Question

Hominin taxonomy and way of life. Hominins are characterized most notably by habitual bipedalism - but of course there are a lot of differences among hominins too. Now you get to talk about things like brain size, jaws and teeth, skull features, height, hands, etc. Each genus of hominins has its own characteristics, time and habitat, diet and behaviors. Your job is to describe them and discuss the probable evolutionary relationship between the groups.

1. What do we know about genus Ardipithecus? Describe some notable anatomical characteristics, the time range and habitat in which members of this genus lived, diet and behaviors.
2. What do we know about genus Australopithecus? Describe some notable anatomical characteristics, the time range and habitat in which members of this genus lived, diet and behaviors.
3. What do we know about genus Paranthropus (your book refers to members of this genus as robust Australopithecines)? Describe some notable anatomical characteristics, the time range and habitat in which members of this genus lived, diet and behaviors.
4. What do we know about early genus Homo (e.g. Homo habilis and early Homo erectus)? Describe some notable anatomical characteristics, the time range and habitat in which members of this genus lived, diet and behaviors. What anatomical and behavioral characteristics differentiate Homo from other hominin groups?
5. Put these four genera (plural of genus) in chronological order, and note any overlaps in time. According to anthropologists, which of the first three genera is/are probably ancestral to genus Homo? Which genus is not ancestral to Homo, but an ancient cousin?
6. Make sure to include in-text citations throughout, so I know which resources you are using.
7. DO NOT do internet searches to answer these questions. Use your text and my online lecture and the links included in it. The point is to read, study, think, answer the Week 4 study questions, review the material, and then draft your essay. If you try to take a short cut and google stuff, you will not understand the context of what you find.

Answer 1

Ans 1)

Ardipithecus is a genus of an extinct homininethat lived during the Late Miocene and Early Pliocene epochs in the Afar Depression, Ethiopia. They are originally described as one of the earliest ancestors of humans after they diverged from the chimpanzees. the fossil evidence from the Middle Awash indicates that both A. kadabba and A. ramidus lived in "a mosaic of woodland and grasslands with lakes, swamps and springs nearby," They lived About 4.4 million years ago. Ardipithecus ramidus individuals were most likely omnivores, which means they enjoyed more generalized diet of both plants, meat, and fruit. Ar. ramidus did not seem to eat hard, abrasive foods like nuts and tubers.

Ans 2)

The genus Australopithecusapparently evolved in eastern Africa around 4.2 million years ago. Based on strong and robust skulls, large mandibles, and thick enamel, some concluded that Au. afarensis ate hard and brittle foods. However, later studies found that while Au. afarensis could eat these foods, their diet actually consisted of softer foods, mainly grass, leaves, and fruits.

The Australopithecus species, referred to as Australopithecines, had features that were both human-like and ape-like. Their brains were smaller and more in the range of the brains of modern apes. They tended to have longer arms that seemed well-suited to climbing. In general, their facial features looked more ape-like than human, with sloping faces and jutting jaws.

However, their skeletons show that they walked upright. Furthermore, the teeth of some species were more like human teeth. Perhaps more importantly, they showed that our ancestors started walking upright before the evolution of larger brains.

Ans 3)

Paranthropus lived inEastern Africa (Ethiopia, Kenya, Tanzania, Malawi). They lived About 2.3 to 1.2 million years ago.

This species was nicknamed Nutcracker Man for its big teeth and strong chewing muscles, which attached to the large crest on the skull. Those features show that Paranthropus boiseilikely ate tough foods like roots and nuts. But dental microwear patterns seen on P. boiseiteeth are more similar to living fruit-eaters with fine striations, rather than large, deep pits seen in the teeth of living species that eat grass, tough leaves and stems, or other hard, brittle foods. While the morphology of P. boiseiskull and teeth indicate it could have chewed hard or tough foods, dental microwear analysis does not demonstrate that they regularly did so, suggesting a wider, more diverse diet for P. boisei. It's possible that this species only ate hard or tough foods during times when its preferred resources were scarce, relying on them as fallback foods.

This species lived in environments that were dominated by grasslands but also included more closed, wet habitats associated with rivers and lakes.

Ans 4)

Homo habilis are generally called handy man and were found  Eastern and Southern Africa about 2.4 million to 1.4 million years ago. This species, one of the earliest members of the genus Homo, has a slightly larger braincase and smaller face and teeth than in Australopithecus or older hominin species. But it still retains some ape-like features, including long arms and a moderately-prognathic face.  Early Homo had smaller teeth than Australopithecus, but their tooth enamel was still thick and their jaws were still strong, indicating their teeth were still adapted chewing some hard foods (possibly only seasonally when their preferred foods became less available). Dental microwear studies suggest that the diet of H. habilis was flexible and versatile and that they were capable of eating a broad range of foods, including some tougher foods like leaves, woody plants, and some animal tissues, but that they did not routinely consume or specialize in eating hard foods like brittle nuts or seeds, dried meat, or very hard tubers.

Homo erectus lived in Northern, Eastern, and Southern Africa; Western Asia (Dmanisi, Republic of Georgia); East Asia (China and Indonesia). They were found Between about 1.89 million and 110,000 years ago. Early African Homo erectus fossils (sometimes called Homo ergaster) are the oldest known early humans to have possessed modern human-like body proportions with relatively elongated legs and shorter. The appearance of Homo erectus in the fossil record is often associated with the earliest handaxes, the first major innovation in stone tool technology.

The tall bodies and large brains of Homo erectus individuals required a lot of energy on a regular basis to function. Eating meat and other types of protein that could be quickly digested made it possible to absorb nutrients with a shorter digestive tract, making more energy available faster. There is also speculation that honey and underground tubers may have been significant food sources for Homo erectus.

Ans 5)

Arrangement of these genera in chronological order:

Ardipithecus

Australopithecus

Paranthapus

Homo habilis

Homo erectus

And the closest generas to Homo sapiens are:

Homo erectus, Homo habilis and Paranthapus.