The Ancestor's Tale: A Pilgrimage to the Dawn of Evolution by Richard Dawkins with additional research by Yan Wong Houghton Mifflin Company, Oct. 2004 673 pages, hardcover Review by Jim Walker
The title derives from an allusion to Geoffrey Chaucer's Canterbury Tales, where the characters tell tales on their way backward to ancient Canterbury picking up pilgrims along with way at various rendezvous points. Dawkins Canterbury represents the origin of life, the oldest ancestor to our unbroken heritage. The pilgrims in Dawkins story describe our cousins the chimpanzees, gorillas, primates, mammals, animals, etc. The 'beginning' starts with us, the human beings, and the story goes backward in time, following the long branching tree of evolution from the outermost twig, the branches, the trunk, and finally to the root of all life.
Dawkins has a very good reason for describing the evolutionary path backwards rather than forward. Many laymen evolutionists (and religionists) have incorrectly concluded that evolution progresses linearly and has a purpose where we humans act as the target for a 'higher' form of evolution. If one looks at evolution in the direction of forward time, it can lead one to this false sense of progress. Because of Dawkins disavowal of aimed evolution, he chose to do history backwards to avoid this misconception. And it works. Looking at evolution backwards gives us a novel and new appreciation for the diverse and branching aspect of evolution. At each branch point (rendezvous point) we meet our ancestors (Dawkins invents the term concestors). The first rendezvous point, for example, examines our first cousins the chimpanzees, our closest relatives on the DNA chain. This backward way of looking at evolution shows us that humans did not evolve from chimpanzees but rather we evolved out of a shared concestor which gave rise to chimps and humans. A major rendezvous occurs with rendezvous 26 (about 590 million years ago), when all the insects, molluscs, and the worms join. Then we go on to meet the fungi, the plants and eventually the bacteria at some indeterminate time in the ancient past, where all life shares the same ancestor. It takes only 40 rendezvous points to travel back to the beginning of life on earth itself. This appears breathtaking when one considers that all living things trace their lineage back to a single ancestor, a bacterium that lived more than three billion years ago. All life as we know it consists of DNA and all living things, including bacteria, share common genes.
Dawkins describes the latest cutting edge ideas of evolution that includes theories about the emergence of bipedalism, the wrongheaded idea of primitiveness, and evolutionary measurement clocks (tree rings, radioactive dating, DNA code comparisons, and Bayesian analysis, etc.). We learn about ring species (that blows the creationist 'no evidence of transitional specie' falsehood out of the water) hox genes, and junk DNA.
As we can expect, Dawkins argues against the creationists and presents a compelling case against the supernatural explanation for life. Dawkins really shines when he exposes a falsehood which he describes as "The tyranny of the discontinuous mind," whereby certain people think in absolutist terms trying to fit unclassifiable things into classifications (and thus producing reification fallacies). Dawkins realizes the importance of exposing these falsehoods because they form the major reason for the misunderstanding of evolution.
Lots of names will seem strange for those not familiar with biological labeling (Ergasts, Xenarthrans, Tetraconata, Amoebozoa, Ecdysozoa, Oomycota, Neomeniomorpha, for example) but this only adds to the mystery of diversity of life. This ambitious book gets complicated in parts (for us laymen) and even though it has over 600 pages, the travel has it rewards. It will reveal, like no other book on evolution, the complexity, diversity, and wonderment of life on earth.
A few quotes from the book:
Biological evolution has no privileged line of descent and no designated end.
The evidence is that all that have ever been examined share (exactly in most cases, almost exactly in the rest) the same genetic code; and the genetic code is too detailed, in arbitrary aspects of its complexity, to have been invented twice.
As things stand, it appears that all known life forms can be traced to a single ancestor which lived more than 3 billion years ago.
In spite of the fascination of fossils, it is surprising how much we would still know about our evolutionary past without them. If every fossil were magicked away, the comparative study of modern organisms, of how their patterns of resemblances, especially of their genetic sequences, are distributed among species, and of how species are distributed among continents and islands, would still demonstrate, beyond all sane doubt, that our history is evolutionary, and that all living creatures are cousins. Fossils are a bonus. A welcome bonus, to be sure, but not an essential one.
Written records are more reliable than oral tradition, by a disconcerting margin.
