Thursday, July 23, 2015

Walking Whales: The journey from land to water in eight million years by Hans Thewissen - Book Review


How Whales originated in India and conquered the Oceans!

Evolution provides countless of amazing stories as we look at how each species evolved.  But story of the whales  (which are mammals) ancestors that went from land to water about 40 to 50 million years ago beats the best of them. And in between for a few million years there were whales (much smaller off course than the ones we see now) that had legs and could walk on land as well as swim in the water!

Hans Thewissen who discovered the first ‘walking whale’ later called Ambulocetus in Pakistan in the early 1990s, tells this fantastic story in great detail. The science behind the discovery and the subsequent journey is meticulously explained and this book will be a great learning experience for any reader. Starting from what makes a whale a whale (it is the tymphanic bone in the ear), to the importance of teeth and the dental formula (just by a tooth an expert can tell you what species it belongs to!) is amazing. Other interesting facts such as the oxygen isotopes in the bones that lets you determine whether the species lived in land or water, makes the book so enjoyable to read.

Perseverance is the key to success and the author’s efforts in India and Pakistan over the last 20 years in searching for and discovering numerous fossils and his focused studies in understand the swimming, feeding, breeding activities of this species underlies that.  The deciphering of  the development of the brain, vision, hearing etc of the Ambulocetus and related species from different fossil fragments makes a large part of the book feels like a detective story. The author’s skill in explaining not only biology and paleontology, but also other domains like geology and plate tectonics is wonderful. I have not read a better explanation of plate tectonics anywhere else! The isolation of the Indian peninsula after it broke away from the Africa about 50 million years ago gave the walking whales an opportunity to evolve in isolation.

Many Indians spent considerable time worshipping their Gods in the Himalayas but instead if they had spent a fraction of that time understanding how the Himalayas were formed, they might be able to appreciate the forces of Nature better. And the story of the Whales and their journey to conquer the oceans should be inspiring to all Indians.