When Felisa Smith, professor of Ecology and Evolutionary Biology at The University of New Mexico, explains what her new book is about, she quotes Churchill and Shakespeare. The book, Mammalian Paleoecology: Using the Past to Study the Present, will be released this month by Johns Hopkins University Press.
"Fundamentally, my book is about the importance of past earth history. Winston Churchill famously once said, 'The nation that forgets its past has no future.' This quote is just as applicable to science. Many of the pressing environmental problems we face today have an analog in the past. Thus, by examining how animals, plants and ecosystems responded to past perturbations ̶ be they climate or biodiversity loss ̶ we can gain insights useful for effective conservation and management."
Classic paleontology has focused on the study of fossils and the reconstruction of lineages of extinct species. But as diverse fossils of animals and plants were unearthed and catalogued, it became possible to reconstruct more elaborate ecosystems, tying together plants, animals, and geology. By the second half of the 20th century, this effort gave birth to the field of paleoecology ̶ the study of the interactions between organisms and their environments across geologic timescales.
In the book, Smith looks at all mammals, big and small, and how the past mirrors the present.
"While I talk about their entire evolutionary history from 210 million years ago to present, much of the book is concerned with the past 20,000 years. This emphasis is because that time period, the terminal Pleistocene, is a good proxy for modern environmental problems. That is, this time frame encompassed substantial environmental change like the end of the last ice age, abrupt climate events, and biodiversity loss with the extinction of the megafauna," she explained.
Reflecting on what the past can teach us, she said, "To provide another quote, my lab motto is from Shakespeare: 'What's past is prologue.' That is, the big environmental problems of climate change and biodiversity loss have happened in the past."
Mammals evolved around 210 million years ago, so they co-existed with dinosaurs until the latter went extinct 66 million years ago. But, for much of this time, mammals were pretty small and fairly insignificant in ecosystems. It wasn't until the extinction of non-avian dinosaurs that mammals diversified into the diverse variety of forms and shapes we have today.
"Using the past, we can ask about the type of responses animals had to climate. We can characterize the thresholds where animals were able to adapt in situ, and see how fast they were able to shift their geographic distributions in response to shifting climate. We can even characterize the 'unraveling' of ecological interactions within a community. The animals around today were also the species present during the last ice age and its aftermath, so this time period is particularly relevant."
Smith recommends her book for undergrads, grad students, and anyone else interested in paleoecology.
"I tried hard to make it readable whilst still providing academic rigor; I hope I succeeded in this," she concluded. Apparently she has.
"A tour de force," reads one review. "One of the world's most eminent evolutionary biologists, Felisa Smith synthesizes paleontology and ecology to tell the story of mammal evolution and put today's environmental crisis into the perspective of Earth history. Both readable and authoritative, this book is invaluable for anyone looking to understand how real organisms respond to real moments of environmental change."
Mammalian Paleoecology: Using the Past to Study the Present will be available online from Johns Hopkins University Press.
