It Ain't Necessarily So
Popular Theories About Human Origins Should Be Taken with a Pinch of
What does it mean to be human? What special features make us unique,
different from every other species on the planet? And when in our
evolutionary history did humanness first appear? We call ourselves Homo
sapiens sapiens, which lays claim to a large measure of wisdom for our
kind. But we have great trouble defining ourselves or discovering when
we emerged onto the world scene. We don't even know what to think of a
similar species like the Neanderthals, who shared that world with us for
a while before disappearing. Were they our ancestors? Or more like
cousins? Did we fight or compete them into extinction? Did something
else happen to them?
These questions increasingly occupy anthropologist Alan Mann.
He would like to find solid answers, but it's a frustratingly difficult
task. The problem isn't a lack of sapience among researchers; it's a
lack of evidence out in the field. Mann wants to understand "why we look
and behave the way we do today," but he admits that our ancestral line
left a pretty skimpy fossil record, compared to creatures like
dinosaurs. On the other hand, we did better than insects. In spite of
the popularization of the notion by Jurassic Park, not many of them got
caught in amber for future scientists to examine. But early primates
didn't leave all the splendid complete skeletons that tyrannosaurus rex
and other dinosaurs did. Anthropologists get very excited when they find
the rare primate skeleton, like that of Lucy. This little
australopithecine from eastern Africa was an adult (roughly 3 million
years old), small-brained but fully bipedal. She weighed about 60 pounds
and stood a little more than three feet tall.
Often, Mann says, we can't even tell the adult size of one of our
ancestral species. Bones rarely survived intact or as parts of complete
specimens; soft tissue left no trace at all. "We were extremely lucky
some years ago," he points out, "when Mary Leakey found a hominid
footprint trail in East Africa. She's often said how delighted she'd
have been if one of these creatures had been a total klutz, tripped over
its own feet, fallen flat in the volcanic ash, stood up, brushed itself
off, and left a soft tissue impression for us to find."
It didn't. And that's one reason Mann likes teeth. More of our early
ancestors' teeth have survived than anything else of theirs. Teeth are
also informative in ways that bones can't be. The shell of enamel
covering the crown of a tooth is the hardest part of an animal and one
of the few substances that preserves a record of its owner's
development. "Bone is a dynamic material. It's constantly being
remodeled. Certain cells break bone down; then new bone is deposited.
It's always being changed. But enamel is formed by cells that secrete an
organic matrix around which a mineral crystal is deposited. Once the
enamel is formed, it never changes. So enamel preserves a record of the
animal's growth and development, its youth, and any metabolic
disturbances it experienced. If it was sick or had
a high fever, these things will be preserved and carried right through
the animal's lifetime."
Mann spends his summers in southwestern France, studying the teeth - and
other surviving bits and pieces - of the creatures who immediately
preceded us. The Neanderthals also seem to have overlapped modern humans
in time, which makes them all the more fascinating. The way Neanderthals
have been depicted in the popular press, however, disturbs Mann. In the
absence of clear evidence, humans speculate and project their own
feelings onto other folk. The Neanderthals were unfortunate enough to
"conform to our expectation of what the brutish should look like: they
had low foreheads, big brow ridges, big projecting faces. If you go back
and read Conan Doyle, for example, when Sherlock Holmes talks about the
typical and habitual criminal, that criminal has the same features. It's
common in our culture to depict the brutish in those terms." Such
stereotypes arose, at least in part, from forms of racism that have now
been widely discredited. "Some years ago, Europeans could treat other
living humans as less evolved than themselves. That's almost impossible
to do these days, but dead Neanderthals may serve as handy substitute
'whipping persons.'" It's easy to feel superior to a hulking "cave man"
who carries a club over his shoulder and speaks only in grunts.
This cartoon version of Neanderthal becomes more sophisticated, even
sympathetic in novels like those of Jean Auel or William Golding. Still,
the ancient creatures are presented as limited, incapable of language,
and on their way out. Superior modern humans will inherit the world from
them. Yet, says Mann, we have no real evidence for Neanderthals'
supposed inferiority. "They were very successful in living through
difficult climatic and environmental conditions in Europe. They had
brains at least the size of ours. They were capable of making stone
tools. They buried their dead. But many of us refuse to share humanity
with them. Now there is a move afoot in my field to deny them the
appellation of Homo sapiens. Some scholars posit a separate, long,
dead-end evolution for them.
I honestly do not know how they are related to us, and I can tell you
that nobody else does. The question should be left open. We can't answer
it yet from the existing fossil record."
It's important to Mann to try to make his field as scientific as
possible. "That means looking for data, collecting evidence,
interpreting it as far as we can - but we must stop short of making up
fairy tales that go beyond what we know, into the realm of what we think
we know or would like to know." While he enjoys the novelists'
imaginings about prehistory, he sometimes wonders if his colleagues
don't project more of themselves onto the past than they realize. For
instance, going out to dinner with other anthropologists at conferences,
Mann started to notice that "virtually all of them will attack their
meat first. Some will eat their veggies, but a lot will leave them
aside. Then we go back to the conference and talk about the evolution of
hunting. It's a central theme. What would happen if a group of
vegetarians from another culture were to reconstruct our past? Would
they put all that emphasis on hunting?"
