Using past extinctions to drive future conservation

Late Quaternary extinctions of large animals have historically been understood as global phenomena, resulting from climate fluctuations or quickly dispersing human populations. However, new technologies are enabling fine-grain analyses that shed new light on individual species' varied responses to changing local conditions, new competitors and predators, and other external drivers. According to an interdisciplinary team writing in BioScience, the newly gained knowledge may be of particular value in understanding animal populations' responses to contemporary threats, as well--in particular, those posed by climate change.

The giant sloth eremotherium displayed at the Royal Ontarior Museum
[Credit: Brian Switek, Nat.Geographic]

Jillian A. Swift of the Bishop Museum and her coauthors focus on five key innovations--radiocarbon approaches, stable isotope analysis, ancient DNA, ancient proteomics, and microscopy--describing the ways in which new technologies are elucidating past extinctions. For instance, the authors describe the stable isotope analysis of a single tooth belonging to an extinct ground sloth from Belize. The data showed "how this individual varied its diet in response to seasonal fluctuations within a single year, granting high-resolution evidence for the ability of this species to adapt to climate-driven vegetation changes."

Similarly, new methods may help in capturing the varied responses to changing conditions, some of which may be contrary to traditional expectations. The authors note that "bison (Bison priscus), wapiti (Cervus canadensis), and moose (Alces alces), increased in abundance before and during Late Pleistocene human colonization of Alaska and Yukon Territory in North America."

Past responses to various disruptions are already informing present approaches to ecosystem management, say the authors. They highlight the work of Louys and colleagues, who drew on detailed histories of tropical megafauna and "evaluated the ranges and ecological roles of nine megafaunal taxa during the Pleistocene to assess their viability for rewilding efforts, including species translocations, reintroductions, or range expansion," ultimately selecting orangutans, tapirs, and Tasmanian devils as the best suited to rewilding and ecosystem restoration in the Asia-Pacific region.

As perturbations grow in number and severity, say Swift and her colleagues, the "application of diverse methodologies to such records will only further the resolution of attempts to connect insights from the past to concerns in the present, enabling archaeology and paleontology to make a meaningful contribution to species and habitat protection or, where desired, reestablishment."

Source: American Institute of Biological Sciences [October 02, 2019]