100 Best Books for an Education

A Revision and Update of Will Durant's 100 Best Books for an Education

 

Appendix 8

 

Evolution and the Human Family Tree

 

With the turn of the 21st century, the pace of increasing fossil discoveries extended our familiarity of human origins into the very remote past. Though debate continues amongst paleoanthropologists about the implications of particular fossil finds, novel tools (e.g. DNA analysis), offer scientists an additional insight into primate evolution. Many signs presently indicate that the original primate arose approximately 85 million years ago, well prior to the first fossil thus far recognized as a primate. As with almost everything relating to human evolution, the original scenes, and even into the comparatively recent past, took place on the African continent.

 

Table of Human Evolution

 

Age

Species

Where

Discovered

Comments

c. 40 million years ago

Catopithecus

Egypt

To most anthropologists, Catopithecus represents the primeval ancestor of the higher primates.

c. 35 million years ago

Aegyptopithecus

Egypt

A petite, simian-like, fruit-eating animal roughly the size of a domestic cat, Aegyptopithecus is occasionally called the “dawn ape” and could be the most primitive commonly acknowledged ancestor of the hominoids.

c. 20 to 15 million years ago

Afropithecus

East Africa

Many different early apes inhabited Africa and Asia around this time. Experts hold two views on whether Proconsul or Afropithecus became the ancestor of the hominids—probably it was the latter; other apes at this time became the ancestors of gorillas and orangutans.

c. 7 to 6  million years ago

Sahelanthropus tchadensis

Chad

This is the most primitive known hominid, blending a flat human-like face with a brain the volume of a chimpanzee’s. It inhabited a diverse region of woodland and savanna close to what is today Lake Chad.

c. 6 million years ago

Orrorin tugenensis

Kenya (Tugen Hills)

Twelve fossils, incorporating pieces of limb bone and jawbones in addition to a few teeth, were unearthed in 2000. The name denotes “original man of Tugen,” for the discoverers’ contention that this is the ancestor of the human line. Various paleoanthropologists argue this assertion, even though all concede that Orrorin is a hominid.

c. 5.6 million year ago

Ardipithecus kadabba

Ethiopia (Middle Awash River Valley)

Publicized in 2001, these fossils incorporate a jawbone with teeth, hand and foot bones, and pieces of other bones. The discoverers categorize this as a subspecies of Ardipithecus, but are not certain whether Ardipithecus is an ancestor of australopithecines and humans or to chimpanzees. We shall assume the former.

c. 4.4 million years ago

Ardipithecus ramidus

Ethiopia

Unearthed in 1994 at Aramis, Ethiopia, A. ramidus inhabited an environment of woodlands combined with areas of savanna, rather than the genuine savanna theorized before this time to have been the habitat of human ancestors.

c. 4.2 to 3.9 million years ago

Australopithecus anamensis

Northern Kenya (Lake Turkana region)

The fossils discovered here definitely indicate that A. anamensis could walk erect on two legs, though bipedalism probably originated with either Sahelanthropus tchadensis or Orrorin tugenensis.

c. 3.6 to 2.9 million years ago

Australopithecus afarensis

Ethiopia and East Africa

Aka “Lucy” and “The Original Family,” almost all scientists believe that A. afarensis is on the direct line to modern humans. A track of footprints left in volcanic ash at Laetoli, Tanzania by A. afarensis displays that it too walked erect as distinct from any of the great apes.

c. 3.5 to 3.3 million years ago

Kenyapithecus platyops

Kenya

A skull recovered in 2001 was acknowledged as a new genus. M. G. Leakey reasons that a number of fossils formerly believed to be Homo rudolfensis could belong to the Kenyapithecus genus. This species may have been the most primitive tool user.

c. 3 to 2 million years ago

Australopithecus africanus

South Africa

This was the first nonhuman hominid to be unearthed in 1924, even so few anthropologists believed it until the 1950s. It walked erect and, though large brained for a primate, it had a brain that was much smaller than the first Homo species. It is currently understood to be on the direct line to Homo.

c. 2.5 to 1.5 million years ago

Homo habilis

 

Kenya, Tanzania, and South Africa—possibly Central Eurasia (Georgia)

The most primitive known species of our own genus, H. habilis (“Handy Man”) was named for tools recovered close to their fossil sites, even though the australopithecines, whose coeval fossils are also recovered nearby, almost certainly made tools. H. rudolfensis, which had larger brains and teeth, are currently believed to be the male of the habilis species. It is highly likely that what differentiated Homo from his predecessors was the, though rudimentary at first, ability to speak.*

c. 1.8 million to 40,000 years ago

Homo erectus

 

Africa, Asia, and Europe

Aka “Java Man” and “Peking Man” H. erectus (“Upright Man”) was a thriving maker of hand axes and exploiter of fire that many have thought to be the direct ancestor of H. sapiens; the last groups of H. erectus were coeval to the earliest members of H. sapiens. This species is also known as H. ergaster (“Work Man”) and its fossils were recovered in the Republic of Georgia.

c. 600,000 to 120,000 years ago

Homo heidelbergensis

Europe and North Africa

This group, possibly those in Spain or North Africa whom scientists occasionally call Homo antecessor, look to be the ancestors of the Neanderthals.

c. 200,000  to 30,000 years ago

Homo neanderthalensis

Europe and the Near East

This species flourished in the Ice Age, but became extinct soon after H. sapiens proliferated across Europe. Although DNA studies indicate that H. neanderthalensis and H. sapiens are diverse species, a few fossils have a combination of characteristics that most scientists believe indicates inter-species breeding. The DNA analysis verifies this conclusion.

c. 150,000 years ago to present

Homo sapiens

Worldwide

The first H. sapiens, occasionally called “archaic,” inhabited Africa and probably evolved from H. erectus. DNA evidence implies that roughly 100,000 years ago they proliferated into Asia and Europe. By 30,000 years ago, they were the sole remaining hominid.

    Roughly 35,000 years ago, the pace of cultural change began to hasten rapidly. Scientists refer to this epoch as the late Stone Age, or in Europe, the Upper Paleolithic. The most renowned type of human beings from this time are the Cro-Magnons aka Homo sapiens sapiens. The Cro-Magnons inhabited Europe from roughly 35,000 to 10,000 years ago. Scientists speculate that their appearance was similar to modern Europeans. Advanced toolmaking was a key achievement of the Cro-Magnons and other late Stone Age peoples. In addition, the emergence of art was one of the most impressive events of the late Stone Age. Moreover, a number of anthropologists argue that human beings could have originally begun to speak sometime during the late Stone Age. These scientists think that the many cultural events that appeared at this time—particularly the emergence of art—could be connected to the evolution of speech.* The early stages of modern speech, the establishment of artwork, and the creation of complex tools all compelled improvements in human intelligence and collaboration.

 



* “My own view,” writes Michael Corballis “is that language developed much more gradually, starting with the gestures of apes, then gathering momentum as the bipedal hominids evolved. The appearance of the larger-brained genus Homo some 2 million years ago may have signaled the emergence and later development of syntax, with vocalizations providing a mounting refrain. What may have distinguished Homo sapiens was the final switch from a mixture of gestural and vocal communication to an autonomous vocal language, embellished by gesture but not dependent on it.” Corballis, M.C., From Hand to Mouth: The Origins of Language, Princeton: Princeton University Press, 2002, 183.

* Will Durant’s hypothesis about the origins of thought and the creation of the “common noun” is probably the best description of what happened to humans in the late Stone Age cultural explosion. It wasn’t the birth of speech per se, but the adoption of this major improvement that set off these developments.