The indigenous people of Tasmania are clearly related to the indigenous people of Australia, but were separated from them when the land bridge between Australia and Tasmania disappeared approximately 10, 000 years ago. Two thousand years after the disappearance of the land bridge, however, there were major differences between the culture and technology of the indigenous Tasmanians and those of the indigenous Australians. The indigenous Tasmanians, unlike their Australian relatives, had no domesticated dogs, fishing nets, polished stone tools, or hunting implements like the boomerang and the spear-thrower. Each of the following, if true, would contribute to an explanation of differences described above EXCEPT: ['Indigenous people of Australia developed hunting implements like the boomerang and the spear-thrower after the disappearance of the land bridge.', 'After the disappearance of the land bridge the indigenous Tasmanians simply abandoned certain practices and technologies that they had originally shared with their Australian relatives.', 'Although the technological and cultural innovations were developed in Australia more than 10, 000 years ago, they were developed by groups in northern Australia with whom the indigenous Tasmanians had no contact prior to the disappearance of the land bridge.', 'Devices such as the spear-thrower and the boomerang were developed by the indigenous Tasmanians more than 10, 000 years ago.']