Early Hominids:

·  The earth is estimated to be 4 billion to 5 billion years old.

·  Living beings are said to have appeared approximately 3.5 billion years ago.

·  Sometime around 3 million to 4 million years ago, the first hominid, or humanlike, creatures appeared.

·  These hominids were part of the zoological order called primates: mammals that developed about 65 million years ago and include apes, monkeys, and other related animals.

·  The earliest hominids (known as australopithecines) emerged in southern and eastern Africa 3 to 4 million years ago.

·  Many of the oldest hominid fossils were found in the 1950s and 1960s in the Great Rift Valley and Olduvai Gorge by Mary and Louis Leakey.

·  Their son Richard added to their paleontological discoveries in the 1970s, as did Donald Johanson, who uncovered the famous australopithecine fossil nicknamed “Lucy” in 1974.

·  Three features made australopithecines and their later descendants more advanced than earlier primates: bipedalism (the ability to walk upright), a sizable brain (which enabled abstract thought and fine motor control over the hand and tongue), and a larynx, or voice box, that allowed for complex speech (leading to the development of language).

·  Between 2 million and 3 million years ago, humanity’s immediate predecessors, the early members of the genus Homo, were born, also in Africa.

·  First was Homo habilis, or “handy human.”

·  Homo habilis had a larger brain than the australopithecines and made use of crude stone tools.

·  About 1 million years ago, Homo habilis died out, but an even more sophisticated hominid, Homo erectus, or “upright human,” had already emerged, approximately 1.8 million years ago.

·  Like previous hominids, Homo erectus originated in southern and eastern Africa.

·  Homo erectus, however, became the first human species to spread throughout the entire continent of Africa.

·  Moreover, it was the first to migrate to other parts of the world.

·  Asian remains of Homo erectus (popularly known as “Peking Man” and “Java Man”) date back to 1.6 million to 1.8 million years ago, and fossils of Homo erectus between 500,000 and 700,000 years old have been found in northern China and Europe.

·  Homo erectus had a brain one third larger than Homo habilis, and the newer species manufactured stone axes and basic wooden tools.

·  They also clothed themselves in skins and furs.

·  Homo erectus survived and prospered for more than a million years, until at least 800,000 years ago, and almost certainly longer.

·  Precisely how and when Homo erectus faded away and true humans developed remains poorly understood.

·  The two species may have coexisted for a number of years.

True Humans:

·  At some point between 100,000 and 250,000 years ago, true humans (Homo sapiens, meaning “wise human”) appeared.

·  Most likely, as Homo erectus did, Homo sapiens emerged in Africa, then spread to other continents.

·  The earliest variant of Homo sapiens was the Neanderthal.

·  A more advanced form was the Cro-Magnon, appearing sometime between 60,000 and 100,000 years ago.

·  Both used advanced tools, wore clothing, and created semipermanent or permanent dwellings.

·  Both organized themselves into social groups.

·  Both spread from Africa to Europe and Asia.

·  How and when the Neanderthals and the Cro-Magnon died out, giving way to modern humans, remains uncertain, although it is thought that the Neanderthal died out approximately 30,000 years ago.

·  Also unknown is exactly how Neanderthals and Cro-Magnon interacted, if at all.

·  Finally, between 100,000 and 200,000 years ago, modern humanity (Homo sapiens sapiens) emerged.

·  To what degree Homo sapiens sapiens coexisted with Neanderthals or Cro-Magnon is unknown.

·  Most scientists believe that Homo sapiens sapiens, like all other hominids, emerged in Africa, then migrated outward.

·  This would imply that Africa is also the sources of many features of modern human behavior (complex social networks, economic strategies, personal adornment, and the use of symbols and rituals in daily life).

·  This theory is informally referred to as the “Out of Africa” thesis.

·  An opposing model, the multiregional thesis, proposes that modern humans appeared simultaneously throughout the world, descending from earlier hominid groups that had already left Africa.

·  However, this theory is held by a minority of scholars.

·  Homo sapiens sapiens continued the worldwide hominid movement, spreading to Australia, the Arctic, and the Americas, as well as Africa, Europe, and Asia.

·  No earlier than 20,000 to 30,000 years ago (and perhaps as recently as only 5,000 to 6,000 years ago), these migrations, along with the need to adapt to different climates and environments, gave rise to minor evolutionary modifications.

·  The most noticeable of these are skin color and racial type (African, Asian, and Caucasian).

·  In terms of human biology, however, these racial differences are minute, and the genetic structure of all modern humans is virtually identical.

·  One of the principal characteristics separating hominids from their immediate ancestors is tool use.

A Sort of a Song

By William Carlos Williams

Let the snake wait under
his weed
and the writing
be of words, slow and quick, sharp
to strike, quiet to wait,
sleepless.
-- through metaphor to reconcile
the people and the stones.
Compose. (No ideas
but in things) Invent!
Saxifrage is my flower that splits
the rocks.