Superlative The Biology of Extremes

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 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.

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, see my review of Are Dolphins Really Smart?) to then show how other animals are also very smart, including octopuses (see The Soul of an Octopus and Other Minds), elephants, ants, plants (see also my review of The Revolutionary Genius of 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).

he 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 (see also Calls Beyond Our Hearing). 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 as also argued in Science Unshackled and my review of The Usefulness of Useless Knowledge, 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.