Frustratingly, oral tradition peters out almost immediately, unless hallowed in bardic recitations like those that were eventually written down by Homer, and even then the history is far from accurate. It decays into nonsense and falsehood after amazingly few generations.
We don't need fossils to peer back into history. Because DNA changes very slowly through the generations, history is woven into the fabric of modern animals and plants, and inscribed in its coded characters.
Human and chimpanzee DNA are so similar, they are like English spoken in two slightly different accents. The resemblance between English and Japanese, or between Spanish and Basque, is so slight that no pair of living organisms can be chosen for analogy, not even humans and bacteria. Humans and bacteria have DNA sequences which are so similar that whole paragraphs are word-for-word identical.
A stunning conclusion is that, for particular genes, you are more closely related to some chimpanzees than to some humans. And I am closer to some chimpanzees than to you (or to 'your' chimpanzees).
We must not assume, as many laymen do, that our ancestors were chimpanzees. Indeed, the very phrase 'missing link' is suggestive of this misunderstanding.
Molecular evidence suggests that chimpanzees and bonobos are more closely related to humans than they are to gorillas. From this it follows that humans are exactly as close to gorillas as chimpanzees and bonobos are. And we are exactly as close cousins of orang utans as chimpanzees, bonobos and gorillas are.
To call a gorilla or a chimpanzee a monkey is a solecism.
Gibbons are faithfully monogamous, unlike the great apes which are our closer relatives. Unlike, indeed, the majority of human cultures, in which custom and in several cases religion encourages (or at least allows) polygyny.
About half of human DNA consists of multiple copies of meaningless sequences.
Fascinatingly, literary scholars use the same techniques as evolutionary biologists in tracing the ancestries of texts.
The present leader of the largest nuclear power in the world (I am writing in 2003) thinks the word is 'nucular.' He has never given any reason to suggest that his wisdom or his intelligence outperforms his literacy. He has demonstrated a predilection for 'pre-emptive' first strikes. What are the odds against a terrible mistake, initiating Armageddon?
More than 40 per cent of all mammal species are rodents, and there are said to be more individual rodents in the world than all other mammals combined.
My first book, The Selfish Gene, could equally have been called The Co-operative Gene without a word of the book itself needing to be changed... Selfishness and co-operation are two sides of the Darwinian coin.
Hippos are closer cousins to whales than hippos are to anything else including other even-toed ungulates such as pigs.
Of those 849 societies, 137 (about 16 per cent) are monogamous, four (less than one per cent) are polyandrous, and a massive 83 per cent (708) are polygynous (males can have more than one wife). The 708 polygynous societies are divided about equally into those where polygyny is permitted by the rules of the society but rare in practice, and those where it is the norm.
Overtly monogamous societies like ancient Rome and medieval Europe were really polygynous under the surface. A rich nobleman, or Lord of the Manor, may have had only one legal wife but he had a de facto harem of female slaves, or housemaids and tenants' wives and daughters. Betzig cites other evidence that the same was true of priests, even those who were notionally celibate.
It is no use saying to these people that, depending upon the human characteristic that interests you, a foetus can be 'half human' or 'a hundredth human.' 'Human,' to the qualitative, absolutist mind, is like 'diamond.' There are no halfway houses. Absolutist minds can be a menace. They cause real misery, human misery. That is what I call the tyranny of the discontinuous mind, and it leads me to develop the moral of the Salamander's Tale.
I believe race is yet another of the many cases where we don't need discontinuous categories, and where we should do without them unless an extremely strong case in their favor is made.
People and chimpanzees are certainly linked via a continuous chain of intermediates and a shared ancestor, but the intermediates are extinct: what remains is a discontinuous distribution.
Plato, whose philosophy can be seen as the inspiration for Essentialism, believed that actual things are imperfect versions of an ideal archetype of their kind.
There is no such thing as essence.
Plato might find it ironic to lean that it is actually an imperfection-- the sporadic ill-fortune of death-- that makes the separation of any one species from another possible.
In a world of perfect and complete information, fossil information as well as recent, discrete names for animals would become impossible. Instead of discrete names we would need sliding scales, just as the words hot, warm, cool and cold are better replaced by a sliding scale such as Celsius or Fahrenheit.
