BOOK REVIEWS
Origin of Human
Bipedality
The Evolutionary Key to Becoming
Human
By C. Stanford (2003) Boston: Houghton
Mifflin Company. xx
204 pp. ISBN 0-618-
30247-6 (cloth) $23.00.
Lowly Origins: Where, When, and Why
Our Ancestors First Stood Up
By J. Kingdon (2003) Princeton, NJ:
Princeton University Press. ISBN 0-691-
05086-4 (cloth) $35.00.
There is a story, perhaps apocry-
phal but befitting his style, about the
late Tibetan scholar and meditation
master, Cho¨gyam Trungpa Rinpoche.
When a student asked him why our
ancestors stood on two legs, he re-
plied, “a sense of humor.” Playfulness
may well have had a role in such an
innovation but, beyond that, a sense
of humor is useful in approaching the
subject of the origin of bipedality.
Clues exist in the fossils and habitats
of those early ancestors and in their
living descendants. Nevertheless,
those first steps in our lineage will al-
ways be obscured from our full view.
Such obscuration implies uncertainty
and uncertainty invites differences of
opinion. As with geopolitics these
days, aggressive conflicts inevitably
develop. But delightful curiosity can
be cultivated even among scholarly
gladiators.
Craig Stanford’s book, Upright: The
Evolutionary Key to Becoming Hu-
man, is written for a popular audience
in an informal tone common to sci-
ence writing. It is good when such a
style of writing is mastered by a well-
trained scientist who has the inspira-
tion, does the arduous work, and cites
the scientific literature in which the
study is embedded. Stanford writes
clearly, takes other views into ac-
count, and has the research experi-
ence (at least sixteen field seasons) to
earn our gratitude and respect as one
who knows first-hand the behaviors
and ecology of the African great apes.
This book is easy to read. It is based
on the experiences and readings of an
author who is well informed. Stanford
has this to say about exactly why bi-
pedalism arose in our ancestors: “We
don’t need great imagination to con-
sider how this scene might have
played out early in human history.
Same forest, similar ape. But when
the ape spots a small tree growing a
few feet farther away from the last, he
awkwardly takes three steps across
the forest floor while standing up-
right, then sits down on his haunches
to continue feeding at the new site” (p.
118).
A little later, he asks, “But why did
the impetus for change occur at all?
The environment in East Africa at five
to six million years ago was changing,
but savannas were not simply replac-
ing forests, as we have seen. Instead,
the type of forest was changing, from
dense and closed to more open, as
rainfall declined and the degree of
seasonality rose. The distribution of
preferred foods in those forests also
changed as a result. Fruit trees that
grew in closely packed stands become
more dispersed; thickets that once
grew like carpets now became patch-
work quilts. To move about in these
patchwork arrangements, even for
just a few miles, hominids increased
the frequency of their bipedal walk-
ing” (p. 120).
Stanford’s ideas on the origin of bi-
pedality arise from his experience in
studying chimpanzees and gorillas in
their natural context. In this book he
reports his observations of bipedality
in chimps in the wild and notes that it
occurs in feeding situations. This con-
firms Kevin Hunt’s
1,2
observations
and adds to the bank of evidence that
bipedalism arose in the context of
feeding. According to Stanford, later
improvements in bipedality in the ge-
nus Homo came when meat became
important in our ancestors’ diet.
Stanford is clearly writing for a pop-
ular audience and not for his col-
leagues. He perpetuates the practice,
all too common among scientists-
turned-science-writers, of mocking
previous work to bolster his own
ideas.
3
For example, he states, “Rod-
man and McHenry, along with Love-
joy, Stern, Susman and the others, op-
erate in a black-and-white world
where one is either a good biped or a
poor biped” (p. 120). While it is nice to
be grouped with one’s distinguished
colleagues, this statement is offen-
sively false. Here is what two of these
colleagues actually said:
It is likely that Miocene homi-
noids were not as efficient bi-
peds as modern humans; it
might be expected, without ex-
amination of observations pre-
sented here, that there was a pe-
riod of awkward, inefficient
transition through an adaptive
trough separating quadrupedal
from bipedal walking by the an-
cestral hominoid. If so, some
special advantage would have to
exist for evolution of bipedalism
to occur. But Taylor and Rown-
tree found that for chimpanzees,
the costs of quadrupedal and
bipedal travel are the same. We
interpret their results to show
that there was no energetic rubi-
con separating hominoid qua-
drupedal adaptation from homi-
nid bipedalism. Under a
selective regime favoring ener-
getic efficiency, structural varia-
tions in the direction of im-
proved bipedal walking (which
must have existed for bipedalism
to evolve for any reason) could
have been favored quickly with-
out the problem of crossing an
intuitively likely, but manifestly
nonexistent, adaptive trough in
the transition.
4
Although Stanford does not give
credit to anyone, the idea that envi-
ronmental change and widening food
patches provided impetus for bipedal-
ity is an old one, going back at least as
far as Darwin (1872). One can hope
that the public will not perceive this
idea as the “Stanford Hypothesis” be-
cause it did not first arise here nor on
a California campus. The priority of
this idea is expressed in the following
passage, in which Rodman and
McHenry
4
carefully reviewed the his-
© 2004 Wiley-Liss, Inc.
Published online in Wiley InterScience
(www.interscience.wiley.com).
