AS science evolves, do its theories circle ever closer to objective truth? Or
do scientists lurch between “paradigms” in response to the social forces of the
day?

Not surprisingly, scientists tend to prefer the objective truth version,
sociologists the lurching paradigms. But what both sides share is a passion for
arguing their case—armed with much mud and vitriol.

The philosopher Michael Ruse enters the fray armed merely with the personal
histories of a dozen evolutionary theorists from the past two centuries. Brave
or foolhardy? It’s hard to judge. But Ruse clearly believes that examining the
political and social views of scientists—and looking for connections with
their theories—is one way to weed out objectivity from ideology.

Evolutionary biology certainly provides fertile ground. While Charles
Darwin’s notion that life evolved from a few simpler forms is now beyond doubt,
debate still rages over virtually every other major question. Did life evolve
via incremental changes or rapid bursts of diversification? Are adaptionists
like E. O. Wilson right when they say human behaviour is as much the product of
natural selection and genes as is human anatomy? Or are biologists such as
Stephen Jay Gould and Richard Lewontin closer to the truth when they say that
culture makes us who we are, and that in any case, evolution does not proceed by
natural selection alone?

In Mystery of Mysteries, Ruse’s subjects range predictably from
Charles Darwin and Theodosius Dobzhansky to Dawkins, Gould, Wilson and Lewontin.
And in some cases, Ruse does find strong links between scientific and social
outlooks. For example, a desire for social progress, found in the socialism of
Lewontin and the Christianity of Dobzhansky, lies alongside evolutionary beliefs
which make such progress seem at least possible. Nevertheless, over the past two
centuries, Ruse concludes, evolutionary biologists have become more and more
careful to exclude the cultural from the scientific.

That may be true in refereed journals, but the same cannot be said of the
booming popular science book market and press coverage. More importantly, Ruse’s
focus on individual scientists fails to address the central claim of
sociologists. What matters to them is not whether this or that scientist is a
Christian or closet racist but why societies (and scientists) as a whole accept
certain theories but not others. Was it an accident, for example, that belief in
the primacy of genes and competition between individuals took off in popular
culture in the Thatcher and Reagan years? Ruse doesn’t tell us.

In the end, empirical observations and new experiments must surely be the
judge of what is “objective science” and what is social ideology dressed up as
science. The evolutionary theories that have emerged since Darwin are mostly
still too young to be assessed in the way Ruse wants to. Studies of fossils, the
human genome, gene flow and inheritance will provide the ultimate test.
Unfortunately, all this demands patience. Field studies and analytical work must
accumulate. Ruse should set his alarm clock for later in the next century.

FIRE, brimstone and pestilence have ravaged the Earth since the dawn of time, wiping out cities, even whole peoples. Or so the ancient prophets and storytellers would have us believe (there’s a fair bit in the Bible). But could they possibly be describing real events?

As a renowned authority on tree rings and their use in dating ancient artefacts and events, Mike Baillie might seem an unlikely author for a book which tackles a lot of mythology. But he’s a perfect candidate, since he recently helped complete a 5000-year continuous and global record of annual growth patterns. It revealed five major worldwide environmental shocks. To find out what they meant he turned to the early texts.

His conclusion comes as a shock. Not only did the five episodes coincide with the onset of “dark ages” for society, but they were triggered by cometary impacts. If Baillie is right, history has overlooked probably the single most important explanation for the intermittent progress of civilisation. Worse, our modern confidence in benign skies is foolhardy, and our failure to appreciate the constant danger of comet “swarms” is the result of a myopic trust in a mere 200 years of “scientific” records. Our excuse is that Christianity probably suppressed the dire warnings of earlier sages in an effort to downplay their influence, as Baillie points out.

The tree-ring record points to global environmental traumas between 2354 and 2345 BC, 1628 and 1623 BC, 1159 and 1141 BC, 208 and 204 BC and AD 536 and 545. Baillie argues that the tree rings are recording first the Biblical flood, then the disasters that befell Egypt at the Exodus, famines at the end of King David’s reign, a famine in China that ended the Ch’in dynasty, and finally, the death of King Arthur and Merlin and the onset of the Dark Ages across the whole of what is now Britain.

