Question

Which was the first hominin to be considered an obligate biped?

1) Australopithecus afarensis
2) Ardipithecus ramidus
3) Sahelanthropus tchadensis
4) Homo sapiens

Answer 1

The first hominin species to be considered an obligate biped is Australopithecus afarensis, as evidenced by the Laetoli footprints which showed a bipedal gait.

Step-by-step explanation:

The first hominin species considered to be an obligate biped is Australopithecus afarensis. Evidence of their obligate bipedalism comes from the Laetoli footprints, discovered by Mary Leakey, which revealed a modern striding gait indicative of bipedal locomotion. These footprints, dated to about 3.5 million years ago, provide the earliest clear evidence for humanlike bipedalism well before the appearance of the genus Homo. Although Ardipithecus ramidus was bipedal and is dated earlier to about 4.4 MYA, its bipedality was less obligate, with some adaptations still suited for life in the trees.

Australopithecus afarensis walked upright consistently, key in the transition from tree-dwelling to a terrestrial lifestyle and in the evolutionary path towards genus Homo, which includes modern humans. This fundamental change in locomotion represents a significant evolutionary step and highlights the adaptive nature of hominins in response to their changing environment.

Answer 2

The first hominin species to be considered an obligate biped is Australopithecus afarensis, as evidenced by the Laetoli footprints which showed a bipedal gait.

Step-by-step explanation:

The first hominin species considered to be an obligate biped is Australopithecus afarensis. Evidence of their obligate bipedalism comes from the Laetoli footprints, discovered by Mary Leakey, which revealed a modern striding gait indicative of bipedal locomotion. These footprints, dated to about 3.5 million years ago, provide the earliest clear evidence for humanlike bipedalism well before the appearance of the genus Homo. Although Ardipithecus ramidus was bipedal and is dated earlier to about 4.4 MYA, its bipedality was less obligate, with some adaptations still suited for life in the trees.

Australopithecus afarensis walked upright consistently, key in the transition from tree-dwelling to a terrestrial lifestyle and in the evolutionary path towards genus Homo, which includes modern humans. This fundamental change in locomotion represents a significant evolutionary step and highlights the adaptive nature of hominins in response to their changing environment.