Book Review: Otherlands
By Thomas Halliday
Thomas Halliday’s Otherlands provides a sampling of 16 environments that have existed at various points during the Earth’s 4.6-billion-year history. Halliday is a paleontologist and evolutionary biologist at the University of Birmingham specializing in the evolution of mammals and phylogenetics. The breadth displayed in Otherlands extends far beyond the origin and rise of the mammals, however, with Halliday displaying an apt hand at sketching the contours of long-lost lands and the flora and fauna that inhabited them.
The book is arranged as a walk backward through time, starting in the near past—20,000 years ago on the Pleistocene tundra of Alaska—and ending with the first appearance of multicellular life roughly 550 million years ago (MYA) during the Ediacaran in what would one day be Australia. The arrow of time, of course, moves forward, and most authors who tend to this subject go with the flow. Halliday, on the other hand, deliberately puts his time machine into reverse, choosing to start the book with long-ago worlds that are, nonetheless, somewhat familiar to us. The tundra of 20,000 years ago is populated by Halliday with horses, bears and mammoths, all well known to most readers—even if the horses’ legs are shorter and the short-faced bear is four-times heavier than a modern grizzly.
The problem—and an obvious one—with this approach is that evolution more or less follows time’s arrow. Whether emerging for the first time at, as current thought supposes, a hydrothermal vent on the seafloor or re-emerging after one of the five major extinction events, life not only radiates outward into the vacuum it abhors but also, as a general rule, complicates, new species diverging from ancestral species. This is by no means to say that every new species is more complex than the one from which it evolved. A mutation that causes a plant or animal to be better adapted to its environment and thus better able to perpetuate its genes does not, perforce, mean that the new species that may originate from this genetic line is more genetically or biologically complex than the species from which it differentiated. However, taken as a whole, life has, over time, built from single cells to astounding multicellular entities that can swim, run, fly and even turn sunlight into sustenance (I am admittedly in awe of photosynthesis; if only I could make chocolate from sunshine!). Benthic creatures that lived and fed passively anchored to the ocean floor were eventually joined by pelagic creatures that swam and ate other things that swam, all made possible by the development of a notochord and endochondral bone and fins and mouths with teeth. And those early fish, over millions and millions of years, gave rise to tetrapods—amphibians, reptiles, dinosaurs, birds and mammals. Moving backward through the history of life, a reader who lands in the Triassic of Chapter 9 but does not know about the disastrous extinction that ended the Permian does not have the context to appreciate the marvel that any tree, that any animal, that any life at all is present in this world for Halliday to write about. Perhaps relying on the context of the present day to ground the journey backward is a wiser authorial strategy for the current era with its unwillingness or, worse, inability to logically tie cause to effect than providing fussy old nitpickers like me with the context of the past on which to build the future.
Regardless of how he orders them, Halliday conjures the worlds he guides us to like a magician, pulling a Mesodoma from the ferny forests of Hell Creek, Montana in his chapter on the Paleocene or giving us a glimpse of Omnidens amplus, the Cambrian’s version of the Jabberwocky. Rather than try to depict an entire world in a chapter, Halliday narrows his focus to a particular time and place and spends the bulk of each chapter exploring that singular ecosystem with allusions throughout to the biology, geology and chemistry that define the time and surround the chosen spot. The rock where I live was laid down in the temperate seas of the Ordovician, and I was at first disappointed by his decision to explore this period in the glacial seas off the coast of Soom, South Africa. I wanted to read about the brachiopods and cephalopods and gastropods I pull from nearby roadcuts, but Halliday took me to a much less familiar world of a polynya, and I ended the chapter grateful for this excursion into an exotic space whose existence I had never considered. Halliday has selected the best of the best-preserved fossil sites as the grounds for his otherlands, and this allows him to explore a wide variety of terrestrial and marine ecologies solidly grounded in the work of the scientists who discovered, cataloged and worked to understand these doorways into the past. Spending the Devonian in the landlocked mountains of Scotland was an interesting choice—I mean, come on, the Devonian is the Age of Fishes!—but making the acquaintance of Palaeocharinus rhyniensis, an ancient whip spider, as it pierced, crushed and digested its prey outside of its body was, if not a pleasure, definitely interesting.
One final quibble with the book is the dearth of illustrations. A drawing of the earth of that period with the site highlighted appears at the first of each chapter, and the third page contains a line drawing of a single specimen that will make an appearance. But the worlds Halliday paints are lush with animals, plants and ancient vistas, and I would dearly love to see them in their full glory. So, Dr. Halliday, there’s a next book for you: partner with an artist (if you yourself are not one) and show us these otherlnads that you have here told us about. You would sell at least one copy.
Learn more about Thomas Halliday and his work at www.thomashalliday.co.uk/.