The biblical account of Exodus and contemporary annals from China speak of cometary activity preceding calamity. Previous writers have wondered if the hail of red-hot stones that befell the Egyptians was due to the eruption of Santorini, the Aegean volcano that destroyed Minoan civilisation. The pillar of smoke that guided the Israelites may have been the plume. But a single volcano is an unlikely cause of a global downturn.

So Baillie goes a step further, arguing that a series of cometary impacts around the size of the 20-megaton explosion at Tunguska in Siberia in 1908 might be enough to trigger earthquakes, tidal waves, volcanic eruptions and ocean floor outgassing. This would explain why comets are seen as portent, along with the occurrence of flooding and poisonous fogs-all reported at the time of Exodus and during others of Baillie’s five catastrophes.

As he admits, he has ventured beyond his professional expertise in exploring mythology. Is it correct to assume that references to angels and dragons are descriptions of comets? Science would be much poorer if acknowledged experts felt unable to speculate as Baillie has done here. But science also tends to seek solutions, and if the author is not carried shoulder-high for broaching this important subject, it will be because his doomsday scenario offers little in the way of of an immediate technical fix. If a couple of lumps of interplanetary rock the size of several football pitches hit Europe tomorrow, tens of millions would die. And some astrophysicists reckon that an event of this order is likely at least once every 5000 years-killing at least a quarter of the human population.

Baillie proposes seeding space with our DNA in an effort to survive, but that doesn’t sound quite as much fun as carrying on as we are. Let’s hope both he and the astrophysicists are wrong.

DID you realise that archaeology has its own “big bang”? This is the
so-called “human revolution”, about 40 000 years ago, which is supposed to mark
the sudden onset of artistic and cultural activity. A second cultural great leap
forward is often said to have occurred with the appearance of writing and the
city state around 3000 BC. Richard Rudgley’s Lost Civilisations of the Stone
Age convincingly demolishes these two pillars of the temple of
knowledge.

As tellers of tales and as listeners, we expect a definite beginning and end
to all narrative. Archaeology is also fond of such moments: the first bronze
smelting, the fall of Rome. But it’s an approach that can blind. Take the
question of the origin of writing, which for many years was assumed to have
arisen suddenly, fully formed as cuneiform script in the Sumerian city of Uruk
in about 3300 BC. For decades, archaeologists all over the Near East had been
finding curious geometrical pottery “tokens”. Fashioned between about 8000 BC
and 2000 BC, they had long been a puzzle, and were often ignored or discarded.
Were they from experimental pottery firings, gaming counters, or some part of an
obscure ritual?

Then, in 1992, Denise Schmandt-Besserat described a hollow tablet, discovered
in Nuzi in northern Iraq and dating to the second millennium BC. The egg-shaped
tablet had cuneiform writing on the outside, and 49 tokens inside. The text
proved to be a list of a total of 49 sheep and goats compiled by “Ziqarru, the
shepherd”. The animals were counted in groups by age and gender—and the
numbers corresponded exactly to the differently shaped counters inside the
hollow tablet.

This “new Rosetta Stone”, says Rudgley, meant that other counters could be
deciphered. The conical shape was probably a measure of grain, the ovoid a jar
of oil, the cylinder a domestic animal and the tetrahedron a unit of labour. The
system was used, it seems, to record the tributes offered by successful farmers
to their chiefs or elders for redistribution among the less fortunate. It had
taken a century for archaeologists to realise that the obscure tokens were
examples of a symbolic system that pre-dated writing by five millennia.

In his book, Rudgley argues that archaeological doctrine is deeply
prejudiced against such discoveries because they contradict the artistic and
cultural activity.

But, by scouring many dozens of recent excavations and analyses, Rudgley
finds evidence for an ancient and gradual cultural evolution. It reaches far
back into prehistory and includes the use of symbols, language and music,
weaving, medicine, the use of fire, astronomical observation, tool-making and
hierarchical social structures.

