"The lower spine of humans is highly specialized for habitual bipedalism
, and is therefore a key region for assessing whether this uniquely human form of locomotion was present in Oreopithecus," says Shapiro, a professor of anthropology.
That an Ardipithecus-type foot should persist so late suggests our early ancestors trod a more tortuous evolutionary path towards full bipedalism
than previously thought, said team member Bruce Latimer, of Case Western Reserve University in Cleveland, Ohio.
Tool-use also fit with the distinctive trait of walking upright: bipedalism
apparently freed the hands to do their important work (Darwin, 1871, I., pp.
must have also favored (Corballis, 2009) the emergence of this new form of communication for it liberated the hands, allowing for a more elaborated and varied gesticulation.
Walking is our most fundamental mode of transportation, an ordinary act with a long human history, whether you commence that history some six million years ago with the origins of bipedalism
(Plato called man "a featherless biped") or religion ("And they heard the voice of the LORD GOD walking in the garden in the cool of the day," Genesis 3:8).
The switch to bipedalism
and new habitat necessitated the banding of hominids into cooperative groups and increased selective pressure on learning and imitation, leading to changes in the hormonal balance of the sympathoadrenal system, increased period of post-natal development, and growing hemispheric specialization.
In Finding Our Tongues: Mothers, Infants, and the Origins of Language, Dean Falk contends that the evolution of bipedalism
(upright walking on two legs) and concomitant changes in infant development favored enhanced mother-infant vocal communication, which eventually led to human language, music, and art.
Of the many phenotypic traits that define our species--notably the physically and metabolically enormous brain, advanced cognitive abilities, complex vocal organs, bipedalism
and opposable thumbs--most (if not all) are the product of strong positive selection.
Looking at such criteria as bipedalism
, tool-making, and symbolic thought, Tattersall leads the reader through a philosophical as well as a paleoanthropological journey.
(31) Intergroup conflict was exacerbated by bipedalism
and upright walking, which allowed our ancestors to forage over a larger range, supporting the formation of bigger groups.
The pattern of human evolution: studies on bipedalism
, mastication and encephalization.