He concedes with a smile that our ancestors ate some meat because of the
broken bones at their sites. But how much did they eat? Did they delight
in it? Was it only an occasional pleasure, hard to come by and less
important than other foods in the total diet? "How many insects did they
eat? For our culture the notion that our ancestors consumed lots of
insects is difficult to take. Yet this is an available resource with
wonderful nutrition." In the Biblical book of Leviticus, grasshoppers
and locusts are specifically mentioned as being kosher foods. Combined
with grains, says Mann, they yield a complete protein. Of course, no
insect would be preserved in an early site. Vegetation, fruits, tubers,
all disappear almost completely. Their absence was part of what led
Robert Ardrey to argue, in a book called African Genesis, that our
australopithecine ancestors evolved on the open savannah lacking any
vegetable food sources. That's why they became "killer apes," always on
Another famous book built its own just-so story on top of this "mighty
hunter" theme. "Desmond Morris, in The Naked Ape, tried to justify the
then current situation in which males were dominant and females
subordinate in most human societies. So he reconstructed early hominid
males as going out hunting for food while the females sat around the
fire and collected a medicinal herb or two. They also developed their
sexuality to lure the guys back from the bush with the food; otherwise
females would have starved to death." And that is why human females are
still subordinate to the males who bring home the bacon, or whatever is
considered tasty. "Morris wanted to understand a modern scenario, went
back into the past (with his own preconceptions), reconstructed the past
from the present point of view, and then turned around and justified the
present on the basis of this reconstructed past."
Our ancestors are extinct, Mann notes, and so are their ways of life.
"Using models from any living animal is fraudulent. The living are not
like the extinct. When we look at the earliest bipeds, Lucy and others
from three million years ago, what do we know about them? They were
social. They walked like us, but we don't know why they became
upright-postured creatures. We don't find stone tools associated with
them until almost the end of their evolutionary time. They had brains
the size of chimpanzees' or a little larger in a skull with ape-like
proportions. Even the earliest did not have the large tusk-like canine
teeth of apes. They also had something truly bizarre - huge back grinding
teeth. About one and one-half times the size of a modern human's.
We don't know what those teeth were adapted to. We don't even know what
kind of environments early hominids lived in. The fossil record
documents that our ancestors were there, but more than that we cannot
Will we ever be able to say more?
"For the early phase of evolution, it will be a very long time before we
gain any more insight. It will take a huge amount of data collection,
plus the introduction of very sophisticated techniques. For example,
developments in bone chemistry may give us insights into the kind of
diet these early creatures were eating. We may come to more fully
understand the underlying genetic mechanisms of patterns of growth and
development. This was what my research was on 30 years ago. A book I
wrote on the australopithecines attempted to understand how they grew.
Did they have a prolonged childhood like humans or a more abbreviated
pattern like apes? I used the dentition as a way of calibrating their
growth and development. This was accepted, and then in the mid '80s it
began to be challenged. There is now an enormous debate focusing on the
Mann suspects that answers will be so long in coming that he has chosen
to concentrate these days on the nature of modern human origins.
Particularly, on our relationship to the Neanderthals. It tantalizes him
that human fossils from the last 200,000 years of our evolution have
been sought - and discovered - in so limited a geographical range. "From
northern Iraq to the China Sea, there's not a single human fossil. I
have a research appointment at the University of Bordeaux for several
months of the year, and I'm developing a project to go to south Asia
with some French colleagues. A joint expedition to look for the fossils
of humans who were contemporary with the Neanderthals in Europe. At the
moment, there's a theory that modern humans originated in Africa and,
for unexplained reasons, swept out of Africa, to destroy or at least
replace species like the Neanderthals. Is this true? I would like to
look for fossils in south Asia where there hasn't been much
He knows that we will continue to do a lot of speculating and tell a lot
of fairy tales about our ancestors, but he would like for everyone "to
know exactly what we have" in the way of real evidence. "These creatures
had a combination of features that you cannot find in any living form.
That is a fantastic thing. It's wonderful that our discoveries have
documented as much of our past as they have."
Alan E. Mann received his Ph.D. from the University of
California, Berkeley, and came to Penn as an assistant profesor
in 1969. He is currently professor of anthropology and curator of
the physical anthropology section of the University Museum. He has
written numerous articles on human evolution and his textbook with
M.L. Weiss, Human Biology and Behavior, has been issued in
several editions. In addition to his regular field work and
writing, Dr. Mann is a dedicated teacher and has won the Lindback,
Ira Abrams, and College Alumni Society awards for outstanding teaching.