Historian Frederick Jackson Turners famous 1893 premise of the significance
of the frontier in American history argued that the struggle to conquer
the vast American continent with its unique mixture of challenge and
opportunity had been crucial in the formation of the American character.
He also declared that this frontier was gone. Even if you accept Turners
thesis (and many historians dont), it is reasonable to ask what happens
when frontiers vanish or change when the opportunities and challenges
are different or are no more.
Paleontology underwent a major expansion of theoretical frontiers over the last quarter of the 20th century, resulting in the birth of modern paleobiology. But despite that growth and the continuing popularity of dinosaurs among the general public, academic paleontology was also widely viewed as a field in decline among the geosciences, due mostly to the apparently irreversible retrenchment of the use of fossils to date rocks in the search for petroleum. In November 1993, I felt compelled to defend on this very page the indispensability of paleontology.
A lot has changed since then. Through a combination of new technology, new fossils and theoretical refinement, paleontology is once again in the midst of a ferment of new ideas and opportunities, as well as challenges. A hypothetical dream team of paleontologists for the next decade or two would come from a number of fields.
Astrobiology once only science fiction for example, is now a large part of the motivation for the most talked-about science story of 2004 and the proposed future for manned space flight. The success of the rovers Spirit and Opportunity in finding evidence for liquid water formerly on Mars has laid the groundwork, and it is entirely plausible that within the careers of present researchers, we will be examining fossils from Mars. In the meantime, paleontologists will continue to play a major role in laying out the environmental conditions in which life might have arisen on other worlds.
Back on Earth, we have yet to synthesize a coherent theory of how ecology matters to long-term evolutionary change. Once we better understand that connection, we will better be able to understand diversity changes at critical points of biological turnover (episodes of both origination and extinction) throughout time, including the Cambrian Explosion. Fueled by new fossil discoveries, new paleoenvironmental data, and new insights from developmental biology, understanding this burst in diversity 545 million years ago is the single hottest field in paleontology right now and shows no sign of cooling off any time soon.
Paleontologists are also increasingly interfacing with life scientists, linking developmental biology to evolutionary biology. This interface known as evo-devo is a major locus of current activity on classical paleontological topics like the Cambrian Explosion and the origin of the phyla and one of the great growth fields in paleontology today. In its focus on the role of internal constraints in evolution, it is also likely the ultimate destination of much of Stephen J. Goulds legacy.
Paleontologists, of course, are students of the past, but we are also increasingly being seen as useful prognosticators of the present and future. In the early 1980s, E.O. Wilson and a few others first began to compare extinctions going on today with those of the geologic past. Few took the comparisons seriously. Now the sixth extinction is a common term for the current biodiversity crisis, and it is widely appreciated that paleontology has real insights to offer to its understanding and remediation. What Karl Flessa has usefully called conservation paleobiology includes studies as diverse as recovery from mass extinction and paleoecology. The Shifting Baselines initiative (www.shiftingbaselines.org), is providing stark warnings of our impending environmental degradation and resulting descent into a world resembling the Proterozoic a world of slime, devoid of complex life.
Biology is also contributing to paleontology through the explosion of information made possible by genetic sequencing. Paleontology will not only continue to benefit from having molecular family trees of particular groups, but it also will continue to be essential for establishing the timing of events of molecular evolution and for putting family trees based only on living taxa into larger evolutionary contexts. Among my graduate students, it is a popular parlor game to imagine what we (and especially they) will all be doing when everything is sequenced. They need not worry: Integrating fossils and molecules will be both a major challenge and an enormous opportunity for paleontology for the foreseeable future.
Although it has been talked about for many years, we are now seemingly on the threshold of a true cyber-infrastructure for paleontology. Initiatives like CHRONOS, the Paleobiology Database, NMITA (Neogene Marine Biota of Tropical America), the Paleontology Portal and interconnected collections databases are no longer demonstration projects and have real potential to produce important insights in the next few years. The work of the Paleobiology Database group, for example, is reevaluating the history of the diversity in the seas over the past 540 million years, which has been arguably one of the dominant topics in paleobiology over the past 25 years (see story, page 28, "25 Years of Mass Extinctions and Impacts").
Meanwhile, the geosciences in general continue to move toward the notion of a global, integrated view of Earth as a set of interacting systems. A number of geoscience departments have accordingly embraced global change or earth systems science as new focuses of their research and efforts to increase undergraduate majors. These programs are major opportunities for paleontology: You simply cannot have a program in these areas without including an understanding of the role of life and its history.
The frontiers of paleontology are once again spread far and wide across the landscape. The coming years have every sign of being a time of excitement, discovery and intellectual ferment along our stretch of these new unexplored continents.