LINEBURG


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be looking in some detail at the notion of universal humanity and
discovering how the concept of an anatomically modern human, the
agent provocateur of the Human Revolution, arose as a scientifically
meaningful adjunct to the study of Homo sapiens, ourselves, as a diasporic
species with global coverage.


Enter anatomically modern humans
Thirty years exactly separates two major archaeological discoveries in
Ethiopia. The first was made in 1967 by a team led by Richard Leakey
(1969) searching the Omo Valley in the south-west of the country. Here, in
the Kibish geological formation, they found the fossilised remains of three
adults, one represented by a nearly complete skull but without a face
(Omo II) another by a skull fragment (Omo III) and the last by a partial
skeleton (Omo I). No stone artefacts were found with them and their age
was originally established as 130,000 years old but has recently been revised
using new techniques to 195,000 (McDougall et al. 2005). The bones of all
three individuals were heavily mineralised but un-distorted by the
sediments and revealing no pathology (Leakey et al. 1969:1135). The real
interest lay in Omo II. Its high forehead, large brain case and generally
gracile features marked it out as human not hominin. Only the cranial
vault survived but this was sufficient for its interpretation as a ˜very early
representative of Homo sapiens™ (Leakey et al. 1969:1132). This made it the
earliest human fossil anywhere and firmly pointed to Africa as our centre of
origin.
Subsequently Ethiopia has continued to yield important discoveries,
the most famous of which was the 3.7 million year old Australopithecine
known as Lucy (Johanson and Edey 1981). However, in 1997 a joint
American-Ethiopian team working in the same Afar depression where Lucy
was discovered uncovered three crania in the Herto Bouri area (White et al.
2003). This time the finds represented two adults and one immature
individual. Moreover, the bones were found with stone tools. Advances
since 1967 in absolute dating using radio-isotopes and tephro-stratigraphy
have dated all the evidence to between 160,000 and 154,000 years ago
(Clark et al. 2003). The morphology of the skulls, combined with these
ages, led Tim White (White et al. 2003:742), before the new dating of
36 Origins and Revolutions

the Omo skulls (McDougall et al. 2005), to conclude that they ˜represent
the probable immediate ancestors of anatomically modern humans™.
He recognised their pivotal position by naming them as a sub-species,
`
Homo sapiens idaltu; Idaltu in the Afar language means elder.
The key-word that has been added to human evolution in the thirty years
that separate these two important discoveries is not, however, idaltu but the
two qualifiers to either human or Homo sapiens. These are ˜anatomically™
and ˜modern™. But why were they applied? Surely Homo sapiens needs
neither? ˜Homo know for yourself™, was Linnaeus™ (1800) comment to
his classification of humans, and if we can™t who can? Moreover, if humans
need the prefix ˜modern™ then why not, as anthropologist Tim Ingold
(1993a:388) has asked, ˜anatomically modern™ elephants to distinguish them
from their geological ancestors?
The anatomically modern human is a hybrid concept that accommo-
dates information from archaeological and anatomical sources that are
apparently contradictory because they challenge established classifications.
The Herto hominins provide a case study. The stone tools come from an old
tradition, the Acheulean, that first appears in Africa one and a half million
years ago associated with the species Homo ergaster. In Africa it has two
trademark artefacts À handaxes and cleavers À both of which are large
bifacial stone tools. However, the Herto bifaces and the means by which
the raw material was knapped into stone flake-blanks reflect advances in
stone working that are at most 300,000 years old. The Herto material is
therefore regarded as final or ˜transitional™ Acheulean (Clark et al.
2003:750). In this case the transition is towards a Middle Stone Age when
bifaces drop away and a variety of smaller tools are fashioned from blanks
that were knapped from stones in a novel ordered sequence (Chapter 7).
But the Herto skulls also carry further information. They had been
deliberately modified after death. The alterations took the form of cut
marks consistent with the removal of the mandible followed by defleshing
the skull. Then two of the crania were deliberately polished and scraped
(Clark et al. 2003:751). At a much earlier date the Bodo skull, also from
Ethiopia, has cut marks indicating defleshing but no further signs, as seen
on the Herto skulls, of the kind of modifications that archaeologist
Desmond Clark (Clark 2003:751) refers to as decoration.
So, the Herto trio bear witness to deliberate mortuary practices that
could be modern, a basically archaic tradition of making stone tools and
a transitional skull morphology. They are accorded sub-species status at the
boundary of being anatomical modern humans. On the other side of the
fence the Omo trio carry less information but shortly after their discovery
The Human Revolution 37

table 2.1. Recognising anatomically modern humans, Homo sapiens
(Stringer and Andrews 1988:1263)

1. All living humans are characterised by a gracile skeleton in comparison with
that of other species of the genus Homo. In particular this applies to,

• longbone shape and shaft thickness
• the depth or extent of muscle insertions
• the relatively thin bone of the skull and mandible

2. The cranium is voluminous, but no more so than in Neanderthals,
and like the brain it contains is typically short, high and domed
3. The supraorbital torus (browridges) and external cranial buttressing
are either considerably reduced or absent
4. Teeth and jaws are reduced in size
5. Probably as a result of smaller teeth, the face is tucked well under the
forehead rather than sloping forward
6. A mental eminence (chin) is present on the mandible from a young age


David Brose and Milford Wolpoff (1971:1183) included them in a group
they called ˜anatomically modern Homo sapiens™.


