Evolution penguin initiated by Antarctic ice

Nieuws | de redactie
19 april 2013 | The origin of the Antarctic ecosystem can be traced back to the emergence of the Antarctic ice sheets 33.5 million years ago, research from Utrecht University shows. The development of a sea-ice ecosystem triggered further the evolution of whales and penguins.

In 2010 the Integrated Ocean Drilling Program (IODP) took, for the first time, long complete sediment cores from the seafloor along the Antarctic margin south of Australia. Previous studies on these sediment cores demonstrated that subtropical plants covered Antarctica about 53 million years ago. The current study focuses on a time period 20 million years later. During these 20 million years, the climate gradually cooled, until large ice sheets appeared on Antarctica 33.5 million years ago.

The researchers studied fossils of single-celled dinoflagellates, a family of in marine plankton, in sediment cores. They found that when Antarctica was sub-tropical and ice-free, the seas were inhabited by a diverse array of dinoflagellates that are characteristic for relatively warm climates. However, from the moment that the ice cap came into existence the diversity demised and only species are found that are at present associated with sea-ice environments around Antarctica

Unique sea-ice ecosystem
“Today, the seas around Antarctica play a critical role in the oceanic food web. Strong algal blooms only occur in summer, when the sea-ice melts. These blooms are a key food-source for both small single-cell organisms such as certain species of dinoflagellates and for larger organisms”, explains researcher Sander Houben of Utrecht University.

 “We believe that the sudden change in the ecosystem of the Antarctic waters as indicated by the sudden appearance and dominance of these dinoflagellate species was connected with the development of sea-ice conditions. This was not only critical for climate, but also for biology. Larger sea animals probably adapted their diet because the algal growth season became shorter and more intense. We therefore believe that it is no coincidence that the evolution of modern whales and penguins approximately corresponds with the emergence of the ice sheets.” These results stress that major climate change is often accompanied by rapid biological evolution.

Schrijf je in voor onze nieuwsbrief
ScienceGuide is bij wet verplicht je toestemming te vragen voor het gebruik van cookies.
Lees hier over ons cookiebeleid en klik op OK om akkoord te gaan