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Why Elephants Have Big Ears: Understanding Patterns of Life on Earth

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Chris Lavers is a paleontologist who specializes in wildlife ecology. It is from this point of view that he presents some of the ideas and controversies of current evolutionary theory along with some of the excitement of recent discoveries and understandings in a popular and nontechnical manner. His readable text is aimed precisely at the educated nonspecialist, but without a hint of any dumbing down.

In the title chapter we learn that elephants pump the warm blood from the interior of their bodies to the array of tubes in their ears to dissipate excess body heat. From this consideration Lavers is led to a discussion of whether dinosaurs were warm blooded or not. The evidence he presents makes it clear to this observer that they were, but his cautious conclusion is that the case hasn't been proven quite yet. Lavers hints that the dinosaurs may have to be put in another category, perhaps somewhere between warm blooded and cold, or maybe even somewhere beyond. How about: "I'm hot-blooded, check it and see" (to reprise a rock lyric).

Lavers goes to considerable depth to demonstrate how much we can learn by combining evidence from the fossil record with what we know about the metabolism of animals and how their bodies work. Dinosaur anatomy, for example, strongly suggests a closer kinship with today's avian world than with the reptilian. Furthermore, the large size of many dinosaurs is inconsistent with cold-bloodedness. Reptiles can't get as big as a Brontosaurus because (for one thing) they would not be able to regulate their temperature. Lavers points out that all the really big animals on earth today, with the exception of the giant tortoises, Komodo dragons and some snakes--and they aren't really that big--are warm-blooded. He cites the arguments of Robert Bakker and others to conclude that T. Rex, for example, wouldn't have the metabolic power to run down prey if it were cold-blooded.

I found Lavers's discussion of the difference between non-oxygen-based metabolic reactions capable of "supercharged" bursts of short-lived energy typical of reptiles, and the sustainable aerobic reactions typical of mammals like dogs and humans very interesting. The quick bursts are those of the sprinter who is wasted after at most a few hundred yards, while the aerobic engine sustains the pace of the long distance runner. Also interesting is the material in the chapter "Life on the Edge" about how birds and mammals maintain their body temperatures in the climate extremes of the deserts and the polar regions of the earth. Lavers notes that in very cold places there are no reptiles.

In some of this I am reminded of the famous and splendid essay by J. B. S. Haldane, "On Being the Right Size," published many decades ago. Lavers presents the same kind of reasoned argument based on physiology and anatomy to demonstrate why animals are built the way they are and why it would be difficult for them to be constructed otherwise. One comes away from the reading with a sense of having learned something important and exciting, a sense of having acquired understanding, not merely a collection of facts.

answers many evolutionary questions and brings up topics you probably hadn't even thought to ask about. incorporates a lot of paleontological evidence and focuses on the evolution of different groups of animals, as well as on specific species. repeatedly refers back to basic laws of physics to explain various adaptations.

readable in general, although sometimes the text is a little awkward and overly detailed and the footnotes could have been better integrated.

here's a complete rundown of the topics covered:
Ch.1: covers issues with the scaling of areas to volumes, how it affects an animal's leg shape, body size, head size, hair, etc.
Ch.2: the energy costs for cold vs. warm-blood, looks more closely at issues w/ body size
Ch.3: looks at theories about the evolution of warm-bloods
Ch.4: looks at theories about whether or not dinosaurs were cold or warm-blooded
Ch.5: adaptations for animals, including in the tundra and desert
Ch.6: why there are hardly any huge cold-bloods, except in unstable, infertile areas like Australia
Ch.7: why there are hardly any large mammals in freshwater regions, although they exist on land and in the ocean. looks at the success of crocodiles.
Ch.8: why there are many species of birds in general and why there aren't many species of large birds
Ch.9: the catastrophic events that happened when there was global warming and decrease of global biodiversity in a previous era

This book is an extended essay on the continuity of evolutionary trends. In it, Lavers examines the extremes of the animal world, the very large, the very small, animals that can withstand very hot climes or very cold ones, mammals that fly and birds that run. For each of these beasts, Lavers argues that their shape and special characteristics must have been the result of adaptation to their environment or ecological niche. He investigates not only why elephants have big ears (to cool down their enormous rotund bodies in hot climates), but also why we don't have elephant-sized lizards or birds (at least these days). Throughout the book, Lavers draws on results of research in paleontology. For example, he explains the two sides of the debate about whether dinosaurs were warm blooded, and what the implications would be for giant cold-blooded lizards. I, for one, never really cultivated an interest in dinosaurs before. But after reading this book, it's much more clear to me that the animals we see around us today are just one chapter in the overall life of the planet. The book is written in an informal style, without footnotes, but key sources are identified in endnotes at the back of the book, along with a bibliography containing hundreds of references.