Rudgley sees no need to evoke the lost civilisation of Atlantis and like
tales to explain early advances. He nowhere finds support for such
“unsatisfactory speculation”. He argues that, by clinging to the “cultural
explosion” models, the prevailing doctrine has unwittingly sustained Atlantean
mythology. The notion that culture arrrived suddenly invites myth-making about
the teachings of wise survivors of floods that drowned a golden age.

A fixed distinction between pre-literacy and civilisation is increasingly
untenable, says Rudgley. In any case, the Vinca symbolic script from southeast
Europe pre-dates Uruk’s cuneiform by at least 800 years, and possibly
2000—and did not rely on the city-state found in Sumeria. More importantly
perhaps, the Vinca tradition also bears a strong artistic link to the southern
European culture which fashioned the famous Venus figurines of the Upper
Palaeolithic.

As he goes further back in time to trace the roots of such highly cultured
societies, Rudgley refers to work with which linguists and archaeologists will
be familiar, such as Merrit Ruhlen’s fascinating attempts to reconstruct his
so-called Proto-Global language of prehistoric times. By examining shared word
sounds from languages around the world, Ruhlen concluded that a good fit for the
ancient root of the English word “man” would be “mano”, for example.

The “big bang” model is as vulnerable as the theory of a Rubicon between
prehistory and civilisation. For instance, an incised pebble found in Berekhat
Ram by Israeli archaeologists is possibly a very early female figurine. Though
the natural outline of the stone already resembled the female form it was
improved by a human hand more than 230 000 years ago.

It is a shame that Rudgley was not encouraged to consolidate his important
ideas with at least one general concluding chapter about the broader scientific
implications of his work. An important insight, touched on only in the
introduction, is that the academic overenthusiasm for cultural thresholds in
prehistory is not just an effect of fragmentary evidence but a residue of
19th-century racism in European science—a desire to definitively separate
the “civilised” from the “savage”. It’s a sharp observation, and one that
warrants deeper treatment.

Racists ascribe the purported gulf between “civilisation” and “savagery” to
biological inheritance, of course. But few archaeologists nowadays would claim
that agriculture started in the Near East because of the genetic superiority of
the human populations there. They are more likely to argue that the region
carried a good number of domesticable species and that the population turned to
agriculture during episodes of overhunting.

But by insisting that agriculture, and then writing, marked such a decisive
break with the past, the old racist distinction between civilised and savage is
subtly retained, suggests Rudgley.

The distinction obscures the considerable body of cultural and scientific
expertise of all pre-agricultural humans, everywhere. Forms of land management
were in use for tens of thousands of years in Australia and South Africa, for
instance. The virtually simultaneous appearance of rock art in Europe and
Australia suggests a shared worldwide cultural base. Could art be much older
still, but have failed to survive? It would also have been interesting to know
what Rudgley thinks about the relationship between genetic and cultural
factors in evolution.

To view the Upper Palaeolithic, and perhaps earlier stages in evolution, less
as genetic breakthroughs and more as episodes in a long cultural process would
at least go some way towards explaining the troublesome incompatibility between
the cultural and the anatomical timetable in human prehistory. Anatomically
different populations of Homo erectus and subsequently early
Homo sapiens appear to have fashioned similar Acheulian hand axes.
While later, anatomically modern humans shared Mousterian stone culture with the
Neanderthals. Furthermore, anatomically modern humans first appear more than 100
000 years ago and, so far as we know, were equipped with at least the sensory
and cerebral powers we take for granted today. So if biological endowment was
the trigger why didn’t the Upper Palaeolithic begin then?

As any occasional family camper knows, when confronted in semi-raw nature
with an injured child or lack of fire on a rainy night, our ability to cope
relies not so much on intelligence as on our cultural knowledge of the
principles of first aid and the existence of cigarette lighters. If culture has
been underestimated in prehistory, it’s a compelling argument for doing better
at preserving our remaining range of cultural traditions—for those to whom
we will be the ancestors.

I think I understand what she means. Everyone knows science is important, but
these subjects seem specialised and nerdish. Had it existed, she might have gone
for “science for historians and artists”. She could keep up to date with
cloning, space research and global warming, while enlivening her other subjects
by exploring, say, the shape of galaxies, car design or the role of steam
engines in the Industrial Revolution.

