Extremes fascinate us: the biggest, the fastest, the oldest, the tallest. Books and TV-programmes regularly scratch our itch for records, whether it is feats of engineering or biological extremes, and many sporting events revolve around humans attempting to set new records. One glance at the cover of Matthew D. LaPlante’s book Superlative and you might think that this is yet another book offering lots of gee-whiz factoids. You would also be wrong. Instead, this is an amusing and fascinating book that digs just that much deeper into the biology behind extremes, and why studying them is so worthwhile.

Superlative: The Biology of Extremes, written by Matthew D LaPlante, published by BenBella Books in May 2019 (hardback, 304 pages)

Superlative starts with an interesting observation: science often purposefully ignores statistical outliers. And yet, studying them can be revealing, showing how evolution manages to push organisms to extremes. Next to satisfying our curiosity, understanding how such extremes can exist could lead to all sorts of applications. Take size, most recently also discussed in Nature’s Giants. From books such as Scale and Why Size Matters, I already knew that most things do not scale linearly with one another. But given the vastly larger number of cells that make up an elephant, how is it they do not develop cancer more? As mammals, humans and elephants share a large amount of genetic material, but clearly the latter are doing something different. Through a close reading of both primary literature and popular articles, LaPlante explains how elephant cells activate apoptosis pathways (basically a form of cellular suicide) at the first sign of mutation.

Throughout Superlative, LaPlante employs this strategy, thus examining the world’s biggest, smallest, oldest, fastest, toughest, deadliest, smartest, and most-keen eared organisms. Bringing his background as a newspaper reporter to bear on this topic, he offers plenty of interesting tidbits with the wide-eyed wonderment of an outsider while witty footnotes provide more details on some of the interesting research that he puts in the spotlight here. There was plenty here that raised my eyebrows, though, as mentioned, the book avoids being a mere collection of factoids, rather seeking to stimulate deeper reflection.

“Even for simple metrics such as speed or age, determining who is the faster or oldest is less straightforward than you might think.”

For one, it is not always easy to determine who is the most extreme in something. When it comes to something as complex as intelligence this should come as no surprise. LaPlante discusses dolphins (admittedly a somewhat loaded topic) to then show how other animals are also very smart, including octopuses, elephants, ants, plants, and even slime moulds. Each of these is smart in their own unique way.

But even for simpler metrics such as speed or age, determining who is the most extreme is less straightforward than you might think. Sure, cheetahs are fast, but not for very long. And when you measure speed in comparison to body size, they pale in comparison to tiny mites which have been shown to sprint over 300 body lengths per second. Slow in absolute terms, but lighting-fast in relative terms. Age can be similarly slippery. A bristlecone pine nicknamed Methuselah is estimated to be 4,850 years old, but what of clones? Aspen trees exist as clonal colonies that might well be tens to hundreds of thousands of years old, taking the cake for being both the oldest and largest organisms on the planet – though certain fungal colonies might disagree (the wonderful coffee-table book The Oldest Living Things in the World illustrates many of the plants LaPlante mentions).

“Many record-holders are threatened with extinction, and many others might disappear before we had a chance to learn much about them, or to even become aware of their existence in the first place!”

The other thing is that many of the current record holders may not stay that way for long, for we often simply have not looked very hard. New discoveries can be made under our very noses, such as the world’s smallest frog (average length: a mere 7.7 mm), which was found in between leaf litter layers where nobody had thought to look. Admittedly, in some cases, we need to look outside of our normal range of perception, such as with infra- and ultrasound. But the real reason LaPlante flags this up is his concern with the biodiversity crisis. Many record-holders are threatened with extinction, and many others might disappear before we had a chance to learn much about them, or to even become aware of their existence in the first place!

The last way in which his theme of extremes serves a larger purpose is that LaPlante uses it to make a case for fundamental research. Much of the science discussed here superficially seems quirky and pointless (Do elephants experience long-term trauma? Why are waterbears so tough? How do these super fast tiny mites change direction?). But seeing scientific knowledge only through the lens of immediate (monetary) applications is a shallow perspective. In that sense, Superlative does a, well, superlative job of pointing out the value of seemingly useless research. Whether it is better understanding morphology, physiology, diseases, ageing, or evolution, we can learn an awful lot about both our own and other’s biology by being more observant of nature’s extremes. To that end, Superlative offers a very pleasant mix of mindblowing facts and a deeper context into which to place them.

