiles, birds and mammals. That is what is found.
23	535 mya	Sea Squirts (Urochordata)	The lancelet and sea squirt have been switched in the second edition based on DNA studies. A sea squirt resembles a sedentary bag of seawater anchored to a rock. It feeds on food particles strained from water. Anatomically, the sea squirt looks very different from the joining pilgrimage of all vertebrates and protochordates, that is, until its larvae are examined. The sea squirt larva looks and swims like a tadpole. It possesses a notochord and a dorsal nerve tube and moves by undulating its post-anal tail from side to side. Vertebrates may have branched off from ancient sea squirt larvae via neoteny, in a process reminiscent of The Axolotl's Tale. But recent DNA analysis on larvaceans favours Darwin's initial interpretation, that one branch of ancient tadpole-like protochordates evolved a new metamorphosis stage to turn into sedentary sea squirts. Sea squirts have some of the fastest recorded rates of molecular evolution.
24	540 to 775 mya	Lancelets (Amphioxiformes)	Lancelets are a text book example of a chordate. Equipped with a notochord, a nerve tube on the dorsal side and gill slits, they typify the phylum Chordata. But lancelets are not primitive nor our remote ancestor. They are as modern as all other members in the pilgrimage.
			The Lancelet's Tale continues to develop the theme introduced in The Duckbill's Tale, that all living animals have had equal time to evolve since the first concestor, and that no living animal should be described as either lower or more primitive. The authors extend this concept to apply to fossils as well. Even though it is tempting to label fossils as our remote ancestor, they are more accurately described as our distant cousins who have been frozen in time.

From the lancelets onward, the authors provide dates under duress stating that "dating becomes so difficult and controversial that my courage fails me".

