Antarctica Used to be Too Cold for Penguins.

Emperor penguins are very unique birds. They can survive the frigid Antarctic winter when temperatures hit -60°C (-76°F), and become heat stressed when it's warmer than 0°C (32°F). They congregate on sea ice during the winter breeding seasons, and travel for months at a time at sea for food.  In a study published in Global Change Biology, the study of climate change has revealed that at one point in history, the Antarctic was too cold for emperor penguins. The study also revealed that due to climate change, the Antarctic may end up being too warm the for penguins, causing their populations to decline. 3 emperor penguin populations survived the last ice age. But how was this information attained?

Genetic diversity of ancient and modern emperor penguins was evaluated by collecting genetic samples of 8 breeding colonies. The population history was reconstructed using "mitochondrial DNA from extent colonies and radiocarbon-dated subfossils" and correlated with environmental conditions. The analysis revealed that 12,000 years ago when the ice age ended, emperor penguin numbers began to rise with the increase in temperature and decrease of sea ice. The conditions have to be just right for them. Too much sea ice means difficulty searching for food, and too little means difficulty breeding.

While I am glad that genetics can be used in a historical way, such as this, I am a little upset with the realization of global warming. We all hear about it and know about it, and it's even more upsetting that we can confirm the damaging effects using genetic analysis. Genetics has proven that these birds rely on certain climate requirements in order to thrive. It's just a shame that more cannot be done to help them proliferate.

Original Article: Too much of a good thing: sea ice extent may have forced emperor penguins into refugia during the last glacial maximum