Disclosure: The publisher provided a review copy of this book. The opinion expressed here is my own, however.

Superlative paperback, hardback, ebook, audiobook or MP3 CD

Other recommended books mentioned in this review:

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“Sloths! A Celebration of the World’s Most Maligned Mammal“, written by William Hartston, published by Atlantic Books in October 2018 (hardback, 198 pages)

Author William Hartston, a mathematician and psychologist, has written a string of chess and trivia books and so might not seem like the logical choice to write a book about sloths. But, as he shows admirably here, as long you are fascinated with a topic and willing to dive into it and talk to experts, that matters little. Just add a little water, no biologist required.

Sloths! is a slim but entertaining introduction to sloths. If you have ever read one of the many books in the Animal series from Reaktion Books, you know what to expect: an accessible mixture of history, biology, and culture. Coincidentally, there is no volume on sloths in this series, and, well, it looks like they have missed the boat now.

Hartston has talked to various sloth researchers and here surveys recent scientific literature. In fifteen short chapters, he walks the reader through the sloth’s evolutionary history, the five currently extant species, their basic biology, anatomy, diet, and conservation. Obviously, a book of this calibre answers such questions as “Does it fart?” (not really, it burps more than it farts), “Does it poop?” (yes, but not as often as you might think), or “How do they have sex?” (other than slowly, we do not really know, it has barely been observed).

“Some of the big names in natural history, such as Cuvier and Comte de Buffon, described the sloth as a wretched, dismal creature based on second-hand information.”

Just because I bring up these trivia-favourites, do not think this book is all puerile. Hartston’s excursion into the history of the sloth’s entrance into the European scientific literature is very interesting. It is remarkable how some of the big names in natural history such as Cuvier and Comte de Buffon, based on second-hand information, described the sloth as a wretched, dismal creature. It is true, being part of the superorder Xenarthra, they have unusual joints. When encountered at ground level, rather than hanging upside down from a branch, they are like a fish out of water. They can indeed not walk but have to drag themselves around. But that does not mean they are not supremely adapted to their habitat.

It was not until the London Zoo was gifted a sloth from the Dublin Zoo that the sloth was rehabilitated in the English literature. More recently, it is thanks to the Sloth Sanctuary in Costa Rica and researchers such as Lucy Cooke and Lucy Houliston who founded the Sloth Appreciation Society that the sloth has exploded into popular consciousness. Although raising the sloth’s profile, this comes at a price. The Sloth Sanctuary has been criticised by former employees (see this article on The Dodo), and the animal’s popularity has led to other shelters popping up that capture wild sloths so that tourists can take cute pictures with them. Needless to say, you are best off trying to observe animals in the wild only. Any such local tourist trap, whether it concerns sloths or other animals, is highly likely best avoided, unless you have done your background research. But I digress.

There are surprisingly few books published on sloths. Besides some children’s books, there have recently only been a few photographic books – Cooke’s Life in the Sloth Lane: Slow Down and Smell the Hibiscus (more of a mindfulness book) and Rebecca Cliffe’s Sloths: Life in the Slow Lane – which are thin on written content. At the other end, you are looking at some academic tomes that are quite old: Goffart’s Function and Form in the Sloth was published in 1971. More general, but very expensive, is Vizcaino & Loughry’s 2008 book The Biology of the Xenarthra. After that you would already have to turn to general wildlife encyclopedias such as the recent Walker’s Mammals of the World: Monotremes, Marsupials, Afrotherians, Xenarthrans, and Sundatherians or Handbook of the Mammals of the World, Volume 8: Insectivores, Sloths and Colugos.

This book, then, fills a sloth-sized gap in the market. Entertaining, informative, very reasonably priced, and perfectly giftable.

Disclosure: The publisher provided a review copy of this book. The opinion expressed here is my own, however.

Hartston’s Sloths! hardback or ebook

Other recommended books mentioned in this review:

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