Final answer:
Modern humans differ from earlier hominins by having smaller faces and jaws, larger brains, a more vertical forehead, and reduced brow ridges. Homo sapiens evolved from Homo erectus and other archaic Homo species, which had more pronounced facial features and smaller brains relative to their body size. Modern humans' feet and skeletal structure are also fully adapted for efficient bipedal locomotion.
Step-by-step explanation:
Modern humans, known scientifically as Homo sapiens, exhibit several morphological differences compared to earlier hominins like Homo erectus, Homo habilis, and the various species grouped under the category of archaic Homo. While early Homo species such as Homo erectus were quite proficient at bipedal locomotion, similar to modern humans, they displayed significant differences particularly from the neck up. Early hominins typically had bigger jaws and teeth, a sloping forehead, and a smaller brain relative to their body size.
Homo sapiens evolved around 800,000 years ago with significant changes such as smaller faces, jaws, and front teeth but with substantially larger brains. Over time, these morphological changes have been associated with advancements in technology, diet, and social structures. The Homo erectus, for instance, had a pronounced brow ridge and a nose that pointed downwards, unlike the more vertical nose of modern humans. Archaic Homo, which are considered transitional between H. erectus and H. sapiens, are characterized by their thick skulls, pronounced brow ridges, and the absence of a prominent chin—traits that are not present in modern humans.
Furthermore, modern humans have a more globular skull shape, reduced prognathism, and feet that are fully adapted for bipedal walking with arches and humanlike ankles. Other species, such as Homo heidelbergensis, Homo rhodesiensis, and Homo neanderthalensis, show an evolution towards these modern features but still retain archaic characteristics, demonstrating the gradual transition over hundreds of thousands of years.