A BRIEF HISTORY OF HUMAN TIME

SCIENTISTS EXPLORING HUMAN ORIGINS PICK A FEW BONES

The study of human evolution has been plagued by personal conflicts and
idiosyncrasies ever since Charles Darwin began his study of life aboard the HMS
Beagle. Discussing the search for human origins, Mark Twain noted that
"scientists have already cast much darkness on this subject, and if their
investigations continue, we shall soon know nothing at all." Of course,
researchers now know a great deal about human ancestors. But the arguments and
counterarguments between them go on. In fact, judging from newspaper reports,
it seems that the fields of evolutionary biology and paleoanthropology have been
host to professional battles and personal wrangles in spades.

To illustrate the monkey business that has often accompanied the search for
missing links, we have created a couple of time lines: a Discovery Line, to
depict important scientific discoveries about human origins, and an Inside Line,
to illustrate the behind-the-scenes footnotes to those discoveries. To help you
put it all in context, we also present a life line that illustrates a reasonable
timetable for how hominid species actually evolved. (When reading the life line,
you'll note some incongruities, but our numbers merely reflect the data of a
science still in the process of being unearthed.)

As you read through our charts, you'll probably realize that bigheadedness
afflicts the human species in more ways than one. After all, scientists don't
deserve all the heat. They belong to the same species as the rest of us, and
their behavior tends to reflect the apish and territorial--though thoroughly
conventional--view that success lies in displacing the competition.

18 MILLION YEARS AGO

Proconsul.

Apelike creature thought to be an early ancestor of humans.

3-4 MILLION YEARS AGO

Australopithecus afarensis. The oldest hominid species yet found, thought by
many to be ancestral to humans. Lucy is a prime example of A. afarensis.

2.2-3 MILLION YEARS AGO

Australopithecus africanus. This hominid resembled A. afarensis but had a
rounder, more humanlike head and was found mostly in Africa. (The Taung child
was one.)

2.4-2.6 MILLION YEARS AGO

Australopithecus robustus. A robust, ruggedly built hominid found in two South
African caves, Thought to be an evolutionary dead end.

1-1.9 YEARS AGO

Australopithecus boisei. Found in East Africa, this hominid resembled robustus
but was notably larger.

1.8-2.2 MILLION YEARS AGO

Homo habilis. The first species in the genus Homo, H. habilis, or handy man,
remains have been found in East Africa. Habilis appears to have lived around the
same time as the appearance of the first simple stone tools.

300,000-1.9 MILLION YEARS AGO

Homo erectus. A more evolved, bigger-brained version ofhabiIis, erectus lived
Earth for 1.6 million years. Erectus created advanced tools and also mastered
fire. (Examples of H. erectus include the Java man and the Peking man.)

225,000-500,000 YEARS AGO

Homo sapiens (archaic). These ancient human forms, which seem to have evolved
from erectus, began appearing in the fossil record around 500,000 years ago.

35,000-15O,000 YEARS AGO

Homo sapiens (Neanderthal). Neanderthal people constituted a particularly
rugged group living in Europe and the Middle East during the Ice Age. As
temperatures warmed, they disappeared.

PRESENT-100,000 YEARS AGO

Homo sapiens sapiens (modern humans). Anatomically modern humans with skeletons
like ours first appeared in the fossil record about 60,000 years ago.

DISCOVERY LINE

1830

Geologist Charles Lyell publishes the first volume of his monumental Principles
of Geology, which proves the earth is much more than 6,000 years old. This,
along with the fossil record, suggests there has been tremendous change among
plant and animal life.

1857

Neanderthal man, represented by only a few pieces of the skeleton, including a
skullcap and leg bones, is discovered in Germany's Neander Valley.

1860

Darwin gets everyone excited in his book The Origin of Species when he
suggests natural selection as the means by which evolution works, (Darwin
proposes that individuals vary randomly in nature. Those variants best
adapted to the environment thrive-and eventually prevail-through the creative
force of natural selection.)

1871

In The Descent of Man, Darwin suggests that Africa is the place to look for
missing links. The reason: The continent was "formerly inhabited by extinct
apes closely allied to the gorilla and chimpanzee," the two species closest to
humans.

1877

Dutch anatomist Eugene Dubois resigns from academe and announces that he will
return with the missing link. He sets out for Java, a large island in
Indonesia, and does indeed return with the first evidence of Homo erectus, or
upright man.

1912

A very large humanlike skull and a small apish jaw are discovered at Piltdown in
England. Researchers, including paleontologist A. Smith Woodward, suggest that
the Piltdown remains represent the oldest known link between humans and apes.

1922

Henry Fairfield Osborn of the American Museum of Natural History proclaims a
single tooth found in the Snake Creek fossil beds of Nebraska is evidence of
"the first anthropoid ape of America."

1925

Professor Raymond Dart studies a small apish skull called the Taung child, from
the Taung limestone quarry in South Africa. Dart names the new species
Australopithecus.

1947

Scottish paleontologist Robert Broom proves Raymond Dart right in his assertion
that australopithecines were hominids by finding more evidence in South Africa.

1948

Mary Leakey discovers the skull of Proconsul, now thought to be our oldest
ancestor, on Rusinga Island in Kenya's Lake Victoria.

1953

The Piltdown find, exposed as a hoax, turns out to be a relatively modern human
skull combined with an ape's jaw,

1959

Mary Leakey discovers a 1.75-million-year-old australopithecine skull at Olduvai
Gorge in Tanzania, moving the cradle of mankind from South Africa to East
Africa.

