1) How does Homo habilis compare to A. africanus and P. boisei? Describe the general similarities and differences.

How does Homo habilis compare to A. africans and P. boisei? Describe the general similarities and differences.

A:

Homo habilis was a hominid that existed between 2.4 million and 1.6 million years ago, coinciding in part of these years with Homo erectus and Homo rudolfensis. It lived especially on the African continent, being there where the first fossil remains were found that proved its existence.

His name as "habilis" comes from the word "skillful" and is due to the fact that it is believed that he was capable of creating lithic instruments, possessing the ability to make stone instruments and also to manipulate certain objects.

The main physical characteristics of Homo habilis are the following:

-Skull more rounded than that of the previous species.

-Face less prognathic than australopithecines.

-Incisors larger than Australopithecus africanus which were small.

-Spadiform incisors (sword-shaped, pointed). That allowed them to cut and tear the meat easily.

-Large and thick enamel molars.

-The incisors of Homo habilis did not have a diastema, that is, the small gap that exists between two teeth, similar to its ancestor A. africanus.

-The foramen magnum (occipital hollow) is located more towards the center.

-The face was flat or short, similar to Australopithecus africanus, but more so than in previous Australopithecus species.

-Curved fingers of feet and hands, which indicated that they still used the trees, similar to Australopithecus.

The bipedal position in females causes a reduction of the pelvis that has as a consequence an earlier parturition (which implies prematurity of the neonate, a longer time dedicated to rearing and thus the need to maintain strong social ties that potentially contribute to development of a culture).

-The cranial capacity was greater than in other species approximately 600 cm³, relatively larger than in A. africanus.

-His height was somewhat under five feet tall, weighing just over 50 kilos in the case of men. In women the normal height was one meter, and the weight was little more than 30 kilos.

Analyzing some of the recovered bone remains, it can be recognized that it is a species with a much more human aspect than that found in australopithecines. The head of the femur is larger, shorter and more rounded. Also the pelvis has a more modern look.

Its height was similar to that of Australopithecus africanus, about 1.3 m and an average weight of 52 kg for males and 32 kg for females.

Australopithecus are a genus of hominid and extinct primates that inhabited Africa for a long time. Its transit through the world was between 3.9 million years ago until 2 million years ago, occupying the eastern and southern parts of the African continent.

-A. Africanus is characterized by a larger skull with more brain power.

-In general, it had a more globular skull than previous Australopithecus species and a broad forehead.

 -A face and teeth with a less primitive appearance than that of A. afarensis. For this reason, some scientists believe that the southern species of the primitive Australopithecine could be an ancestor of the genus Homo.

-Walks in a bipedal way although they had arboreal activity.

-Its average weight ranged from 33 kg to 67 kg with a height of 1.50 m tall.

-Its cranial capacity is from 480 cc to 520 cc. The cranial box is taller and more rounded than that of anthropomorphs.

-The face is shorter and has less prognathism and a smaller size of teeth than in other ancestor species. Their teeth do not differ much from today's man.

-The canines were small, without protruding as in the anthropomorphic and the incisors are as small as ours.

-The diastema (separation between incisors) disappears, or its existence is very rare.

According to other scientists, however, certain facial and cranial features denoting a strong complexion identify it as an ancestor of the robust australopithecines that later lived in the same region.

Paranthropus boisei is an extinct hominin species from East Africa. Fossils appear in the fossil record from 2 million to one million years ago.

The species was assigned to the genus Paranthropus by Robinson in 1960, and later to the genus Australopithecus by Leakey et al. in 1964, however, Robinson's ascription prevailed.

-His cranial capacity was around 515 cm³. Similar to A. africanus.

-The broad and rounded face.

-Very small incisors, similar to Australopithecus, but huge molars four times larger than in Homos sapiens.

-It had a sagittal crest to which large chewing muscles had to join.

-Its foramen magnum is more advanced than in Australopithecus (as in the genus Homo).

- Otherwise, the weight, height and general appearance is very similar to the other Australopithecus.

Paranthropus boisei lived in a drier environment than its Australopithecus ancestors. Faced with climate change, the species of this genus resorted to the specialization of their chewing apparatus in order to survive in a drier environment. Thus, with powerful jaws, he was able to access roots, thick stems, etc. In contrast, the rest of its body structure did not vary practically at all with respect to its Australopithecus ancestors.

Paranthropus, with some resemblance to gorillas, shared its habitat with three other hominins: Homo habilis, Homo rudolfensis, and Homo erectus. Unlike these, P. boisei had a more herbivorous diet, while the others were more opportunistic: they ate meat and protein foods that allowed them to develop more intelligence and led to a greater use of tools. However, P. boisei also ate termites and ants, as do modern apes.