Final answer:
The discovery timeline of Homo erectus fossils includes finding Java Man and Peking Man in Asia and the earliest European Homo fossils, Homo antecessor. Mary Leakey's discovery of bipedal footprints from 3.5 million years ago and the recent Homo naledi find have added depth to our understanding of early hominins and their behaviors.
Step-by-step explanation:
The discovery of Homo erectus fossils has been pivotal in understanding human evolution. H. erectus appeared approximately 1.8 million years ago, originating from East Africa before migrating out of the continent. This species had a larger brain and size, similar to that of modern humans, and displayed less sexual dimorphism.
Significant fossils such as the "Java Man" and "Peking Man" have been found in various locations including India, China, Java, and Europe. For instance, the "Peking Man" fossils discovered in China represent some of the first evidence of H. erectus in East Asia. In addition, the first fossil evidence for the genus Homo in Europe is represented by Homo antecessor, which dates to around 1.2 million to 800,000 years ago.
The fascinating discovery by Mary Leakey of a 75-foot trail of footprints in East Africa, dating back 3.5 million years ago, suggests bipedal hominins such as Australopithecus afarensis. More recent finds, like Homo naledi, challenge our understanding of the genus Homo, with evidence showing that this species may have intentionally deposited their dead in caves, a behavior once thought to be unique to later humans. These discoveries, with the ongoing analysis and research, continue to shape the debate on the origins of anatomically modern humans.