My daughter is not alone, of course, in facing such a dilemma. The post-16
divide has long forced Britain’s arts students to abandon science and vice
versa, no doubt contributing to the well-known lack of scientific understanding
common to both the public and Parliament. It’s a problem that has worried the
country’s leading science organisations for many years. The Royal Society called
in 1991 for a baccalaureate system to allow pupils to study five subjects to age
18, while the Association for Science Education in 1996 called for an “urgent
revision” of science teaching to end its perceived “dehumanisation”,
content-laden syllabuses and low status.

With the election of a Labour government last year, hopes were high for a
radical new approach—extending “science for all” beyond GCSE and revamping
the 50-year-old structure of science subjects. But the government’s
Qualifying for Success proposals, due out this month, are likely to leave
many experts disappointed, if the original consultation document is anything to
go by. It’s true that Labour favours the idea of teaching “key skills” (in
number, IT and communications, ), but its promise to broaden the post-16
curriculum looks like little more than tinkering.

The central proposal is likely to be an extra set of exams after a single
year of A level, leading to an Advanced Subsidiary (AS) qualification. Students
will probably still be expected to complete at least two subjects at A level,
but could offer two AS levels to universities or employers as equivalent to a
third A level. So some pupils might extend the number of subjects from three to
four.

But there seems to be no serious intention of breaking out of the old three
streams of Biology, Physics and Chemistry, or to give science a more modern
look—although one examining board is working on an A level in the Public
Understanding of Science. Rumours circulating in the science education world
suggest that Education Secretary David Blunkett and Downing Street vetoed a more
modular approach.

Organisations such as the Institute of Physics believe that eventually
something even more radical than modules will become essential for future
generations. It wants to allow pupils to chose from a wide range of smaller
units, many more than the half-dozen tightly defined modules currently offered
by a couple of examining boards and taught in only a few schools and colleges.
The institute also fears that the AS exam may turn out to be the worst of both
worlds. It suspects that what is effectively the first year of an A-level
physics course is unlikely to attract many more students, while the specialists
could be held back by the need to cater for a few nonscience students.

In the meantime, the institute is working on a new curriculum it hopes will
ensure that the physics AS content is as broad as possible, will “fire the
imagination” and be “thoroughly up-to-date”.

On 7 April, the institute is hosting the launch of a new post-16 physics
curriculum developed with the help of the Open University, which teaches physics
with units on music, transport, sport, cooking, space exploration, mobile phones
and the environment. The initiative, known as the Supported Learning in Physics
Project, is looking for more funds and has been backed by industry and, to its
credit, also the government.

Unfortunately, any success in this direction will come too late for my
daughter, though if she returns to science later in life as part of Labour’s
“lifelong learning” she will probably find the institute’s approach more
attractive than the old subject headings. So it will be a shame if the
government has not listened carefully to science educators on the need to
broaden and modernise post-16 choices.

And what about us science specialists? I’m in dire need of a crash course in
“arts for scientists”. Hubble bubble, homework trouble . . .

IF YOU’RE thinking of starting a course on human evolution this autumn,
persuade a well-to-do relative to buy you. It’s bang up-to-date, easy to read
and gives a real taste of the state of play in the field. You’ll have the edge
in first-year seminars, and the book will also come in handy for exam
revision.

Lewin’s book is designed for modular courses, with an eye to the US market.
Each chapter stands alone, with the author covering general evolutionary theory,
dating methods and primate studies as well as the core material about our long
journey from apes to agriculture. While this “study unit” structure makes the
book a little disjointed if read from cover to cover, it is entirely suitable
for mugging up coursework.

It’s an unusual textbook in that Lewin is a journalist and writer, not a
university lecturer. This might normally be a disadvantage, but it’s a strength
here. Lewin not only writes well and knows many of the protagonists personally,
but is also soberly objective when reporting rival theories. It is obvious that
he gave his publisher endless trouble by trying to squeeze in all the latest
news.

