Easter Island is known best for its hundreds of colossal stone statues depicting human figures. The causes of its societal and economic collapse centuries ago are fiercely debated among scientists. Luis C. Cobo/Flickr hide caption

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A Filipino chicken vendor in Quezon City, east of Manila, Philippines. Researchers say Pacific island chicken are genetically similar to the variety found in the Philippines, but different from South American chicken. Rolex Dela Pena/EPA/Landov hide caption

toggle caption Rolex Dela Pena/EPA/Landov