bipedalism

Examples of bipedalism in the following topics:

• Early Human Evolution

  • Hominins, who were bipedal in comparison to the other hominoids who were primarily quadrupedal, includes those groups that probably gave rise to our species: Australopithecus africanus, Homo habilis, and Homo erectus, along with non-ancestral groups such as Australopithecus boisei.
  • In the intervening years, several more specimens of Ardipithecus, including a new species, Ardipithecus kadabba (5.6 million years ago), demonstrated that they were bipedal.
  • Again, the status of this genus as a human ancestor is uncertain, but, given that it was bipedal, it was a hominin.

• Early Homo

  • Though the intelligence of these early hominins was probably no more sophisticated than that of modern chimpanzees, the bipedal (two-legged) stature is the key evidence that distinguishes the group from previous primates, who were quadrupeds (four-legged).
  • Before the discovery of pelvic material of australopithecines, scientists believed that bigger brains preceded bipedalism.
  • However, this was shown to be incorrect: bipedality long antedated dramatic brain increases in hominins.

• Early Hominins

  • A key feature that Australopithecus had in common with modern humans was bipedalism, although it is likely that Australopithecus also spent time in trees.
  • It had a slender build and was bipedal, but had robust arm bones and, as with other early hominids, may have spent significant time in trees.

• Primates

  • The first major morphological change was the evolution of a bipedal locomotor adaptation from an arboreal or semi-arboreal one (upright walking capabilities), with all its attendant adaptations (a valgus knee, long legs relative to the arms, reduced upper-body strength).
  • In body size and cranial capacity, australopithecines were similar to chimpanzees, but they were ancestral to humans because they were bipedal.

• Homo sapiens

  • Humans are distinguished from other primates by their bipedal locomotion and by their relatively larger brain with its particularly well-developed neocortex, prefrontal cortex, and temporal lobes, which enable high levels of abstract reasoning, language, problem solving, and culture through social learning.

• Animal Body Planes and Cavities

  • Shown are the planes of a quadruped goat and a bipedal human.

• Evolution of Birds

  • The second group, bipedal predators called theropods, includes the ancestors of modern birds.