Elephants can weigh up to 8 tons; their front teeth can be up to 3 meters in length and can weigh over 200 kg. And the African elephant has the largest earflaps of any animal in history. Lavers explains not only why their huge ears are the key to their curious shape but also to why rats are furry and why King Kong could never have climbed the Empire State Building. The elephant's ears, in case you are wondering, act as radiators, an important consideration if you are a lumbering giant baking under the tropical sun.
There is, Lavers's excellent book explains, method to every apparent anomaly in nature. Gazelles, for example, must be built not only to sprint but to dodge and weave as well. This is because cheetahs, which are renowned sprinters themselves, regard them as little more than mobile larders.
Dogs and wolves, on the other hand, are not great sprinters. Instead, they have great stamina and will wear down their prey by sheer perseversence and, well, doggedness. Lavers also explains such interesting things as why swans glide across the water, whereas vultures hop and ostriches cannot fly at all. He also shows how all of these different attributes go to give us the diversity of life on which we all ultimately depend.
This well written book book also explains why the furs of baby harp seals, mink, lynx, snowshoe hares and Arctic foxes are so much in demand but the pelt of a polar bear is not. Lavers also explains how the cubs of polar bears survive the harsh Arctic winter. Although polar cubs are tiny, blind and wet creatures, lacking in fur, fat and the ability to shiver, yet nature has provided the means for them to survive and become the world's biggest bear in some of the world's most inhospitable terrain. That is but one of Mother Nature's daily miracles that Lavers' book unlocks.
The Arizona based spadefoot toad provides another. It spends most of its life encased in cooling mud, emerging only when it rains to have unbridled sexual orgies, massive food binges, and to lay hosts of eggs. Once satiated and once it has ensured the regeneration of its species, it resubmerges itself in the desert's cooling mud.
The Saharan scimitar-horned oryx is a large antelope around two meters in length, which lives beneath the blazing Sahara sun. It never seeks shelter, it drinks very little water and yet it thrives by the judicious use of deep night time breathing, which generates sufficient moisture for it to live on. When the Indonesian based komodo dragon slashes its prey, its filthy fangs cause all kinds of infections, which eventually wear down the unfortunate deer or human it has ambushed. The dragon then saunters after its weakened prey and dines at its leisure.
Although hippos occasionally decapitate them by rolling them around in their mouths, crocodiles have been the undisputed king of the tropical world's freshwater systems for the last 65 million years. Because they are so perfectly adapted to their environment, the only enemy they must really fear is man, the great destroyer. Because we have introduced such ecological vandals as goats, rabbits, cats, rats and mice to fragile ecological systems like Australia and New Zealand, we have done more damage to the environment than anything else since the dinosaurs became extinct.
As well as being replete with fascinating examples such as these, Lavers' book is particularly recommended because its judicious combination of examples such as with an eminently readable style, shows how our own existence is ultimately entwined with the complex life styles of all of those other vreatures, both great and small.

Before reading this fabulous book I had no idea that scientists had missed so many important ideas in the field of natural history. Why Elephants Have Big Ears offers a whole new view of life on earth. Endlessly fascinating and beautifully written, this work is destined to become a classic.

Dear all. Greetings from England. Here are a few reviews of my book. If you buy a copy, I hope you enjoy it.

"If you want to understand evolution, read this. A pachyderm of a book!" David Bellamy

"A book which evokes a deeper fascination for nature's marvels" Richard Leakey

"Perhaps no other book available explains evolution, natural selection, and the riddles of natural history as well as Chris Lavers's Why Elephants Have Big Ears" Steve Brusatte

"Fascinating and illuminating" New Scientist

"The title of this charming books says it all. Why Elephants have Big Ears expresses a wonderfully quirky curiosity about biology. Chris Lavers skillfully melds physiology, evolution, biomechanics, and ecology to answer questions almost too big to be asked" Pat Shipman, Rhone-Poulenc Prize-winning author of The Wisdom of Bones

"Reading through this book, I was constantly marvelling at the discoveries I made...Some of the natural processes outlined are fairly complex, but Lavers writes in such an accessible way that a non-scientist like me grasped them" Paula Francis

"A fine read" Colin Tudge

Why Elephants Have Big Ears covers the basics of understanding life on earth, tackling the more obvious questions such as why elephants have evolved big ears and why there are so many birds. The answers to these and other questions take the form of explaining broad patterns of evolution in the animal world.

When I needed to book to get to grips with food and endothermy, this is the best one I could find. Written in the same genre as "Why big fierce animals are rare" (better - please no sentimentality in such material) though in the footsteps of Robert Bakker and possibly Gould or Gribbin or other popular writers, this book is very informative though it could have been more critical and less informal.

It is actually a somewhat original account summarising the latest news from the Mesozoic dwelling on dinosaurs, size, energetics, evolution and the author's fear of the amalgamation of biodiversity.

The illustrations highlight characters from the history of vertebrate evolution and the book is a send off for elephants, flightless birds, some extinct and extant reptiles.

I wish the last chapeter could have been curtailed with a more general overview of our impact on the biosphere and that the author could sound less philanthropic in his intentions.

I think the work will be much cited (I will anyway) and though he leans to warm blooded dinosaurs this could be a mistake. Excellent as a macrotaxonomic survey in the vertebrates on physiologic lines, more, much more needs to be said e.g., on secondary palates, body shape, insulation, food sources, plants, past climates. This book will need sequels.

A cardinal work.