Final answer:
Bipedalism is walking on two legs and is key to human evolution, with changes such as the angling of the femur and the development of spinal curves and foot arches. Early Homo species were highly adept at bipedal locomotion, and it may have conferred several advantages. H. floresiensis had a unique walking style, while other factors like brain size and tool-making abilities are also considered in classifying the genus Homo.
Step-by-step explanation:
The major component of being human, bipedalism, involves numerous anatomical changes that have occurred since our earliest hominin ancestors. Bipedalism refers to walking on two legs, where during locomotion one leg is the stance leg and the other is the step leg. Key anatomical features for successful bipedal locomotion include the angling of the femur inward to maintain balance, the evolution of spinal curves to balance the upper body's weight, the development of the foot arch, and the alignment of the big toe.
Various hypotheses have suggested that the benefits of bipedalism may have included increased energy efficiency, improved thermoregulation by exposing more of the body's surface, and the ability to free up hands for carrying tools or offspring. By 2.8 million years ago, early Homo species, such as Homo erectus, were nearly as efficient at bipedal locomotion as modern humans despite their larger jaws and smaller brains. H. floresiensis, however, had a unique form of bipedalism due to differences in leg bone thickness and foot structure.
In addition, other criteria beyond bipedalism used to classify a species under the genus Homo include brain size, dexterity for making tools, and bone structure changes. Ultimately, bipedalism is a defining characteristic of humanity and a key focus for anthropologists studying human evolution.