Defining the fully modern human: bodies, brains and boats
The anatomical ideal that human palaeontologists are working towards has
been summarised by Chris Stringer and Peter Andrews (1988) (Table 2.1).
But having the body, and most importantly a face and head, that fits
the variation shown by modern humans is not enough. There would
be no need for the qualifiers ˜anatomically modern™ if they were also
˜fully modern™ in the cultural sense. With the introduction of ˜fully™ as
a qualifier the bar is raised by archaeologists to a height that only a
revolution might clear.
Richard Klein (1995:169) for one has questioned if all the anatomically
modern humans in the fossil record had the same biological endowment of
the fully modern brain. Without the demonstration of behavioural
modernity they would remain in an outgroup to humanity, like Homo
sapiens idaltu. Could they all talk, make images, conceive of an afterlife,
remember their ancestors and plan ahead for next year? Were anatomically
modern humans the ultimate hardware waiting for a software upgrade,
and if so was this on a revolutionary time-scale? Language is given particular
prominence and the so-called ˜language gene™ FOXP2 is proposed by
38 Origins and Revolutions

Klein as that missing bit of code, although others remain unconvinced
(Carroll 2003).
Although they disagree with Klein™s recent Human Revolution, Sally
McBrearty and Alison Brooks (2000:492À3) are nonetheless confident that
fully modern human behaviour can be characterised in cognitive and
cultural terms (Table 2.2).
Their scheme sets out what many archaeologists regard as a workable
definition of humanity; workable in the sense that data do exist to back up
the descriptions and so provide insights into the tempo as well as the
geographical origin of change. But would anyone outside archaeology
recognise those four cognitive skills À planning, symbolic behaviour,
abstraction and innovation À as an adequate definition of what it is to be
human? Even within the subject Francesco d™Errico (2003:189) regards
their list as very limited and pre-judgemental of the outcome they want;
namely that the Human Revolution has been overstated by judicious use
of the European data and misrepresentation of the African evidence.
Although they provide a check-list (Table 2.2) and a timetable it is
McBrearty and Brooks™ (2000:534) opinion that the unique behaviours
of modern humans that would qualify them for the ˜fully™ prefix are to
be discovered rather than prescribed. But here they become caught in
the circularity common to all such archaeological exercises in origins
research.
Is there an alternative? Elsewhere (Gamble 1993a; 1998) I have argued for
a social explanation rather than either a cognitive re-organisation or genetic
mutation to account for the differences in the archaeology. One striking
feature of world prehistory after 60,000 years ago is that it is for the first time
just that, a world prehistory. After this date Homo sapiens began their
diaspora and in less than 1 per cent of the time since we last had a common
ancestor with our closest primate relatives, the chimpanzees, we had
migrated to the previously uninhabited islands and continents that before
made up almost three-quarters of the Earth. From being a hominin long
confined to a portion of the Old World we suddenly became global
humans. Furthermore, for the first time in our evolutionary history we
became a single species differentiated only by geographical variation. What
we see in those ocean voyages, and the settlement of the seasonally cold
interiors of continents, is a clear geographical signature that social life was
fully released from the constraint of proximity (Rodseth et al. 1991) that
explains why most primates are not world travellers. What characterises
social life in humans rather than hominids is our ability to extend social
relations across space and through time, a theme I return to in Chapter 8.
The Human Revolution 39

table 2.2. Modern human cognitive and cultural capabilities and their tangible
archaeological traces in Africa (after McBrearty and Brooks 2000:492À3)

Cultural capabilities and archaeological
Cognitive skills and definitions evidence
The ability to formulate Evidence reveals human
Planning Technological
strategies based on past inventiveness and
depth
experience and to act capacity for logical
upon them in a group thinking
context
The ability to represent Features of the record
Symbolic Symbolic
objects, people and demonstrate a capacity to
behaviour
abstract concepts with imbue aspects of
arbitrary symbols, vocal experience with meaning,
or visual, and to reify to communicate abstract
such symbols in cultural concepts, and to
practice manipulate symbols as a
part of everyday life
The ability to act with Aspects of the record
Abstract Ecological
reference to abstract reflect human abilities to
thinking
concepts not limited in colonise new
time and space environments, which
require both innovation
and planning depth
Behavioural, economic Features show human
Innovation Economic
and technological abilities to draw models
and social
from individual and
group experience, to
develop and apply
systematic plans, to
conceptualise and
predict the future, and to
construct formalised
relationships among
individuals and groups


