What is the Wallace Line?
The Wallace Line is an imaginary line in Indonesia between Borneo and the island to its immediate east, Sulawesi. The line has ecological significance because it separates two zoogeological regions that are respectively associated with Asia and Australia. To the west of the line, fauna is more Asian. To its east, it more closely resembles the Australian fauna. The reason for the line is a deep oceanic trench that has preserved the gulf between these two islands for millions of years. Without it, they would have been periodically connected as Ice Ages caused the sea level to lower by as much as 120 meters (394 ft), connecting together Borneo with the Asian mainland and Sulawesi with Australia. The region around the Wallace Line is often considered among the most ecologically diverse in the world, alongside the Amazon Rainforest and Congo Rainforest. This region adjacent to the Wallace Line is often called Wallacea. The region is home to over 10,000 plant species, 15% of which are endemi
