Final answer:
The two major periods of hominine evolution are the Pliocene and Pleistocene epochs, with the Pliocene marking the rise of bipedal hominins and the Pleistocene the expansion of Homo species, including modern humans.
Step-by-step explanation:
The two major periods of hominine evolution are generally categorized into the Pliocene and Pleistocene epochs. The Pliocene epoch, from 5 million to 1.8 million years ago (MYA), saw the emergence of bipedal hominins and evidence of primitive cultural behaviors. Notable climate changes, such as colder conditions and alterations in sea levels, facilitated evolutionary adaptations. On the other hand, the Pleistocene epoch, from 1.8 million years ago to 11,700 years ago, featured the rise of various Homo species, including Homo habilis, Homo erectus, as well as the Neanderthals and Denisovans whom modern humans share common ancestry with.
Through these periods, key adaptations such as increased brain size, bipedal locomotion, and the development of cultural practices played fundamental roles in the hominine evolutionary narrative. Homo sapiens, the species to which all modern human beings belong, emerged roughly 200,000 years ago and went on to populate the globe, based on the widely accepted "out of Africa" model. This period saw significant advancements in tool use, social structures, and other forms of cultural complexity.