Climate models predict a nearly ice-free
When cold conditions returned, the Arctic route was cut off, mostly by a lack of food. As the ice melts, productivity in the
Vermeij and Roopnarine reviewed literature on mollusks found in the Bering and Chuckchi seas between
Three factors drove the one-way traffic across the North Pole during the Pliocene, Vermeij said. The Bering and Chukchi seas are very productive, with abundant food; there is a net northward flow of water from the Pacific through the
But the invaders will not wipe out native species, Vermeij said. The fossil record shows that invasions rarely lead to species extinction in marine environments, he said. Instead, the invasion will add new species and hybrids and increase competition in the
"The composition and dynamics of north Atlantic communities will change," Roopnarine said. "But whether that will help or harm local fisheries is an open question. Humans may have to adapt as well."
In the paper, Vermeij and Roopnarine note that in the past, species expanded their ranges within and between oceans during warm periods.
"The interesting thing to me is that the fossil record has something to say about the consequences of global warming, " Vermeij said.
The article is published in the Aug. 8 issue of the journal Science.
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