Having recently finished reading Richard Dawkins’ The Ancestor’s Tale (and already posting about it here and here) I feel inclined to offer a brief book review, and then delve into one of the most fascinating recurring themes in the book.
The Ancestor’s Tale tells the history of life. That’s pretty broad. So the questions are how to pick a starting point and what to focus on? The format of the book is unique, beginning with homo sapiens (an understandable bias) and working its way backward in chronological time. This structure constantly reinforces the concept that evolution is not “intentional” or “progressive” in certain specific senses; if the clock was wound back and history was played out with even the slightest variations, any specific species (including humans) probably wouldn’t have evolved, or would be very different. So, viewing evolutionary history frontwards always carries the risk of seeing species evolving “toward” the present, and evolution simply is not directional in that sense. Dawkins calls this misperception “the conceit of hindsight”: We evolved, therefore we were meant to evolve. Not so.
The narrative structure of the book is therefore intentionally counterintuitive, and it’s something that Dawkins handles well. The reader is constantly reminded of this special caveat for evolutionay thinking, as intended by the author. That said, Dawkins also adds narrative wit by paralleling the Ancestor’s Tale to Chaucer’s Canterbury Tales, albeit loosely. Going back in time the narrative slowly picks up more characters. Beginning with humans, then picking up modern species that represent groups that diverged from ‘our line’ at some point in the past; chimpanzees, gorillas, the other apes, Old World monkeys, New World monkeys, more primates, rodents, laurasiatheres, xenarthrans, marsupials, monotremes, sauropsids, amphibians, and so on, back to the dawn of time.
Dawkins also does a good job of discussing various evidences for differing viewpoints and current controversies, clearly demarcating that which is widely agreed upon (chimpanzees are our closest modern relative), often instances in the (evolutionarily) recent past to the uncertain (the order of the rooting of the tree for mixotrichs, archae, and eubacteria), often more distant in evolutionary time.
That said, I liked the book. A recurring point that stood out to me was “the tyranny of the discontinuous mind.” Dawkins often referred to cases where our need to categorize, group, and name things which may in reality fall in a continuum, not discrete categories, gets in the way of the most accurate descriptions.
Names are a menace in evolutionary history. It is no secret that paleontology is a controversial subject in which there are even some personal enmities. At least eight books called Bones of Contention are in print. And if you look at what two paleontologists are quarreling about, as often as not it turns out to be a name. Is this fossil Homo erectus, or is it an archaic Homo sapiens? Is this one an early Homo habilis or a late Australopithecus? People evidently feel strongly about such questions, but they often turn out to be splitting hairs. Indeed, they resemble theological questions, which I suppose gives a clue to why they arouse such passionate disagreements. The obsession with discrete names is an example of what I call the tyranny of the discontinuous mind….
He then offers some excellent examples, which I shall write about soon.