Rendezvous point	Time	New Pilgrim	Story
25	550 mya	Ambulacrarians	This diverse group includes the echinoderms, along with some organisms labelled "worms" and even Xenoturbella, which until 2016 could not be classified at all, but analysis of its genes finally established its position as a distant relative of the echinoderms.[16][17]
26	560 mya	Protostomes	The protostomes join the deuterostomes, and this joint is the originator of the kingdom Animalia. Protostomes (meaning 'mouth first') and deuterostomes (meaning 'mouth second') are based on the way animal embryos diverge after gastrulation where the blastula (a hollow ball of cells) indents to form a cup. In the sub-kingdom of protostomia, the indentation eventually becomes the mouth. In deuterostomia which includes humans, the indentation eventually becomes the anus; the mouth is formed later. This ancestor is sometimes referred to as Urbilaterian. This brings in the Insecta which represent three-quarters of all animal species on Earth.
			The Ragworm's Tale is about the evolution of left-right symmetry in bilaterians. Dawkins discusses the evolution of eyes, thought to have happened as many as 40 times convergently. Despite the diversity of eyes, the same genes control their development in different species, for reasons seen in The Fruit Fly's Tale.
			The Brine Shrimp's Tale is about its proclivity for swimming upside down, which it shares with fairy shrimp. Dawkins suggests that natural selection favors individuals who learn a behavior, and that genes “catch up.” He asks how it is that animals come to distinguish up from down. It seems to be an instinct, as Dawkins’s graduate work showed. The moral of the story is that evolutionary changes may start as learned behaviors that are reinforced by natural selection.
			The Leaf Cutter's Tale is a variation on the theme of the Farmer’s Tale. Fungus-growing ants of the genus Atta independently invented agriculture, long before humans, by domesticating fungi and harvesting their gongylidia. Several species of ants have independently domesticated aphids. The moral of the story is delayed gratification as the basis for agriculture.
			The Grasshopper's Tale talks about the futility of discriminating between races.
			The Fruit Fly's Tale is about embryology. It is a variation on the theme of The Mouse’s Tale, about how genes control development. A handful of Hox genes control development in almost all animals. The body plans of mice, men and fruit flies are found in Hox genes, laid down in the same order on chromosomes in all species since Concestor 26.
			The Rotifer's Tale is about the evolution of sex. The bizarre bdelloid rotifer reproduces via parthenogenesis. Through mitosis, they produce eggs which yield genetically identical daughters. Mark Welch and Matthew Meselson have found that rotifers have been asexual for millions of years. John Maynard Smith called this “an evolutionary scandal.” The authors write that sex may be the real scandal. Why do we do it? One answer comes from the Red Queen hypothesis, that organisms are engaged in an evolutionary arms race against parasites. Sex (specifically, recombination during meiosis) creates the variation that is the raw material for natural selection.
			The Barnacle's Tale is about how appearances can be deceiving, as Darwin discovered through long study. Barnacles, as their larva stage reveals, are crustaceans. Perhaps the most bizarre barnacle is Sacculina, which is as a parasitic castrator of crabs.
			The The Velvet Worm's Tale is about the Cambrian explosion. In the epilogue, the authors expound on the molecular clock method used throughout the book, Motoo Kimura's neutral theory of molecular evolution and Tomoko Ohta's nearly neutral theory of molecular evolution. As seen in The Gibbon's Tale, the genetic code is redundant, as many codons code for the same amino acid. A synonymous substitution will be invisible to natural selection but not to biologists..
27	570 mya	Acoelomorph Flatworms	Still under debate on how this group fits in due to a long period of molecular evolution similar to the Gibbons Tale. These flatworms lack an anus or a coelom. The organs do not sit in a coelom but a parenchyma and is the reason for the name of the group.
28	590 mya	Cnidarians	The Jellyfish's Tale discusses how some underwater organisms migrate between different depths due to day and night cycles.
			The Polypifer’s Tale is about the formation of coral reefs. Corals are symbionts with zooxanthellae, photosynthetic algae, and as such grow in shallow waters. How do barrier reefs form in deep ocean? Darwin discussed this in his first scientific book, The Structure and Distribution of Coral Reefs. He suggested that the seafloor subsided. His theory still stands, and the subsidence is explained by plate tectonics.
29	600 mya	Ctenophores (Comb jellies)	It is not completely clear whether Ctenophora should be placed here as an outgroup to all animals and actually at rendezvous 31. But this would mean that they either independently invented muscle, nerves, cell layers or that the sponges lost them: only 100 species but quite numerous. DNA studies are also complicated by incomplete lineage sorting like with the Gibbon.
30	620 mya	Placozoans	Only one species identified. It looks like a multicellular amoeba.
31	650 mya	Sponges	The last animal of the chain. Do not move but have a coordinated movement between cells. Also, seems to be two lines of sponges based on molecular data. Sponge cells are totipotent.
			The Sponge's Tale is about multicellularity. In 1907, Henry Van Peters Wilson separated a sponge into its component cells with a sieve. The sponges reassembled themselves. The authors suggest this sheds light on the origin of metazoans.

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 critical beginnings of eukaryotic cells and describe the endosymbiotic theory proposed by Lynn Margulis.

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 Oparin’s “primordial soup”, the Miller–Urey 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 “rerun”. 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 “The Rhizobium’s Tale”, 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: “Not only did evolution happen, it eventually led to beings capable of comprehending the process, and even of comprehending how they came to comprehend it.”^[4]: 699

Carl Zimmer of the New York Times stated that the book is one of the best to understand evolutionary trees.^[18]

The Guardian thought it was awkward to move backward in time starting from humans and thought this required linguistic gymnastics with new definitions of before and after a certain evolutionary point.^[19] 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.^[20]

Jody Hey notes that Dawkins “writes 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 what’s coming.” However, he says “An unfortunate editorial oversight is seen in the text’s 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.”^[21]

Steve Jones calls it “a 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?”^[3]

• Evolutionary history of life
• Phylogenetic tree
• Timeline of evolution
  • Timeline of human evolution