Ever since humans appeared on the scene, we have been altering life on Earth. Where once our actions could be considered part of nature’s fabric, our influence has become outsized and our options to exercise it have multiplied. Though the subtitle of Life Changing does not make it explicit, science writer Helen Pilcher focuses on our impact on the genetics and evolution of life around us. A book that stands out for its balanced tone, it managed to surprise me more than once, despite my familiarity with the topics considered.
Life Changing: How Humans Are Altering Life on Earth, written by Helen Pilcher, published by Bloomsbury Publishing in February 2020 (hardback, 391 pages)
Life Changing is told in three acts. Pilcher first examines the species we have purposefully engineered, then looks at the many animals unwittingly caught up in the advancing human juggernaut, and finally considers how we might wield our knowledge for good in conservation efforts. Examining the work of numerous scientists, she takes the reader through topics as diverse as domestication, cloning, invasive species, urban evolution, de-extinction, and rewilding. Two aspects of her writing stood out for me in particular: she gets the nuances of these technical topics right, and she is balanced, not letting personal prejudice get in the way.
First, those nuances. As a former reporter for Nature and with a PhD in cell biology, Pilcher understands the biology and knows how to communicate it. Right off the bat, she clarifies that domestication is simply another form of genetic modification. Making a distinction between this and modern, laboratory-based methods, as GMO opponents are often wont to do, is a good example of the appeal to nature fallacy. The difference is one of degree, not of kind. She similarly puts the record straight on cloning: clones are not 100% genetically identical. Although you duplicate the nuclear DNA, you will need an egg cell in which to do so. The egg donor contributes its own mitochondrial DNA, which is a small but not insignificant fraction. With time, further differences accrue due to mutations and epigenetics (processes that change the way DNA is expressed without changing the DNA sequence). “We are all far more than the sum total of our DNA” (p. 136), remarks Pilcher. The last example is de-extinction, the subject of one of her previous books. Often misrepresented as resurrecting an extinct species, in reality it means genetically modifying a closely related species to resemble its ancestor. The result is “a hybrid modern-day facsimile” that “doesn’t mark a return to bygone eras; instead it marks an entirely new phase in the evolutionary story” (p. 138).
The second strong suite of Life Changing is Pilcher’s balanced reporting. Cloning has found many uses in animal breeding, but we must not forget that it is a notoriously inefficient process with most clones dying before birth—which is one reason why she would not want to clone her dog. When discussing the genetic changes wrought by trophy hunting, she admits finding the whole business repugnant but recognises how South Africa has shown that the money ploughed back into wildlife reserves benefits wildlife overall. “Although it may seem counter-intuitive, sometimes, hunting can actually help wildlife” (p. 63). And while invasive species have a bad reputation, she also speaks at some length to ecologist Chris D. Thomas. In his book Inheritors of the Earth, he pointed out how many invasive species simply slot right into an ecosystem without disturbing the locals. New Zealand now has nearly double the number of plant species. “Despite what you might have heard, invasive species aren’t all bad” (p. 229).
“[…] de-extinction [is] often misrepresented as resurrecting an extinct species, in reality it means genetically modifying a closely related species to resemble its ancestor.”
Particularly interesting is the topic of hybridisation. There is much concern about closely related species hybridising as climate change causes home ranges to shift, with pizzlies (polar–grizzly bear hybrids) being one example. But, just as humans contain some Neanderthal DNA, studies have shown grizzly bears to contain some polar bear DNA; one example of the book surprising me with something I did not know yet. It is estimated that the two species have occasionally interbred for the last 40,000 years. So should we panic? This is perhaps where Pilcher’s logic lapses slightly. When she introduces extinction and climate change she admits that, yes, these are natural processes that have always happened, but it is the current high rate that is worrisome. That same logic is not applied to her discussion of hybridisation. On the flip side, it can also be a conservation tool. The northern white rhino is functionally extinct as only two females remain. Using frozen sperm from the last, now deceased male, researchers inseminated a female southern white rhino, creating two hybrid embryos. Are we diluting the northern white rhino genome or preserving a significant fraction of it? “In some instances, maybe it’s better to have a hybrid than it is to have nothing at all” (p. 216).
