Sunday, July 19, 2009

Grilled Fish

This appeared in today's DNA.


At a time when some people are still getting over the fact that men and monkeys swing from the same family tree comes this work by Neil Shubin, asserting that many characteristics we think of as distinctively human are actually shared by fish, among other creatures. Clearly, Your Inner Fish is not to be read while dining at Mahesh Lunch Home.

It was the unearthing of a 350 million-year-old fossilized fish, an intermediate between land and water organisms, that’s the starting point of this book. For Shubin, paleontologist and evolutionary biologist at the University of Chicago, such ancient fish bones are more valuable than gold, which is why he spent years with his team turning over rocks in the snowy wastes of the Canadian Arctic, braving polar bears and ice storms. The abovementioned sea creature, dubbed Tiktaalik after an Inuit term for freshwater fish, had flippers to enable it to move on land and from a study of its skeleton, Shubin finds fascinating Darwinian connections with the way human beings themselves have evolved.

Be it a frog, bat, lizard or human, the deep similarities between bodies shows that they’re all variations on a theme, he writes. “Most of the major bones that humans use to walk, throw or grasp appeared in animals ten to millions of hundreds of years before.” The development of teeth, for example, initially used to bite, led to structures designed to protect - and the same developmental forces led to the creation of feathers, mammary glands and hair. In another instance, a segmented skeletal structure leads him to point out developmental similarities between the head of a shark and that of a human being (all human beings, not just real estate developers).

Shubin also illustrates how the shared genetic code of all living organisms reinforces his variations-on-a-theme thesis. We may not look much like sea anemones and jellyfish, but the recipe that builds us is a more intricate version of the one that builds them. Along the way, he points out the links between a mammalian ear and a shark's jaw, as well as the varying roles and development of visual and olfactory organs. Should you be so inclined, he even tells you how to extract DNA in your kitchen, using the simplest of equipment.

Shubin is clearly passionate about his subject, enthusiastic about communicating his theories, and possesses the ability to clarify abstruse concepts. All of which makes Your Inner Fish illuminating and interesting, aided by the occasional personal anecdote, from haggling with antique fossil dealers in China to visits with his son to New York’s Museum of Natural History. It ought to be said, however, that on occasion the level of simplification appears to be too much: perhaps this springs from the desire to communicate to as broad a readership as possible.

The point of it all, which is what Shubin sums up with, is that there’s a universal biological law: every living thing on the planet has parents - more specifically, parental genetic information – and therefore, all of us are modified descendants of those that came before. This, among other things, throws light on how our evolutionary past causes problems when it comes to our current lifestyle, from hiccups to hernias (the former, by the way, is derived from gill breathing in tadpoles).

The British biologist J.B.S. Haldane, who pointed out the evolutionary significance of Vishnu’s avatars from fish onwards, once said, “The universe is not only queerer than we suppose, but queerer than we can suppose”. In identifying the links that bind us all together, Neil Shubin goes some way in making the living universe less mysterious.

No comments: