The Miocene Arctic
Geographically, the Arctic was once very different. Instead of the archipelago of today, the Arctic of the Miocene comprised a continuous land mass that was connected with Greenland and the rest of North America. Arctic land also linked the continents now known as Asia and North America for most of the last 100 million years. When conditions were favourable, it would have served as a "highway" between the continents, thereby facilitating species distribution into new areas. It also prohibited dispersal of marine taxa between the Arctic Ocean and the North Pacific. There have also been shorter-lived land connections between North America and Europe across the North Atlantic.
Climatically, the Arctic has seen much change. In the long view, the Miocene Arctic was a world in transition. The climate was warm—warmer than today—but it had been cooling for millions of years. New habitats emerged, and warm-adapted plants and animals would have moved southward, or adapted to the changing environment. Plants and animals that managed to survive in the cooling Arctic may have been pushed onto new evolutionary paths.
Because of intercontinental connections and changing climate, biodiversity in the Arctic would have experienced changing selective pressures. Mammals would be able to disperse between Asia and North America only if they could tolerate the High-Arctic climate. For some mammals, their evolutionary path may have been altered to allow them to survive in the deteriorating Arctic conditions. The effects of changing climate and biodiversity in the Miocene Arctic would have influenced the biodiversity of the southern latitudes, and even influenced the biodiversity that we see around us today. One of the questions that impels Rybczynski's research is, "How big was this Arctic effect?"
In many ways, northern polar research has lagged behind research in more southerly regions. Much of this is due to the very real logistical challenges presented by the remoteness and severe climate of the Arctic. Even until well after the Second World War, geological and palaeontological research in the Arctic was still done by small parties using dog teams. Unsurprisingly, much of the Arctic remains unexplored scientifically. The tide is beginning to turn, however: small aircraft and increased governmental support for Arctic research have helped open the region to further scientific exploration. The Arctic is taking its place as a vitally important region for the study of life of the far distant past.
Research in the Arctic Archipelago has found remarkable fossil evidence. Discoveries range from new and unusual kinds of vertebrates, such as Tiktaalik, the Devonian relative of land dwelling vertebrates, to the remains of verdant prehistoric forest ecosystems with no modern analogue. Recent outstanding finds such as Puijila suggest that we have only scratched the surface. The opportunities are rich for Rybczynski's further research: searching for more fossil clues to evolutionary patterns and investigating the relationship between changing biological systems and the environment.