Beginning in the late Miocene and into the early Pliocene, upright walking tendencies began to develop
among the hominin tribe. Upright walking tendencies slowly transformed into obligate bipedalism during
the pliocene within the hominin lineage. This shift in locomotor strategy is notably marked by the gradual
change in arm to leg ratio that we see when comparing early and later hominins. Early hominins have
short legs and very long arms while later hominins have longer legs and short arms.
Your task for this activity will be to compare and contrast the locomotor strategies of the following two
hominin species: Ardipithecus ramidus and Australopithecus afarensis. You will accomplish this by
answering the following questions.
Which hominin had the best arboreal capabilities (look at both upper and lower extremities)? Make sure
you explain your answer and give me at least one features that backup your claim. The feature that you
choose has to be from lower extremities.
Which hominins was the first to not just be an upright walker but an obligate biped (this means you have no
choice but to walk on two legs)? Make sure you explain your answer using the same feature that you used
when looking at the other hominin for comparative purposes.
Lastly, I would like you to give a short summary of the notable transformations in locomotor strategy that
occur over time as seen from Ardipithecus ramidus to Australopithecus afarensis.
Which hominin had the best arboreal capabilities (look at both upper and lower extremities)? Make sure
you explain your answer and give me at least one features that backup your claim. The feature that you
choose has to be from lower extremities.
Which hominins was the first to not just be an upright walker but an obligate biped (this means you have no
choice but to walk on two legs)? Make sure you explain your answer using the same feature that you used
when looking at the other hominin for comparative purposes.
Lastly, I would like you to give a short summary of the notable transformations in locomotor strategy that
occur over time as seen from Ardipithecus ramidus to Australopithecus afarensis.
Sample Solution