Besides nuance and balance, Life Changing has several other things going for it. As a comedy writer, Pilcher has a wicked sense of humour. Regarding artificial insemination in cattle breeding, she declares: “Romance is dead, replaced by a glorified bovine turkey baster” (p. 53). Her description of zoologist Mark Carwardine’s encounter with an amorous kakapo simply has to be read; I will just leave you with the words “demented pair of sex-mad avian earmuffs” (p. 290). Sometimes, the humour is acerbic. Industrial animal farming is a major driver of the global decline in biodiversity. If somebody were to populate a new ark to reflect this shift in abundance, she half-jokes, the roll call would go “chicken, chicken, chicken, chicken, chicken, chicken, cow” (p. 353).
Pilcher knows when not to provide too much information. Whole books have been written about e.g. the long-running fox domestication experiment in Siberia, evolution in urban settings and the textbook example of the peppered moth evolving in response to changes in air pollution, the gene-editing tool CRISPR, or the stratigraphical definition of the Anthropocene and what marker will be suitable (it might just be chicken bones). For all of these topics, she manages to provide the relevant details in just a few pages.
“[…] just as humans contain some Neanderthal DNA, studies have shown grizzly bears to contain some polar bear DNA […] It is estimated that the two species have occasionally interbred for the last 40,000 years.”
In other cases, she goes into great detail. This book could be a rather depressing read, so in the last part, she explores in-depth some examples of how our knowledge and technical skills can stem the tide of biodiversity loss. Some researchers have figured out how to make coral spawn on-demand in the lab, allowing the reintroduction of live coral to sites affected by bleaching. There is the intensively managed Kakapo Recovery Program in New Zealand, and the hands-off approach of rewilding, such as the Knepp Estate in the UK. The topic of rewilding is where I find Pilcher at her least critical and most starry-eyed. Although there are places where she hints at human population numbers multiplying our impact, she never mentions overpopulation out loud. And beyond some hints at eating less meat, she does not really address what limits we ought to impose on ourselves if we want large-scale rewilding efforts to exist side-by-side with 8 billion people. Admittedly these are huge and divisive topics without easy answers that are outside of the scope of this book, but they are barely acknowledged here.
In her introduction, Pilcher pithily states: “Life is changing. Humans are responsible“. Life Changing is a very enjoyable piece of popular science writing that shows the many ways in which this is true. I was particularly pleased that, despite my familiarity with the topic, she still had surprises in store for me.
Disclosure: The publisher provided a review copy of this book. The opinion expressed here is my own, however.
Other recommended books mentioned in this review:
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
]]>
What is the price of humanity’s progress? The cover of this book, featuring a dusty landscape of tree stumps, leaves little to the imagination. In the eyes of French journalist and historian Laurent Testot it has been nothing short of cataclysmic. Originally published in French in 2017, The University of Chicago Press published the English translation at the tail-end of 2020.
Early on, Testot makes clear that environmental history as a discipline can take several forms: studying both the impact of humans on the environment, and of the environment on human affairs, as well as putting nature in a historical context. Testot does all of this in this ambitious book as he charts the exploits of Monkey—his metaphor for humanity—through seven revolutions and three million years.
Cataclysms: An Environmental History of Humanity, written by Laurent Testot, published by The University of Chicago Press in November 2020 (hardback, 452 pages)
To be frank, Testot deals with the first 2,988,000 years in the first two chapters. Understandably, as the pace of progress was initially slow, and comparatively little information is available to us from the palaeontological and archaeological records. Thus, he starts his history proper with the agricultural revolution ~12,000 years ago. Given the synthesizing nature of this book, Cataclysms will be a feast of recognition for readers that are familiar with the literature.
