Written by Vikram Aditya
“Life on Earth: A fresh outlook to our common origins”
Richard Dawkins needs no introduction to most students of science. An evolutionary biologist, ethologist and Emeritus Fellow at Oxford University, his books on the evolution of the natural world have inspired a generation of youth to study biology and take an active interest in science. His lucid and straightforward approach to explaining the fascinating living wonders of our planet have endeared him to many. Some of his books, most notably The Selfish Gene, have radically changed popular perspectives of how evolution works by presenting a gene-centered view of evolution. But his unyielding defense of Darwinian evolution has also made him the target of the conservative right.
His book The Ancestor’s Tale: A Pilgrimage to the Dawn of Life, first published in 2004, offers a unique way of looking at life on our planet. In it, Dawkins invites us on a pilgrimage back through time to meet our ancestors. We trace our steps back through human evolution, encountering 40 rendezvous points where we are joined initially by other species from whom the human lineage split off, and subsequently through whole groups of species with whom we share a common progenitor and therefore have a shared descent. This narrative device employed by Dawkins is quite unprecedented in popular science writing on evolution and biology. His reminder that we are all connected through a common origin, which we share with bacteria and slime mould, is worth re-emphasizing in the current global extinction crisis, especially to those who place humans on a pedestal distinct from other “animals”.
In The Ancestor’s Tale, our first rendezvous is with the chimpanzees and the bonobos. We shared a common ancestor with them around 6 million years ago and therefore around 99% of our genome is the same as theirs, meaning that any random sequence of human and chimp DNA is almost identical except for one to two differences on average. Another million years back in time, and the three of us meet up with the two living species of gorillas, and then with the orangutan. As we continue retracing our steps, species that have already become extinct join us as “shadow pilgrims”. Eventually, all living species on Earth along with the extinct “shadows” walk together on the final stretch to meet the last universal common ancestor (popularly known as LUCA), from which all life on Earth descended around 4 billion years ago.
At various points, some species which join us along with their taxonomic groups recount their interesting tales which offer insights into some of the mechanisms by which evolution works: for instance, the Peacock’s Tale is about the role of sexual selection in the appearance of the peacock’s tail, the Marsupial Mole’s Tale illustrates convergent evolution, the Polypifer’s Tale explains cooperation within ecological communities like coral reefs.
Some readers might be daunted at the size of the book – 626 pages – and might find the second half somewhat protracted. But the language is uncomplicated and straightforward, and the illustrations are beautiful. This fascinating book made me truly appreciate the interconnectedness of life on Earth, like no other book on evolution that I had read before. I am sure you will not be disappointed either!
About the Author:
Vikram Aditya joined the ATREE PhD programme in 2011. His PhD research is on studying the patterns of landscape change over the past three decades in the Papikonda National Park, in the Eastern Ghats of Andhra Pradesh, India and its effects on mammalian diversity and distribution patterns in the region. He has an M.Sc in Zoology. He has worked previously with WWF India from 2006 to 2010 and as a National Geographic Young Explorer Grantee in 2010.