Evolution is now universally accepted as a fact by thinking people...
If you follow human ancestry backward to the shared ancestor and then forward to chimpanzees, the intermediates all along the way will form a gradual continuum in which every generation would have been capable of mating with its parent or child of the opposite sex.
Every speciation begins with some sort of initial separation between two populations of the same species.
The insects alone constitute at least three-quarters of all animal species, and probably more.
The residue that emerges from the rear end of an aphid is sugar-water-- 'honeydew'-- only slightly less nutritious than the plant sap that goes in at the front. Any honeydew not eaten by ants rains down from trees infested with aphids, and is plausibly thought to be the origin of 'manna' in the Book of Exodus.
"Race' is not a clearly defined word. 'Species,' as we have seen, is different. There really is an agreed way to decide whether two animals belong in the same species: can they interbreed?
All the free oxygen in the atmosphere comes from green bacteria, whether free-living or in the form of chloroplasts.
As with photosynthesis itself, bacteria still have a monopoly on the technology except that, again as with photosynthesis, eukaryotic cells like ours give house room to these oxygen-loving bacteria, who travel under the name of mitochondria.
This is the ancient 'Argument from Design,' also called the 'Argument from Paley's Watchmaker,' or the 'Argument from Irreducible Complexity.' I have less kindly called it the 'Argument from Personal Incredulity' because it always has the form: 'I personally cannot imagine a natural sequence of events whereby X could have come about. Therefore it must have come about by supernatural means.' Time and time again scientists have retorted that if you make this argument, it says less about nature than about the poverty of your imagination. The 'Argument from Personal Incredulity' would lead us to invoke the supernatural every time we see a good conjuror whose tricks we cannot fathom.
Bacteria taken as a group are the master chemists of this planet. Even the chemistry of our own cells is largely borrowed from bacterial guest workers, and it represents a fraction of what bacteria are capable of. Chemically, we are more similar to some bacteria than some bacteria are to other bacteria. At least as a chemist would see it, if you wiped out all life except bacteria, you'd still be left with the greater part of life's range.
If animals and plants are treated as a pair of kingdoms, by the same standards there are dozens of microbial 'kingdoms,' whose uniqueness entitles them to the same status as animals and plants.
Perversely, the spontaneous generation theory was supported by the Church (following Aristotle in this as in so much else). I say perversely because, at least with hindsight, spontaneous generation was a direct a challenge to divine creation as evolution would ever be.
Ultimately, design cannot explain anything because there is an inevitable regression to the problem of the origin of the designer.
The Wright brothers did not have a blinding flash of inspiration and promptly build a Concorde or a Stealth bomber. They built a creaking, rickety crate that barely lifted off the ground and lurched into a neighbouring field. From Kitty Hawk to Cape Canaveral, every step of the way was built on its predecessors. Improvement is gradual, step by step in the same continued direction, fulfilling our definition of progressive.
There are those who think Darwin's theory of evolution by natural selection explains microevolution, but is in principle impotent to explain macroevolution, which consequently needs an extra ingredient-- in extreme cases a divine extra ingredient!
My objection to supernatural beliefs is precisely that they miserably fail to do justice to the sublime grandeur of the real world. They represent a narrowing-down from reality, an impoverishment of what the real world has to offer.
