Answer: An invisible boundary separating the ecozones of Asia and Australia
Notes: The Wallace Line is an invisible boundary separating Asian and Australian animal species. It was first identified by English naturalist Alfred Russel Wallace in the 19th century. The line runs through the Malay Archipelago, between Bali and Lombok, and between Borneo and Sulawesi. Asian side species (Borneo, Bali) resemble mainland Asian animals like tigers and monkeys. Australian side species (Sulawesi, Lombok) resemble Australian wildlife like kangaroos and cuscuses. Scientists now view it as a transition zone rather than a strict boundary. Climate change and habitat destruction threaten these ecosystems and species adaptation.
