Question

Habitual bipedalism in hominids/humans arose initially through?

Answer 1

Bipedalism was much developed before large human brain or stone tool development. Bipedal specializations are seen in Australopithecus fossils present about 4.2-3.9 million years ago, Sahelanthropus might have Bipedalism as early as seven million years ago. Habitual bipedalism was a major adaptation that separated hominids from rest of the apes. Hominid bipedalism evolved as a result of natural selection about 5 million years ago

There is a hypothesis that bipedalism developed in humans because of differentially successful survival by carrying food to share it with their group family but other hypotheses also exists. Injured bonobos and chimpanzees were able of sustained bipedalism.

In Humans bipedalism is based Darwinian principle of natural selection. Hominins did not become bipedal consciously but eons allowed evolution of habitual bipedalism in hominids as it was a favorable. A distinctive set of traits in all species constitute characteristics that have lasted through natural selection out of the countless mutation traits that were observed during the timeline of the species.

In the Triassic period some groups of archosaurs developed bipedalism. In dinosaurs all early forms and many later groups were habitual or exclusive bipeds.Birds are members of a clade of exclusively bipedal dinosaurs, the theropods. According to the warning display model bipedalism element of the strategy of general of early hominids based on aposematism and intimidation of predators and competition using exaggerated visual and audio signals.

Threat displays might have been transitional behaviour that led to some apes beginning to adopt bipedal postures more often.According to Dart (1925 )the need for more vigilance against predators could have provided the initial motivation. Dawkins believed it could have started as a kind of fashion that just caught on and then escalated through sexual selection. Tanner in 1981 suggested that male phallic display could have been the initial incentive as well as increased sexual signaling in upright female posture.