Chapter 11 - ANTH 2200 - The Origins and Evolution of Early Homo

Homo floresiensis

Dubbed the "hobbit" for its diminutive size, a possible new species of Homo found in Liang Bua Cave on the Indonesian island of Flores. Considering the trend in hominin evolution toward larger bodies, finding such a small hominin so recent in history was surprising. It is possible that Homo floresiensis's size was due to living on a small island with limited resources, however, this has not been definitively determined. In contrast to contemporary hominins, Homo floresiensis likely had a very small brain. The Flores fossils date from 700,000 yBP to 60,000 yBP. This is remarkable considering the proliferation of Homo erectus at that time.

Dmanisi hominins

Had much smaller faces, jaws, and brains than other Homo erectus finds, with a cranial capacity ranging from about 550 cc to 650 cc. These hominins resemble other Homo erectus finds in the shape, not size, of their features.

Rising Star Cave

Homo naledi is a new species of the genus Homo that is similar to Homo erectus yet contains unique-enough characteristics to warrant a separate species. This hominin was first discovered at the South African site Rising Star Cave in 2013. The members of the excavation team had to crawl through narrow tunnels in order to access the fossil site. Once there, they had to work in the dark, claustrophobic space for up to six hours at a time. The fossils from Rising Star Cave have been dated to 335,000-236,000 yBP. Archaeologists at Rising Star Cave have uncovered 1,550 hominin fossils representing at least 15 individuals. The fossils represent one of the largest collections of early hominins found at one site anywhere in the world. Paleoanthropologist Lee Berger and his team found and described at least 15 hominin individuals that are thought to have been intentionally placed by members of the same species.

Why is the date 1.8 mya so important in hominin evolutionary history?

It was the time Homo erectus appeared in both Africa and Asia.

Homo habilis

The earliest Homo species, a possible descendant of Au. garhi and an ancestor to H. erectus; showed the first substantial increase in brain size and was the first species definitively associated with the production and use of stone tools. The first hominin to have anatomical and behavioral characteristics that foreshadowed the evolution of Homo sapiens: greater intelligence, reliance on tools, and dietary and behavioral flexibility. Lived 2.5-1.8 mya.

cooking hypothesis

The hypothesis that cooking food increases the efficiency of digestion and availability of nutrients required for brain and body growth and development, thus explaining the increase in brain and body size in H. erectus relative to earlier hominins.

handaxe

The most dominant tool in the Acheulean Complex, characterized by a sharp edge for both cutting and scraping.

Pithecanthropus erectus

The name used by Eugène Dubois for his first fossil discovery, which later became known as Homo erectus. Nicknamed "Java man," it had a cranial capacity of 1,000 cc. This was a key characteristic that clearly set the fossil apart from both modern apes (400 cc) and humans (1,450 cc). Most early fossil finds, including this one, were met with skepticism. This is especially true of those fossils that were not found in Europe, as early researchers incorrectly believed that everything important in human evolution happened in Europe.

Acheulean Complex

The stone tool culture associated with H. erectus; characterized by the use of handaxes and other types of stone tools. It was more refined than the earlier Oldowan Complex.

Although he did not directly study human fossils, ______________ first postulated that humans evolved from African apes, while his contemporary, biologist _______________, first suggested that humans evolved from Asian apes. a. Tim White b. Charles Darwin c. Eugene Dubois d. Ernst Haeckel

b;d Although he did not directly study human fossils, Charles Darwin first postulated that humans evolved from African apes, while his contemporary, biologist Ernst Haeckel, first suggested that humans evolved from Asian apes.

What are the three characteristics the author uses to define the genus Homo?

1. relatively large brain 2. small face and jaws 3. dependence on material culture for survival

Turkana Boy

A Homo erectus fossil skeleton Discovered by Alan Walker, Richard Leakey, and colleagues at Koobi Fora Africa. This juvenile specimen had a cranial capacity of 900 cc. This fossil is also called "Turkana boy" for the area in which it was found. He would have grown to be over six feet tall, a huge increase over the height of Homo habilis

Homo naledi

A morphologically primitive hominin found in the later Pleistocene from cave deposits in South Africa. The general morphology of the hominin fossils from Rising Star Cave is representative of early Homo, but specific details in the bones and teeth reveal a mixture of both primitive and derived characteristics. The skull is similar to Homo erectus in overall shape, such as the presence of a sagittal keel, a large browridge, thick cranial bones, and reduced tooth size. Some authorities suggest the cranial morphology indicates that the hominin is a variant of H. erectus. However, H. naledi has a number of distinctive characteristics, including primitive, australopithecine-like morphology. For example, the estimated brain size for H. naledi is quite small—only 560 cc for males and 475 cc for females. In addition, similar to australopithecines, the hand phalanges are curved, the femur neck is long, and the body size and brain size are smaller than those of most other Pleistocene hominins. Given the presence of a number of primitive characteristics, many paleoanthropologists predicted early dates for these hominins, perhaps even in the range of Australopithecus or H. erectus. However, the fossils were dated to a relatively recent range of 335,000-236,000 yBP, setting the hominins from Rising Star somewhat late in time, far later than many paleoanthropologists would have predicted.

sagittal keel

A slight ridge of bone found along the midline sagittal suture of the cranium, which is typically found on H. erectus skulls.

Homo erectus

An early species of Homo and the likely descendant of H. habilis; the first hominin species to move out of Africa into Asia and Europe. Lived 1.8 million to 50,000 years ago.