Final answer:
The earliest fossil evidence for Homo erectus in Western Europe is from 1.2 mya found at Sima del Elefante, providing key insights into early human migration and evolution.
Step-by-step explanation:
The earliest fossil evidence for Homo erectus in Western Europe dates from 1.2 million years ago, from Sima del Elefante. This is indicated by the discovery of Homo antecessor, which some scientists consider to be an ancestor of Homo heidelbergensis. These fossils provide insights into human evolution and Homo erectus's migration patterns out of Africa, reaching as far as Western Europe and Asia. The remains represent some of the earliest evidence of the genus Homo in Europe.