The 175th annual meeting of the American Association for the Advancement of Science (AAAS), publisher of the journal Science, opened in Chicago on Thursday.

The theme of the meeting is "Our planet and its life: Origins and Futures."

The opening ceremony paid tribute to the 200th anniversary of Charles Darwin's Birth, as well as the 150th anniversary of his famous publication "On the Origins of Species by Means of Natural Selection."

The five-day gathering is expected to draw up to 10,000 people from 60 countries, said the organizer.

Often dubbed "the Olympics of science conferences," the AAAS meeting this year offers a blend of 175 symposia, seminars, lectures, as well as other events in diverse scientific fields. Taking the center stage will be climate change, sustainable development, earth and life evolution and science literacy.

"Today, the warming of our planet is unequivocal, and human activities are a primary cause," said James J. McCarthy, president of the AAAS. "Global climate change is real, humans are responsible for a substantial part of it, and it's taking us in dangerous directions."

Founded in 1848, the AAAS, the world's largest general scientific society, serves 262 affiliated societies and academies of science, representing 10 million individuals. Its publication Science has an estimated total readership of 1 million.

(Xinhua News Agency February 13, 2009)