Lewin is interested in methods as well as results, and rightly dwells on the
developments in DNA analysis of modern populations. This material contributes to
a strong section on the “Out of Africa” hypothesis. Readers will also benefit
from numerous cautionary tales from anthropological history, such as the
erroneous portrayal of Neanderthals as stooping halfwits, and the demise of the
embarrassing 1960s notion of “Man the Hunter”, which has been superseded by a
model that stresses female gathering skills and scavenging. This helps Lewin to
point to frailties in today’s models, such as possible distortions caused by the
European bias in the archaeology of the past 250 000 years.

The blurb on the back cover stresses the book’s “ecological” approach, as if
this was a matter of choice. But Lewin’s highly condensed survey makes it plain
that in the past 20 years, new theories have increasingly had to satisfy
ecological tests, such as their implications for energy use, reproductive rates
or the ability to cope with seasonal changes in resources.

Speculation about the origins of bipedalism, for instance, must nowadays deal
with questions about the physiology of heat loss and the energy advantage of
walking between dispersed food resources. Archaeologists also measure
experimentally how much flesh can be cut with various stone tools.

An alternative approach might be based on sociobiology and game theory. But
despite such theories’ popularity with the press, they have proved tantalisingly
difficult to demonstrate in primate field studies. And speculation about our
past social organisation based on that of our closest primate cousins is
complicated by the wide range of social structures found among apes.

If there is a weakness in the book, it is its tinge of conservatism. For
example, Lewin has studiously avoided “fringe issues”. But any serious student
will soon enough stumble across the feminist-inspired work on women and children
in evolution, the aquatic ape hypothesis or the “sex strike” theory.

Failure to mention at least some of this work tends to reinforce the view of
students that there is a conspiracy at work. Many professionals accept that
however wacky they think these theories are, discussion often opens up new
avenues of study and teaches their students how to weigh up evidence.

Another curious omission is the very limited reference to the anthropological
fieldwork on hunter-gatherer societies collected in the past
century—studies which will soon be our only source of documentary
information on a nonagricultural way of life. If these omissions are the
responsibility of overcautious editors, they have done Lewin a disservice.

And, while the book is bulky, it’s a shame that its price is likely to hurt
student pockets.

It took the influence of feminism in the 1970s to puncture the “Man the
Hunter” concept of early humanity, as Hager’s contributors describe. Before
then, hunting, the tools it required and the copious meat it was assumed to have
delivered were considered not only pivotal but utterly masculine.

Superior field methods, and a more critical approach, now suggest that
meat-eating and the use of stone tools probably arose when early humans
scavenged the kills of big cats for bone marrow. Organised hunting came later,
and probably only rarely provided the bulk of the diet.

So early division of labour around hunting seems much less certain. Gilda
Morelli’s study of the limited sexual division of labour among today’s young Efe
foragers in central Africa, in The Evolving Female, neatly underlines
this point.

And if getting meat required no hunting, what is to have prevented females
from acquiring both the taste for flesh and tools to satisfy it? Fire, language,
and symbolism, once tacitly assumed to be somehow linked to hunting, make just
as much sense as female inspirations—as these two books assert.

Both of these books may mark something of a turning point in palaeoanthropology. They
deserve to appear quickly in university libraries and lecture notes.

The unfortunately titled Evolution of Social Behaviour Patterns in
Primates and Man (edited by W. G. Runciman, John Maynard Smith and Robin
Dunbar, Oxford University Press, £25, ISBN 0197261647) gives a good
selection of the clever but rather uncoordinated theories that still dominate
the mainstream. Among these papers from a 1995 conference, those which stand out
are Robert Foley on the role of ecology, Steven Mithen on ancient consciousness,
Leslie Aiello on bipedalism and language, and Christophe Boesch on chimpanzee
culture.

The focus on adult social organisation in evolutionary studies may be
something of an artefact. Primates are long-lived, and field trips short. So
there are many “cross-sectional” studies on, say, relations between the sexes in
a large group over a short period; and little of the “longitudinal” work needed
to elucidate relations between generations—the real grist of
evolution.