CONTENTS
THE CONCEIT OF HINDSIGHT
- THE GENERAL PROLOGUE
- THE PILGRIMAGE BEGINS
- The Farmer's Tale
- The Cro-Magnon's Tale
- Rendezvous 0
- ALL HUMANKIND
- The Tasmanian's Tale
- Eve's Tale
- ARCHAIC HOMO SAPIENS
- The Neanderthal's Tale
- ERGASTS
- The Ergast's Tale
- HABILINES
- The Handyman's Tale
- APE-MEN
- Little Foot's Tale
- Epilogue to Little Foot's Tale
- Rendezvous 1
- CHIMPANZEES
- The Bonobo's Tale
- Rendezvous 2
- GORILLAS
- The Gorilla's Tale
- Rendezvous 3
- ORANG UTANS
- The Orang Utan's Tale
- Rendezvous 4
- GIBBONS
- The Gibbon's Tale
- Rendezvous 5
- OLD WORLD MONKEYS
- Rendezvous 6
- NEW WORLD MONKEYS
- The Howler Monkey's Tale
- Rendezvous 7
- TARSIERS
- Rendezvous 8
- LEMURS, BUSHBABIES AND THEIR KIN
- The Aye-Aye's Tale
- THE GREAT CRETACEOUS CATASTROPHE
- Rendezvous 9
- GOLUGOS AND TREE SHREWS
- The Colugo's Tale
- Rendezvous 10
- RODENTS AND RABBITKIND
- The Mouse's Tale
- The Beaver's Tale
- Rendezvous 11
- LAURASIATHERES
- The Hippo's Tale
- The Seal's Tale
- Rendezvous 12
- XENARTHRANS
- The Armadillo's Tale
- Rendezvous 13
- AFROTHERES
- Rendezvous 14
- MARSUPIALS
- The Marsupial Mole's Tale
- Rendezvous 15
- MONOTREMES
- The Duckbill's Tale
- What the Star-Nosed Mole Said to the Duckbilled Platypus
- MAMMAL-LIKE REPTILES
- Rendezvous 16
- SAUROPSIDS
- Prologue to the Galapagos Finch's Tale
- The Galapagos Finch's Tale
- The Peacock's Tale
- The Dodo's Tale
- The Elephant Birds Tale
- Epilogue to the Elephant Bird's Tale
- Rendezvous 17
- AMPHIBIANS
- The Salamander's Tale
- The Narrowmouth's Tale
- The Axolotl's Tale
- Rendezvous 18
- LUNGFISH
- The Lungfish's Tale
- Rendezvous 19
- COELACANTHS
- Rendezvous 20
- RAY-FINNED FISH
- The Leafy Sea Dragon's Tale
- The Pike's Tale
- The Mudskipper's Tale
- The Cichlid's Tale
- The Blind Cave Fish's Tale
- The Flounder's Tale
- Rendezvous 21
- SHARKS AND THEIR KIN
- Rendezvous 22
- LAMPREYS AND HAGFISH
- The Lamprey's Tale
- Rendezvous 23
- LANCELETS
- The Lancelet's Tale
- Rendezvous 24
- SEA SQUIRTS
- Rendezvous 25
- AMBULACRARIANS
- Rendezvous 26
- PROTOSTOMES
- The Ragworm's Tale
- The Brine Shrimp's Tale
- The Leaf Cutter's Tale
- The Grasshopper's Tale
- The Fruit Fly's Tale
- The Rotifer's Tale
- The Barnacle's Tale
- The Velvet Worm's Tale
- Epilogue to the Velvet Worm's Tale
- Rendezvous 27
- ACOELOMORPH FLATWORMS
- Rendezvous 28
- CNIDARIANS
- The Jellyfish's Tale
- The Polypifer's Tale
- Rendezvous 29
- CTENOPHORES
- Rendezvous 30
- PLACOZOANS
- Rendezvous 31
- SPONGES
- The Sponge's Tale
- Rendezvous 32
- CHOANOFLAGELLATES
- The Choanoflagellate's Tale
- Rendezvous 33
- DRIPS
- Rendezvous 34
- FUNGI
- Rendezvous 35
- AMOEBOZOANS
- Rendezvous 36
- PLANTS
- The Cauliflower's Tale
- The Redwood's Tale
- Rendezvous 37
- UNCERTAIN
- The Mixotrich's Tale
- THE GREAT HISTORIC RENDEZVOUS
- Rendezvous 38
- ARCHAEA
- Rendezvous 39
- EUBACTERIA
- The Rhizobium's Tale
- Taq's Tale
- CANTERBURY
- THE HOST'S RETURN
- Further Reading
- Notes to the Phylogenies
- Bibliography
- Illustration Credits
- Index
To purchase this book online, click below:The Ancestor's Tale : A Pilgrimage to the Dawn of Evolution
Other books by Richard Dawkins:
A Devil's Chaplain (hardcover)
Unweaving the Rainbow (hardcover)
Climbing Mount Improbable (paperback, hardcover)
River Out of Eden (paperback )
The Blind Watchmaker (paperback)
Blind Watchmaker: An Evolution Simulation (software, Macintosh only)
The Selfish Gene (paperback, hardcover)
The Extended Phenotype (paperback)
