Question

Could you go over this assignment please??

The Hominins

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.

Before you begin make sure view all relevant reading material so that you can give me informed opinions.

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.  

Answer 1

The locomotion strategy of Ardipithecus ramidus and Australopithecus afarensis are different from each other in many ways. The Ardipithecus ramidus were bipedal according to the fossil records and unlike the previous hominins, it had a big toe that helped it in better grasping and hence better locomotion and climbing abilities across the trees. They exhibited bipedalism. According to the fossil records, their foot was suitable for walking on wide range of environment like woodland, grassland and swamps. Their feet were suited for both climbing as well as walking and this was one of the biggest evolutionary changes from previous hominin groups. With their big toe or hallux they were better adapted towards locomotion of trees.

When it comes to the Australopithecus afrarensis, it is one of the oldest fossils that has been documented for the first bipedalism. They had long and very strong arms along with fingers that were curved for better grasping and this strengthened their locomotion on the trees. They were able to climb the trees efficiently with help of their legs and arms. They had a short stature but they had an adaptation that enabled them to live both on trees as well as ground. There is a lot of debate regarding its locomotion as some records state it was bipedal and some states it was arboreal. They has curved finger and toe bones known as phalages that helped them with better grasping and was better adapted for climbing. They had pelvis that resembles modern day humans with short and wide iliac blades. They had adducted big toes and this is one of the significant things that shows that it was bipedal.

According to all the study and research, it is considered that the Australopithecus afraensis is the one which was the first bipedal. It marked a symbolic evolutionary transition where the locomotion features were evolved for bipedalism.