Conservation paleobiologists – scientists who use the fossil record to understand the evolutionary and ecological responses of present-day species to changes in their environment – are putting the dead to work.
"The fossil record was there recording changes in the environment and species' responses to those changes long before any ecologists were taking notes," said Karl W. Flessa, University of Arizona professor and head of geosciences.
Information gleaned from the geologic record can help solve current problems in conservation biology, according to Flessa and his co-author Gregory P. Dietl of the Paleontological Research Institution and Cornell University, both in Ithaca, N.Y.
The two conservation paleobiologists have just published a review of the research in their emerging field. Their review shows that the fossil record can be used to assess environmental impact, predict which species will be most vulnerable to environmental changes and provide guidelines for restoration.
Studying fossils, sediments and local geochemistry by using the tools of paleontology can peer into the past to reveal the ecological circumstances that caused the demise of some species yet allowed others to thrive, according to the authors.
"Such data are crucial for documenting the species we have already lost – such as the extinct birds of the Hawaiian islands – and for developing more effective conservation policies in the face of an uncertain future," said Flessa, who is also the director of the UA's School of Earth and Environmental Sciences.
First author Dietl said, "A conservation paleobiology perspective has the unique advantage of being able to identify phenomena beyond time scales of direct observation." Dietl is the director of collections at the Paleontological Research Institution.
Dietl and Flessa's literature review, "Conservation paleobiology: putting the dead to work," is published in the January issue of the journal Trends in Ecology and Evolution. The National Science Foundation funded the research.
Most conservation planning is derived from modern-day observations alone – which may not accurately predict the responses of species to future environmental changes, according to Dietl and Flessa. Therefore, geohistorical records are critical to identifying where – and how – species survived long-ago periods of environmental change.
The researchers cite the example of how the arctic fox, Alopex lagopus, responded as the Earth warmed at the end of the Pleistocene, 12,000 years ago. Ancient arctic fox DNA has shown the species did not alter its range as the climate warmed and became extinct in Europe at the end of the Pleistocene. However, the species persisted in regions of northeastern Siberia where the climate remained cold enough for the foxes.
In another tale from the beyond, fossil evidence suggests the birds of the Hawaiian Islands suffered large-scale extinctions around the time the Polynesians arrived, particularly the larger-bodied and flightless, ground-nesting species. The pattern suggests that hunting by humans played a role in the extinction of the flightless species.
When the first Europeans arrived in the 18th century, most large-bodied birds had already disappeared. A second wave of extinctions followed European colonization of the islands.
"Conservation research too rarely makes use of geohistorical data," said H. Richard Lane, program director in the National Science Foundation Division of Earth Sciences. "Most such studies focus on short timescales ranging from years to decades. Looking back farther – much farther – in time may be crucial for comprehending events unfolding today."
An important role of geohistorical data is to provide access to a wider range of past environmental conditions – alternative worlds of every imaginable circumstance.
Dietl and Flessa also cite a study on insect damage to fossil plant leaves in the Bighorn Basin of Wyoming before, during and after the Paleocene-Eocene Thermal Maximum, or PETM, which occurred some 55.8 million years ago. The research showed that herbivory by insects intensified during the PETM global warming episode.
The PETM, scientists believe, is one of the best deep-time analogs for current global climate change because during that time, global average temperatures rose by 9 to 14 F (5 to 8 C) in less than 10,000 years.
The finding suggests how human-induced rise in atmospheric carbon dioxide is likely to affect plant-insect interactions in the future, something that cannot be determined by short-term studies, the authors wrote.
The dead can help even in remote places like the Galapagos Islands.
Paleobiologists have used fossil pollen and plant records to show that at least six non-native or "doubtfully native" species were present before the arrival of humans. This baseline information, Dietl said, "is crucial to a current conservation priority in the Galapagos: the removal of invasive species."
The past may lead to better conservation practices that are crucial for life, not death, on Earth.
The dead, it turns out, do tell tales.