One of the images that says "evolution" more than any other to the average person is the much-spoofed drawing of a sequence of species running from fish to humans. This image bothers many scientists because it embraces a long-discredited notion that evolution is directed forward towards something (namely, us), when it is, in fact, purely driven by contingency -- what happens in evolution is completely dependent on the past and the present, with no looking forward.
In The Ancestor's Tale, Dawkins reverses things and runs the sequence back from us through the 40 major branchings that have happened in our family tree, towards the common ancestor to all modern life -- sort of like the recent Guiness commercial that made it's rounds on the Web (though the ad has some major mistakes in the species used). Since one can look back without suggesting predestination, this makes for a less misleading perspective on evolution.
As you might have guessed from the title's form and its reference to a pilgramage, The Ancestor's Tale's structure is based loosely on Chaucer's Cantebury Tales. Dawkins tells the tales of the modern descendants from each of the 40 branch nodes in our evolutionary history (for some nodes, he tells tales for many different descendants), just as the pilgrims in Chaucer's stories told their own.
For those who are curious, the 40 cousins of ours (actually, 39 cousins plus ourselves) whose tales are told are:
- Orang Utans
- Old World Monkeys
- New World Monkeys
- Lemurs & Bushbabies
- Colugos & Tree Shrews
- Rodents & Rabbits
- Laurasiatheres (hippos, seals, etc)
- Xenarthrans (armadillos, etc)
- Sauropsids (ancestors to birds)
- Ray-finned Fish
- Lampreys & Hagfish
- Sea Squirts
- Acoelomorph Flatworms
- Cnidarians (jellyfish)
This list is just from the table of contents, so I don't yet know what "DRIPs" are (other than that they're on page 507) or why #37 is "Uncertain". Those details will have to wait until the next post.