In an article on the discovery, published in the journal Nature, Dart wrote: For the production of man a different apprenticeship was needed to sharpen the wits and quicken the higher manifestations of intellect—a more open veldt country where competition was keener between swiftness and stealth, and where adroitness of thinking and movement played a preponderating role in the preservation of the species.
In the decades following Dart's discovery, more hominid fossils were found in Eastern and Southern Africa, leading researchers to conclude that these were savanna dwellers as well.
Much of the academic discussion at the time took for granted that the transition to the savannas was responsible for the emergence of bipedalism, and focused instead on determining particular mechanisms by which this happened.
[13] Paleoanthropologists also posited that the upright posture would have been advantageous to savanna-dwelling hominids, as it allowed them to peer over tall grasses for predators, or in search of prey.
[14] P. E. Wheeler suggested that another advantage lay in reducing the amount of skin exposed to the sun, which helped regulate body temperatures.
[16] Monod investigated the role in human evolution of the Sahara during wet periods as a place that was covered with steppes, savannas, and lakes.
[17] In analogy with gelada Jolly proposed that "[i]n the basal hominid, therefore, the 'gelada' specialisations would be superimposed upon a behavioural repertoire and post-cranial structure already attuned to some degree of truncal erectness."
He stated "[i]t is more likely that hominids venturing into open habitats were already bipedal and that their regular occupation of savannahs was not possible until intensified social behavior was well developed.
According to him, the Great Rift Valley, the Nile and the Zambezi acted as a double barrier when a period of desiccation occurred in East Africa.
"[20] This corresponded with the location of some important fossils that had been found until then, such as in 1939 the Australopithecus afarensis in Laetoli by Ludwig Kohl-Larsen and the Paranthropus boisei in the Olduvai Gorge in 1959 by Mary Leakey.
"[26] For Phillip Tobias, the 1994 find of Little Foot, the collection of Australopithecus africanus foot bones demonstrating features consistent with tree-climbing as well as an upright gait, contributed to calling the savannah hypothesis obsolete, stating Open the window and throw out the savannah hypothesis; it's dead and we need a new paradigm.
Based on animal finds in the vicinity, this suggests a mosaic of environments from gallery forest at the edge of a lake area to a dominance of large savannah and grassland, although more research was needed to determine this precisely.
Thure E. Cerling developed a method to determine the forest cover of ancient landscapes, thus no longer requiring a definition of what a savannah is.
By distinguishing between the C3 plants of the tropical forests and the mix of trees and C4 grasses of the savannah, they investigated the stable carbon isotope of paleosols from some sites in East Africa.
According to Domínguez-Rodrigo, the savannah hypothesis can still give a good explanation, although the transition of environment has probably been less abrupt than some earlier authors thought.