This is in marked contrast to all our primate cousins whose social life is
based on local co-presence.
I don™t doubt that either the Herto or Omo trios had the capacity for
global dispersal. Evidence from well travelled raw materials shows that
40 Origins and Revolutions

social extension occurred (Merrick and Brown 1984). However, for some
100,000 years these people who looked like us decided to stay at home in
the Old World. In this instance it is therefore by comparison with our
diasporic distribution that the later, social revolution through a release from
proximity emerges. To qualify human with either ˜fully™ or ˜modern™ is
therefore unhelpful because it obscures in this instance the historical
process of change.


The Human Revolution; ancient and modern
What had happened in the thirty years between these two Ethiopian
discoveries was a fierce debate about the evolution of people like ourselves.
One tradition, beginning with Franz Weidenreich (1943) and promoted
by Carleton Coon (1962), argued for multi-regional evolution. Following
an initial early expansion out of Africa by Homo erectus the various
regional populations that were then established in Europe and Asia evolved
into the populations that inhabit those areas today. Multi-regionalists,
forcefully led by palaeoanthropologist Milford Wolpoff (1988; 1989),
interpreted the scattered fossils as evidence for parallel evolution,
mostly in isolation, although limited gene-flow between populations
was allowed in later versions. The in-situ evolution in Europe from
Neanderthal to modern human populations was a crucial test case for
regional continuity due to the relative quantity of information in a subject
otherwise characterised by poor samples. Wolpoff regarded both forms as
Homo sapiens, with no need for any further sub-species qualification.
But what multi-regional evolution had to demonstrate was the repeated
transition from what everyone regarded as one distinctive anatomy to
another.
Brose and Wolpoff (1971) tackled this issue by arguing for the appearance
of a more efficient stone technology. This advance reduced the previous
use of teeth for cutting as well as the application of the jaw as a vice.
In addition, Loring Brace (1979) proposed a ˜culinary revolution™ where
cooking food to make it softer now changed the selection pressures on teeth.
In short, there was no longer any need for big powerful teeth or rugged
musculature and bone structure. The knock-on effects for cranial mass and
shape were considerable. Tools, teeth and faces co-evolved so that we
unintentionally created the way we look. In technical terms:
The loss of the distinctive Neanderthal cranial form is a direct
consequence of selection relaxation for the anterior dentition and
The Human Revolution 41




figure 2.1. Candelabra, or multi-regional, hat-rack, or unilineal, and single origin
models of human evolution (after Howells 1967:236; Stringer and Gamble 1993).
Hat-rack models invariably matched the three fossil stages to the Lower, Middle and
Upper Palaeolithic periods. The candelabra model relaxed this strict association
between biology and culture.


supporting facial architecture, and resulting change in selection acting on
the static and dynamic properties of the nuchal musculature.
(Brose and Wolpoff 1971:1185)

The model of regional continuity produced what William Howells
(1967) described as a candelabra model of human evolution (Figure 2.1).
Although preferable to the older hat-rack model, the result of some drastic
pruning of the human family tree by evolutionary biologist Ernst Mayr
(1950), the candelabra alternative still had problems.
Its difficulties were exacerbated by more fossil and archaeological
discoveries, advances in dating and the reconstruction of population
history using genetics which, when combined, provided the evidence for an
alternative, single origins model. The model™s foremost advocate has been
human palaeontologist Chris Stringer (1996) who argues for a recent
African origin for all modern peoples, citing as evidence fossils such as the
Omo trio. However, the classification of fossil skulls is notoriously difficult
and contentious. On occasion authors of the same article have disagreed
over the fossil they are describing and each assigned it to a different species
(e.g. Walker and Leakey 1978). The jury would still be out if human
ancestry depended upon the fossils alone. The clinching argument came in
1987 with the publication of a genetic tree (Cann et al. 1987) based on the
inheritance of mitochondrial DNA (mtDNA) that is restricted to the
maternal line. Their sample of 148 women from the world™s five major
geographical populations demonstrated that Africans had greater diversity,
and hence were older, than any other biological group. Mutation rates, the
42 Origins and Revolutions

