by Laura Geggel, Staff Writer | March 03, 2015 07:29am ET
Earth's last ice age was so cold that even Antarctica's emperor penguins had trouble with the chill, a new study finds.
Just three populations of emperor penguins (Aptenodytes forsteri) likely survived the last ice age, which occurred from about 19,500 to 16,000 years ago, with one such population likely setting up a refuge in the Ross Sea, an Antarctic body of water southeast of New Zealand, the researchers said.
In the study, the researchers examined how climate change affected emperor penguins during the past 30,000 years. They looked at the genetic diversity of modern and ancient populations of emperor penguins in Antarctica, and estimated how it had changed over time. (To determine the penguins' ancient genetics, the researchers looked at radiocarbon-dated subfossils — the remains of emperor penguins that were not fully fossilized.)