I recently watched the science fiction film Jurassic Park (the original, 1993 version) with my two daughters. One of them asked me whether or not it was possible to clone a dinosaur such as a Tyrannosaurus rex. I of course responded with a gentle “No sweetheart, it is not possible. However, scientists currently do have the technology to reengineer organisms which have recently gone extinct.” In short, in order to clone an organism, one would need genetic material from a living cell with an intact genome. My daughter's question sounded like stuff I could only dream of as a child. Not to sound overly dramatic, however, we are living at a time when science and science fiction are becoming more and more difficult to decipher. This book provides both the scientist and science fiction enthusiast with the necessary tools to distinguish between the two.

Recent polling data indicate that the public is generally more supportive of animal cloning than of human cloning, but almost two-thirds of Americans oppose the cloning of animals. This book is more about bringing to light the basic science, while at the same time exploring the ethical ramifications of resurrecting or reviving a lost species. For example, the woolly mammoth; the bucardo, a kind of wild goat from the Pyrenees mountains; the auroch, wild ancestor of domestic cattle; the Tasmanian tiger; and the passenger pigeon are candidates for, as Shapiro states throughout the book, “bringing species back through de-extinction.”

While reading the prologue of How to Clone a Mammoth, a couple of questions quickly become inevitable: (1) how do you go about cloning extinct organisms and (2) what's the point? The first chapter (“Reversing Extinction”) begins with an overall introduction about the case for de-extinction and the current extinction rate among certain species of organisms on Earth, which some scientists have labeled as the “sixth mass extinction event!” Shapiro states that “Many technical hurdles stand in the way of de-extinction. While science will eventually find a way over these hurdles, doing so will require significant investment in both time and capital. There will be important issues to consider about animal welfare and environmental ethics…. [T]he cost to society of the research needs to be weighed against the gains to society of what might be learned or achieved.” In chapters 2 and 3, Shapiro discusses the science and rationale for selecting or “restoring” a particular species and finding a well-preserved specimen. The author also does a great job in addressing “cloning or de-extinction misconceptions” such as cloning of organisms that do not contain viable, if any, DNA.

In chapters 4–7 (“Creating a Clone,” “Breeding Them Back,” “Reconstructing the Genome,” and “Reconstructing Part of the Genome”), Shapiro clearly analyzes the surprising, cutting-edge molecular biology techniques being used today, in order to resurrect or “restore the past.” For example, a new, inexpensive, molecular tool known as CRISPR (“clustered regularly interspaced short palindromic repeats”)/Cas9 is explored. In short, applications of CRISPR technology include personalized medicine and DNA editing, which involves editing or reassembling parts of an extant organism's genome in order to restore or revive a closely related extinct organism. Shapiro goes on to explain that accomplishing the aforementioned goal is no easy task – but it is one that is becoming more possible thanks to technologies such as CRISPR!

With this realization in mind, chapters 8–10 (“Now Create a Clone,” “Make More of Them,” and “Set Them Free”) summon readers to examine current cloning techniques along with specific organisms that have been cloned thus far. In doing so, Shapiro discusses the promise of cloning technology and how it can be applied to medicine and conservation biology. She makes it clear from the start that it is not her intention to argue for de-extinction in order to only satisfy our curiosity about bringing extinct organisms back. Rather, she wants the reader to appreciate and enjoy the marvels of the “applications of re-engineering technology as they pertain to applications in medical fields and conservation biology.”

In the final chapter (11: “Should We?”), Shapiro explores the “big picture” implications and questions that originate from the science of de-extinction, including these: Is there the possibility of reviving dangerous pathogens? How should we prioritize the conservation of species that are alive today? Can the possibility of releasing new species or previously existing species into the wild destroy existing ecosystems?

This is a very engaging and thought-provoking book that tackles some of the most fundamental scientific and ethical questions of our time. How to Clone a Mammoth provides us the opportunity to explore the aforementioned themes in an informed way. In doing so, Beth Shapiro leaves us with the following question: “How will the world react when the first genetically engineered elephants are strolling casually through Pleistocene Park? I can't wait to find out.”