DOI 10.1002/evan.20000
Evolutionary Anthropology 13:116–119 (2004)

tory of this environmental hypothesis
and explained it in reasonable detail:
The most widely accepted sce-
nario for the origin of bipedal-
ism follows Haeckel
5
and Dar-
win
6
bipedalism arose when our
primate ancestor came to live
somewhat less in the trees and
more on the ground “...owing
to a change in its manner of
procuring substinence, or to a
change in the conditions of its
native country” (Darwin, 1872:
135). Substinence change may
have been involved,
7
but a more
conservative view is to propose
that the initial hominoid-homi-
nid divergence did not involve a
dietary change, but merely a
change in the distribution of
typical hominoid food sources.
According to this hypothesis,
ancestral hominids were faced
with a foraging regime that de-
manded more travel for the
same food intake, thus selecting
for improved energetic efficiency
of terrestrial travel between food
sources. It is well known that
climatic fluctuations in the Mio-
cene led to changing distribu-
tions of forest and open coun-
try.
8,9
In areas of receding
forests the ancestral populations
faced a foraging regime in which
food was more dispersed and
demanded more travel to har-
vest, assuming diet was not
modified at first. Although struc-
tural modification in the direc-
tion of improved quadrupedal
efficiency might have occurred,
this route would have conflicted
with ability to harvest food at
food sources. Bipedalism pro-
vided the possibility of improved
efficiency of travel with modifi-
cation only of hindlimbs while
leaving the hominoid structure
of forelimbs free for arboreal
feeding. We therefore concur
with Romer, as have others,
10
that the hominid ancestor ‘may
have evolved potentialities as a
ground walker so that he could
live successfully in the
trees...’”
11
(p. 105).
Jonathan Kingdon’s book is quite
different. He found the title of his
book in Darwin’s
6
final words in the
Descent of Man: “...Man, with all his
noble qualities—with his god-like in-
tellect which has penetrated into the
movements and constitution of the so-
lar system—with all these exalted
powers—man still bears in his bodily
frame the indelible stamp of his lowly
origins.” As Kingdon points out, it is a
fitting title for a book that focuses on
the evolutionary transformations
from the low body profile of a quad-
ruped, particularly, as he suggests,
one that went through a squatting
stage, before rising up on its hind-
limbs.
Lowly Origins is rich in ideas and
data on many topics, but its pro-
claimed focus is on the origin of bipe-
dalism. On this topic, the book brings
a fresh perspective arising from the
author’s special background and tal-
ents. Kingdon grew up among Afri-
cans and African environments with
youthful curiosity about natural his-
tory. This work is unique because of
his unique abilities and style. Kingdon
is a zoologist whose multi-volume
book on East African mammals
12
is a
classic. Further, his beautifully illus-
trated and thoroughly researched
guide, The Kingdon Field Guide to Af-
rican Mammals,
13
is an essential ref-
erence. He is an artist and has a paint-
er’s eye for precise observation: Lowly
Origins is enriched by figures that are
mostly his drawings. Kingdon has
spent his life in Africa learning its fab-
ulous natural history. He reads
widely, as one can tell by the detailed
referencing of every sentence (al-
though there are numerous inaccu-
rate citations). He is quick to adopt
new perspectives, as revealed, for ex-
ample, by his interpretations of the
variability of the genetic sequence on
the Y chromosome. He writes with a
generous spirit that is open to new
ideas and shows concern for our pre-
cious little blue planet. He also writes
with clarity and in a style that reveals
a strong and experienced mind at
work. For example, the following de-
lightful passage describes his explora-
tions in Uganda:
Clambering over these long-dead
screes with pioneering field
palaeontologists Bill Bishop and
Sonia Cole was to time-travel in
visionary company....While
camping in Karamoja, our
search for fossils had none of
the character of a grim forensic
science; it was recovering events,
lives, and ecologies as full of vi-
tality as anything happening to-
day. Holding a toothy bit of jaw
on his left palm, Bill’s right hand
swept over the invisible contours
of a chimp-sized skull that had
once inhabited a living primate
yet, at this moment, existed only
in the imagination of a single
person. It was an imagination
that searched not only for more
bits of a 20 million-year-old pro-
toape in the cinders of long dead
volcanoes but also sought to en-
compass the environment and
evolutionary meaning of extinct
hominins in eastern Africa. Big
Bill, the geologist, puzzling over
what rocks and formations to
search next for that meaning.
The feeling that we were wit-
nesses to our own evolutionary
history began to take hold there,
on the gravel of Lolim, but I was
impatient to clothe the bones
with flesh and life...Now,
many years later, time-traveling
imaginations have been led
down trails that wind along
some very unexpected routes. As
apparently disconnected facts
accumulate, I’ve been joined by
new generations of puzzlers
seeking patterns from numerous
new sources of evidence—not
only more fossils, but a whole
new genetics and new Darwinian
insights from the ecological and
behavioral sciences” (p. 80–81).
So what does Kingdon’s lively prose
add to the long history of ideas on the
origin of bipedalism? First is his au-
thoritative perspective. He is a rare
individual with great depth and first-
hand experience of African biogeogra-
phy and mammalian diversity and
evolution. This background has led
him to specific ideas about how the
major events in our evolutionary lin-
eage occurred. He proposes two new
steps in our history: After the com-
mon ancestor of chimps, gorillas, and
people evolved in Africa, where Moro-
topithecus developed the typically
hominoid upper body, it spread to
Eurasia, where Dryopithecus and
BOOK REVIEWS Origin of Human Bipedality 117