so-called molecular clock, estimates an age of between 150,000 and 300,000
years ago for the founding of the present mtDNA lineage.
The recent African origin model expects multiple dispersals rather than
a single African exodus (Lahr and Foley 1994; Lahr and Foley 1998), and for
whatever reason these recent dispersals of anatomically modern humans
led to the replacement of older regional populations. Among those replaced
were the Neanderthals of Southwest Asia and Europe (Bar-Yosef 1998;
Stringer and Gamble 1993) and the dwarfed hominins, Homo floresiensis,
from Indonesia (Brown et al. 2004; Morwood et al. 2004).
To explore the implications of a recent single origin Chris Stringer,
together with archaeologist Paul Mellars, organised a conference in 1987
that brought supporters of both African and multi-regional models
together. Significantly they titled the book that followed The Human
Revolution: behavioural and biological perspectives on the origins of modern
humans (1989). Of course this was not the first reference to a Human
Revolution. Anthropologist Ashley Montagu, the tireless opponent of
biological racism, had described the human revolution almost twenty-
five years earlier (1965:15) as the moment when stone tools were first
made. On present evidence this would be almost two and a half million
years ago and not the 30À50,000 years ago that many of the contributors
to Mellars and Stringer™s volume expected. The human revolution for
anthropologists Charles Hockett and Robert Ascher (1964) was similarly
ancient. They examined bipedalism, language and environmental change
and concluded:
As soon as the hominids had achieved upright posture, bipedal gait, the
use of hands for manipulating, for carrying, and for manufacturing
generalized tools, and language, they had become men. The human
revolution was over.
(Hockett and Ascher 1964:145, my emphasis)

The point about the Human Revolution as outlined in the 1989
publication was that it was recent. To emphasise its late appearance
in human evolution it is also known as the symbolic revolution, when
representational art appears for the first time; a revolution best summed up
by the title of John Pfeiffer™s (1982) review: The creative explosion. This
revolution was associated by William Noble and Iain Davidson (1996) with
the appearance of language, by Steven Mithen (1996) with a fully modern
modular brain characterised by cognitive fluidity, by Lynn Wadley
(2001:210) with evidence for external symbolic storage (art, ornamentation,
style in lithics and the formal use of space) and by Robin Dunbar (2003:179)
The Human Revolution 43

table 2.3. The major changes between the Middle and Upper Palaeolithic
in south-west France (Mellars 1973; Mellars 2005:Figure 1) has more recently
identified fifteen innovations that mark the Upper Palaeolithic revolution
in Europe

Material technology
A greater range and complexity of tool forms and a replacement of stability in
Middle Palaeolithic tool forms with rapid change during the Upper Palaeolithic;
a development in bone, ivory and antler working; the appearance of personal
ornaments

Subsistence activities
A greater emphasis on a single species (often reindeer); a broadening of the
subsistence base to include small game; the possible development of large scale
co-operative hunting and a greater efficiency in hunting due to the invention
of the bow and arrow; very possibly these changes were accompanied
by improvements in food storage and preservation techniques

Demography and social organisation
A substantial increase in population density and the maximum size of the
co-residential group as inferred from the number of sites and the dimensions
of settlements; group aggregation occurs to participate in co-operative hunting
of migratory herd animals such as reindeer; increase in corporate awareness



with the late appearance in human evolution of a theory of mind capable of
the cognitive gymnastics implicated in religious beliefs.


Revolutions that were and weren™t
I trace the theoretical roots of this recent Human Revolution to Paul
Mellars (1973) and Richard Klein (1973) writing respectively about the
Palaeolithic of south-west France (Tables 2.3 and 2.4) and the Ukraine in
the period 40À50,000 years ago. What they produced, reviewed recently
by Ofer Bar-Yosef (2002:365À9), were a list of traits to measure the tran-
sition between two archaeological periods, the Middle Palaeolithic of
Neanderthals and the Upper Palaeolithic of modern humans. Klein
(1973:122) concluded that the ˜Upper Palaeolithic appears to constitute a
quantum advance over the Mousterian (Middle Palaeolithic)™; a revolution
in all but name.
To begin with the focus was very much on Europe but Klein in particular
broadened the enquiry to include southern Africa so that twenty years later
44 Origins and Revolutions

table 2.4. Klein™s updated ten-point check-list of traits of fully modern
behaviour detectable in the archaeological record beginning 50À40,000 years
ago (Klein 1995). The scale is worldwide

1. Substantial growth in the diversity and standardisation of artefact types
2. Rapid increase in the rate of artefactual change through time and in
the degree of artefact diversity through space
3. First shaping of bone, ivory, shell and related materials into formal artefacts,
e.g. points, awls, needles, pins, etc.
4. Earliest appearance of incontrovertible art
5. Oldest undeniable evidence for spatial organisation of camp floors,
including elaborate hearths and the oldest indisputable structural ˜ruins™
6. Oldest evidence for the transport of large quantities of highly desirable
stone raw material over scores or even hundreds of kilometres
7. Earliest secure evidence for ceremony or ritual, expressed both in art and
in relatively elaborate graves
8. First evidence for human ability to live in the coldest, most continental

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