Long-term studies are now, however, beginning to yield results. It seems that
the effect of individuals’ current social status on the reproductive success of
their descendants is complex, and highly variable between species. In animals
with long periods of dependency, we may eventually find simpler answers by
looking at parental care as an factor influencing subsequent reproductive
success.

The weighty Parental Care (edited by Jay Rosenblatt and Charles
Snowdon, Academic Press, £75/$99, ISBN 0120045257) covers
invertebrates through to primates, and is a welcome update in this difficult
field. There is much physiology and behaviour, and an intriguing theme which
examines links between embryology, physiology and parental activity. But
evolutionary context is largely missing—evidence that this fascinating
field is still at an early stage.

This constraint is no barrier to the delightful A Natural History of
Parenting by Susan Allport (Harmony, $23, ISBN 0517707993).
Observant and witty, Allport is a science writer, sheep breeder, keen naturalist
and mother of two. She draws on all this experience to speculate, for instance,
about the dawning sense of parental responsibility, anxiety and joy that must
have livened up the long haul through the lower Stone Age.

Her thoughtful remarks on this topic will possibly appear naively unguarded
to some academic readers. And there are some anachronisms in the biology too,
such as Allport’s certainty that birds can’t smell. But this is good popular
writing with some valuable ideas that deserve academic attention.

Let’s hope professionals of both sexes will soon be pursuing the subject of
parenting in the Palaeolithic. And I look forward to reading these authors on a
topic that might treat the achievements of both sexes more dispassionately
still—the child as an active agent in evolution.

Fortey made his claim in Cardiff at last month’s regional conference
of the Linnean Society of London. He is working with Derek Briggs of the
University of Bristol, a researcher who was part of a team which recently
re-examined the Burgess Shale fauna. The deposit also includes other strange
animals, which Stephen Jay Gould of Harvard University and others have claimed
are extinct phyla.

The Cambrian fossil arthropods are marine animals, most of which are
only a few centimetres long. They include Marrella, which has a head shield
bearing two pairs of spines; Sidneyla, which has a wide blunt head, a carapace
over several pairs of legs, and a tail; and, possibly, Anomolacaris, which
has a circular mouth and two feeding appendages.

The exotic range of types has led some researchers to suggest that the
differences existing between the Burgess Shale forms are as great as those
which now distinguish the major groups of arthropods from one another.
They have claimed that a special evolutionary mechanism was operating during
the Cambrian period.

Fortey and Briggs tested this theory using three separate methods to
compare 22 different types of fossil arthropods with 11 specimens representative
of modern arthropods. The results suggest that the bizarre appearance of
many of the fossil arthropods from the Burgess Shale obscures underlying
similarities which they share with each other and with modern arthropods.
Equally, the unique differences of each of the fossil types, while startling
to the modern eye, are no more numerous than the unique differences of modern
arthropods.

The researchers have carried out a multi-dimensional analysis of the
shapes of the fossil types. This suggests that they are less disparate in
form than the modern representatives examined.

Fortey believes that the Cambrian arthropod fauna have a strange appearance
because they represent arthropods that are ‘in the process of assembly’
– transitional forms which have not acquired the appendages found later.
‘It seems as if presumptions about the differences displayed by the Burgess
Shale-type fauna have led to overestimates of their uniqueness in the evolutionary
history of arthropods,’ says Fortey.

Referring to the non-arthropod Cambrian specimens as well, Fortey says:
‘This suggests that the existence of large numbers of other, extinct, invertebrate
‘phyla’ at this time should be questioned.’

The process has already begun, with a new analysis placing the apparently
mysterious Burgess Shale creature Hallucigenia into a modern group with
other living velvet worms (Nature, vol 351, p 225).

Fortey is also sceptical of speculation that unique evolutionary mechanisms
were needed to provide several phyla in the period following the ‘Cambrian
explosion’ – the sudden appearance at about 570 million years ago of animals
clearly related to forms that are still living. He suspects that types ancestral
to the Burgess Shale-type fauna are still to be found.

Gould, who was at the conference, said that he could not agree with
Fortey’s conclusions. He told ��è����Ƶ that the claims of Fortey and
Briggs would be refuted by an article of his soon to appear in the journal
Paleobiology.