If greenhouse gas emissions continue at current rates, scientist predicts that the Arctic Ocean could be completely free of permanent sea ice. The sea ice acts as a barrier which separates many marine mammal populations. With the loss of the ice, populations which have been isolated from each other for millennia could potentially interbreed. This could result in the disappearance of unique, adaptive characteristics.

"By melting the seasonal ice cap, we're speeding up evolution. People often talk about species adapting to climate change, but the kind of adaptation that's necessary is a change toward genes that fit the new climatic environment better than the old genes. Individuals don't adapt genetically. Populations do. That requires generations, which requires time. But we're talking about losing the Arctic summer sea ice in a matter of a few decades. So the time for adaptive response may not be there," lead author and NOAA scientist Brendan Kelly told OnEarth.org.