Final answer:
The 'Early Homo' period from 2 million to 300,000 years before present saw significant evolutionary changes in hominins, including adaptations in teeth and diets in response to environmental changes, as well as advancements in tool technologies and early migrations out of Africa.
Step-by-step explanation:
Early Archaic Homo and Environmental Changes
The time frame referred to as Early Homo spans from approximately 2 million years before present to 300,000 years before present. During this period, hominin species such as Homo habilis, Homo erectus, and Homo antecessor evolved and adapted to various environmental pressures. An important adaptation in this time frame was in dentition, reflecting dietary changes.
Environmental changes during the Early Homo period included fluctuating climates and habitats. These changes prompted early humans to adopt varied diets and more complex tool use. Homo erectus shows evidence of a shift towards meat consumption, evidenced by the expensive tissue hypothesis, which suggests that the energy demands of larger brains required nutrient-dense food sources like meat. As a result, changes in teeth adaptation occurred, with smaller jaws and front teeth developing in Homo sapiens, indicative of a varied diet that was easier to process than the earlier, tougher plant-based diets.
Throughout the Lower Paleolithic and into the Middle Paleolithic, tool technologies evolved from simple Oldowan tools to more sophisticated Acheulean and then Mousterian tools, which matched the environmental and subsistence demands of the hominins. Early hominin migrations, driven by environmental changes and the search for food, saw the spread of Homo species out of Africa into Asia and Europe, marking a significant era in human evolution and migration.