1972

The oldest, most complete skull of a large-brained ancestor is found near
Koobi-Fora in northern Kenya by a research team led by the Leakeys' son Richard.
Named 1470 (after its museum accession number), the skull is said to be 2.8
million years old. If the dating holds, the skull will confirm Louis Leakey's
theory that the large-brained genus Homo existed millions

1974

Paleontologist Donald Johanson and his team discover a range of fossils more
than 3 million years old near Hadar in Ethiopia. These fossils include Lucy and
a group dubbed the First Family.

1977

Mary Leakey and her team in Tanzania discover the oldest evidence of our
ancestors' upright gait, the Laetoli footprints, preserved by a layer of
volcanic ash. The footprints are said to be 3.7 million years old.

1978

Johanson declares that Lucy and the First Family are small-brained
australopithecines ancestral to modern humans.

1985

Anatomist Alan Walker discovers the Black Skull, so-called because of a
manganese patina, in Kenya. Everyone agrees the skull forces a new drawing of
our family tree, but there's no consensus on a single drawing.

1986

The theory of Eve, proposed by Allan Wilson, suggests a single point of origin
for all modern humans, descended from a female in Africa. Wilson and his team
based this finding on a study utilizing mitochondrial DNA as a marker to trace
human ancestry.

1990

Johanson and his team from Berkeley return to Hadar, where they find a large
upper jaw with part of the face.

1991

Richard Leakey, now less involved in fossil hunting, heads up the Kenya Wildlife
Service. He is renowned for saving Kenya's elephants from ivory poachers.

INSIDE LINE

1830

Charles Darwin sets out on the voyage of the Beagle, taking along Lyell's work.
Darwin is not the official naturalist onboard but is chosen as a companion tor
the captain, Robert Fitzroy. His ticket is his ability to afford the trip.

1857

A professor from Bonn named August Franz Mayer suggests the bones belonged to
a Mongolian Cossack traveling through Prussia after Napoleon's retreat.
According to Mayer, pain had caused the man to furrow his forehead, explaining
the bold brow ridges; as for the man's bowlegs, Mayer says,.. they can be traced
to a job as a cavalryman atop a horse.

1860

Darwin ventures to publish after more than two decades of fear that his ideas
would be viewed as heresy by his religious family and Victorian England as a
whole. The Church, after all, holds that humans have been created by God. He
goes to press only when Alfred Russel Wallace is about to scoop him with a
remarkably similar theory of natural selection.

1871

Due in part to chauvinism and racism, early investigators prefer to look for
missing links anywhere but Africa: England, France, Germany, Spain, Chi na, and
even North America.

1877

When critics refuse to agree with his assessment, Dubois limits their access for
further study, hiding the fossils beneath his dining room floor.

1912

British anatomist Arthur Keith, jealous that the remains have not been give to
him to study, challenges Woodward's reconstruction. Keith's good friend Elliot
Smith sides with the other man, ending the Keith-Smith friendship.

1922

More teeth are found at the site, and the "Nebraska man" is reclassified as an
extinct pig.

1925

Most paleontologists, including Arthur Keith and Louis Leakey, dismiss Taung as
an odd ape. Dart and the Taung child become the subject of vaudeville jokes.

1947

Broom, who likes to search for fossils in the nude, is called "about as honest
as a poker player" and is twice banned from his own research site.

1948

The Leakeys celebrate the discovery by conceiving their third son, Philip.

1953

The person who planted the hoax is never found.

1959

The discovery brings Louis and Mary Leakey fame and more fortune than they have
ever known; support from the National Geographic Society enables them, in
Louis's words, "to do more in two years at Olduvai than we have done in the
preceding thirty." Even though Mary makes the discovery, Louis takes the
spotlight, writing "Finding the World's Earliest Man" for National Geographic.

1972

The discovery inspires a reunion between Louis and Richard Leakey, who have not
gotten along for several years, (As a teenager, Richard vowed to do anything but
follow in his parents' footsteps.) A few days after this reunion, the elder
Leakey dies of a heart attack, Subsequently, a fierce controversy over the age
of the skull pits scientists from the Omo River expedition, led by F. Clark
Howell, against Leakey's team from Koobi-Fora. Richard Leakey exhibits a
"distinct coolness" toward his mother, Mary Leakey, when she is skeptical of the
older date; he is also accused of suppressing scientific data that do not
support his theory.

1977

Paleontologist Ron Clarke says that because of her poor eyesight, Leakey has
inadvertently carved an extra heel into a set of footprints during the
excavation, creating a third hominid where there should be only two.

1978

Johanson's claim challenges the Leakeys' theory that our 3-million-year-old
ancestors were a species of the genus Homo.

1981

Richard Leakey and Johanson appear in a U.S. television debate hosted by Walter
Cronkite. In front of a national audience, Leakey draws a big X across
Johanson's chart of the human family tree. It isn't the tree that irks Leakey
so much as Cronkite's prologue: "Before the discovery of Lucy made Donald
Johanson a celebrity, the king of the mountain in paleoanthropology was Richard
Leakey."

1985

Richard Leakey suggests that the skull proves there were actually two
australopithecine species at Hadar in Ethiopia. Johanson announces a consensus
among other colleagues that there was only one species.

1986

Fossil finders pursue a Bones versus Blood War against the molecular biologists.

1990

The bones now suggest there may have been two species at Hadar, not one.

1991

Richard's wife, Dr. Meave Leakey, is now head of paleontology at the Kenya
National Museum, where she oversees a team of accomplished fossil finders known
as the Hominid Gang.