Some examples include the near-simultaneous rise of agriculture in several places, with geography playing an important role in which plants and animals were available to domesticate, or the fall of the Late-Bronze Age civilizations in the 12th century BCE. The myth of virgin rainforests and the long history of agriculture practised in the jungle. The microbiological onslaught that accompanied the Columbian exchange when Christopher Columbus and other explorers brought new epidemics to the Americas, or the scourge of mosquito-borne diseases that later decimated European colonialists overseas. The medieval Little Ice Age and the global crises it precipitated, or the worldwide impact of the Tambora volcanic eruption. The Great Acceleration in the 20th century and the recognition of the Anthropocene. All of these have been chronicled at length in books and other publications.
“Given the synthesizing nature of this book, Cataclysms will be a feast of recognition for readers that are familiar with the literature.”
Testot also mentions episodes that I was barely familiar with; partially, I suspect, because he can draw on the French history literature. For example the eruption of the Samalas volcano that seems to have served as a transition between the Medieval Warm Period and the Little Ice Age. Or the 15th-century mining for silver in the Andes and the immense pollution that caused. Or the environmental roots of the expression “mad as a hatter” (it involves the 17th-century beaver trade). Cataclysms sometimes seems to forget it is an environmental history book. Thus, the environment takes a backseat when he describes the Axial Age, the period between 800 and 300 BCE that saw the birth of universal religions and philosophies in both Asia and Europe that are still with us today. Similarly, the chapter charting the rise of money, empires, and trade in Europe and Asia before the Common Era only at the very end examines the environmental impact of it all.
The book’s style might divide opinions. Testot throws all his eggs in the proverbial narrative basket. The book is clearly deeply researched, but the notes section at the end encompasses a mere 16 pages. Testot must have decided that supporting every claim and fact with a footnote would have distracted from the story he tells. Although the references contain many interesting books and publications, those wishing to check up on certain claims will have to do their own research. Furthermore, the book is strikingly devoid of photos, maps, graphs, and tables, bar a single chart of the human world population through time in the appendix. As such, I felt Cataclysms did not deliver on the dustjacket’s promise of providing “the full tally” the way e.g. Vaclav Smil did in Harvesting the Biosphere. Those wanting a more data-driven overview will probably want to check out Cataclysms‘s big contender for 2020, Daniel R. Headrick’s Humans versus Nature. I had the chance to rifle through a copy, though not yet read it in full. At 604 pages with a 100-page notes section (and some illustrations), it promises to be a denser read.
“[The book] will undoubtedly charm newcomers to the field with its narrative style and ambitious scope […] but I suspect that seasoned readers will crave something more dense and data-heavy.”
Testot’s outlook for the future is bleak, though his concluding chapter wanders somewhat aimlessly. Rather than offering an overview of which planetary boundaries we have breached and how far in overshoot we are, Testot focuses on what he calls the upcoming Evolutive Revolution before turning to some likely consequences of climate change. This final revolution could either pan out as the pipe-dream of transhumanism where nano-, bio-, and information technologies converge into the singularity that would make humans immortal / obsolete as Artificial Intelligence takes over (something Testot is critical of), or we may end up as mutants in the chemical cesspit that we are making of our planet. Throw in a conclusion and an epilogue to the English edition that both reiterate main points from the book, and it starts to feel a little bit like Tolkien’s struggle to let the reader go in the last book of The Lord of the Rings.
Environmental history has become a rather crowded subject and opinions will probably be divided on whether Cataclysms stands out from the crowd sufficiently. It will undoubtedly charm newcomers to the field with its narrative style and ambitious scope—Testot knows how to spin a fine yarn and provides an entry point to many fascinating chapters in world history that readers will want to explore further. I certainly enjoyed reading it, but I suspect that seasoned readers will crave something more dense and data-heavy.
Disclosure: The publisher provided a review copy of this book. The opinion expressed here is my own, however.
Other recommended books mentioned in this review:
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
]]>
