Richard Dawkins’ 2004 popular science book, The Ancestor’s Tale, is loosely

modelled on Chaucer’s Canterbury Tales. Instead of pilgrims journeying to

Canterbury, Dawkin’s protagonists are living species, journeying back through

evolutionary time.

In real time, individual species diverged and speciated. But in the

backwards time of The Ancestor’s Tale, separate species start the

journey apart, in the present, and “converge” together as they

descend into the past. Humans “meet” the chimpanzee and the

bonobo around 6 million years ago. We all continue back in time

together, rendezvousing with gorillas another million years earlier.

The time doubles before the next

convergence, with orang utans, at 14 million years ago. Dawkins takes

his readers back and back and back. We eventually meet rodents and

rabbits at 75 million years, amphibians at 340 million years, lungfish

at 417 million years.

Insects, spiders, worms, snails and other protostomes are all more

closely related to one another than to us, so on their own journey they

have already converged. We meet them as one huge scuttling,

crawling, sliding band at around 590 million years ago. The common

ancestor – the “concestor” in backwards time – which we share with

the protostomes, was probably worm-like, segmented, with a mouth

at the front, and probably had eyes.

Dawkins reversal of time is designed to exorcise the “conceit of hindsight”,

in which all of evolution is seen as something inevitably progressing

towards the human and in which we lazily describe one species as

“more evolved” than another, for example. The Ancestor’s Tale is a

fascinating overview of all life on earth. Our small hope is that the

Ancestor’s Trail will help to illustrate the tree of life by symbolically

walking the journey back

to the origin of life.