Question

1. Explain what scientists have discovered regarding the major adaptations associated with each of the following transformational stages or "steps" in our evolutionary history. (refer to lecture and video notes, course texts, handouts, "Your Inner Fish" video series, and onlikine resources to complete this assignment.)

Please write each answer with long sentences

- Earliest Hominins (from the Late Miocene and Early Pliocene, ex. Sahelanthropus tchandensis, Ardipithecus ramidus)

- Early hominins of the Australopithecus group (ex. Australopithecus afarensis, Kenyanthropus platyops, Au. garhi, Au. africanus, Au. sediba, Paranthropus robustus, Paranthropus boisei)

- Earliest member sof the genus Homo (ex. Homo habilis, Homo rudolfensis)

- Early hunting and gathering hominins (ex. Homo ergaster, Homo erectus)

- Hunting and gathering hominins that controlled fire (ex. Homo heidelbergensis)

Thank you

Answer 1

Major adaptations in Earliest Hominins

It is found that the chimpanzees share the closest evolutionary history with humans being the closest ancestors. The earliest hominins lacked some of the features that gradually evolved in later hominins. They had lot of features that made them close to humans and the major adaptations were reduction in canine size, the C/P3 honing complex was absent, morphological adaptations for bipedality with help of the hindlimb and pelvis. The signs of earliest hominins being the earliest form of humans are their bipedality. In the fossil of the Ardipithecus, it was found that they had mandibular fragments which isolated the teeth and post cranial elements.

Early Hominins of Australopithecus group

The Australopithecus were one of the earliest hominins who had bipedal characteristics along with large chewing teeth. They had a brain size that is larger than the ancestor apes. They had human like canine tooth, large molars and short face. They were able to stand upright and the head was placed right above their vertebral column. They lost most of the climbing features, had short and broad pelvis and were able to balance on two limbs.

Earliest members of genus Homo

These species gradually evolved and one of the major differences was they had larger braincase, smaller face and teeth as compared to early hominin. They had long arms. Their tooth enamel was strong and hence they still could chew hard food. Most of the scientists even think that they were the first Homo to make the first stone tool.

Adaptations of early hunting and gathering hominins

The homo erectus are the first hominins known for hunting and using slightly sophisticated tools and fire. They were the first upright humans and they were mostly divided into Homo erectus and Homo ergaster. They had similar anatomy like of a modern man. They had long legs that helped them run faster. They had bodies with little hair that helped in evaporation and cooling. They had strong neck muscles with shallow forehead, sloping back and a bony brow ridge. The brain case was slightly elongated with narrow frontal and temporal lobes.

Adaptations of hunting and gathering hominins that controlled fire

They were the first one to have full control on use of the fire and more evolved as compared to their ancestors. They had large brow ridge and were the oldest to control fire and use of wooden spears, They had a larger braincase along with a flat face. They had a nearly complete mandible but only the premolar and first two molars on left were missing. They are able to control the fire by building proper fireplace with help of tools and burnt wood.