Collapse: How Societies Choose to Fail or Succeed (32 page)

play a major role in water cycling, such that massive deforestation tends to
result in lowered rainfall.

Hundreds of skeletons recovered from Copan archaeological sites have
been studied for signs of disease and malnutrition, such as porous bones
and stress lines in the teeth. These skeletal signs show that the health of
Copan's inhabitants deteriorated from
a.d.
650 to 850, both among the elite
and among the commoners, although the health of commoners was worse.

Recall that Copan's population was increasing steeply while the hills
were being occupied. The subsequent abandonment of all of those fields in the hills meant that the burden of feeding the extra population formerly dependent on the hills now fell increasingly on the valley floor, and that more
and more people were competing for the food grown on those 10 square miles of valley bottomland. That would have led to fighting among the farmers themselves for the best land, or for any land, just as in modern
Rwanda (Chapter 10). Because Copan's king was failing to deliver on his
promises of rain and prosperity in return for the power and luxuries that he
claimed, he would have been the scapegoat for this agricultural failure. That may explain why the last that we hear from any Copan king is
a.d.
822 (that
last Long Count date at Copan), and why the royal palace was burned
around
a.d.
850. However, the continued production of some luxury goods
suggest that some nobles managed to carry on with their lifestyle after the
king's downfall, until around
a.d.
975.

To judge from datable pieces of obsidian, Copan's total population de
creased more gradually than did its signs of kings and nobles. The esti
mated population in the year
a.d.
950 was still around 15,000, or 54% of the
peak population of 27,000. That population continued to dwindle, until
there are no more signs of anyone in the Copan Valley by around
a.d.
1250.
The reappearance of pollen from forest trees thereafter provides indepen
dent evidence that the valley became virtually empty of people, and that the
forests could at last begin to recover.

The general outline of Maya history that I have just related, and the example
of Copan's history in particular, illustrates why we talk about "the Maya col
lapse." But the story grows more complicated, for at least five reasons.

First, there was not only that enormous Classic collapse, but at least two previous smaller collapses at some sites, one around the year
a.d.
150 when
El Mirador and some other Maya cities collapsed (the so-called pre-Classic

collapse), the other (the so-called Maya hiatus) in the late 6th century and
early 7th century, a period when no monuments were erected at the well-
studied site of Tikal. There were also some post-Classic collapses in areas whose populations survived the Classic collapse or increased after it
—such as the fall of Chichen Itza around 1250 and of Mayapan around 1450.

Second, the Classic collapse was obviously not complete, because there
were hundreds of thousands of Maya who met and fought the Spaniards
—
far fewer Maya than during the Classic peak, but still far more people than
in the other ancient societies discussed in detail in this book. Those sur
vivors were concentrated in areas with stable water supplies, especially in
the north with its cenotes, the coastal lowlands with their wells, near a
southern lake, and along rivers and lagoons at lower elevations. However,
population otherwise disappeared almost completely in what previously had been the Maya heartland in the south.

Third, the collapse of population (as gauged by numbers of house sites
and of obsidian tools) was in some cases much slower than the decline in
numbers of Long Count dates, as I already mentioned for Copan. What col
lapsed quickly during the Classic collapse was the institution of kingship
and the Long Count calendar.

Fourth, many apparent collapses of cities were really nothing more than
"power cycling": i.e., particular cities becoming more powerful, then declin
ing or getting conquered, and then rising again and conquering their neigh
bors, without changes in the whole population. For example, in the year 562
Tikal was defeated by its rivals Caracol and Calakmul, and its king was cap
tured and killed. However, Tikal then gradually gained strength again and
finally conquered its rivals in 695, long before Tikal joined many other
Maya cities in the Classic collapse (last dated Tikal monuments
a.d.
869). Similarly, Copan grew in power until the year 738, when its king Waxak-
lahuun Ub'aah K'awil (a name better known to Maya enthusiasts today by its unforgettable translation of "18 Rabbit") was captured and put to death by the rival city of Quirigua, but then Copan thrived during the following
half-century under more fortunate kings.

Finally, cities in different parts of the Maya area rose and fell on different
trajectories. For example, the Puuc region in the northwest Yucatan Penin
sula, after being almost empty of people in the year 700, exploded in population after 750 while the southern cities were collapsing, peaked in population
between 900 and 925, and then collapsed in turn between 950 and 1000.
El Mirador, a huge site in the center of the Maya area with one of the world's

largest pyramids, was settled in 200
b.c.
and abandoned around
a.d.
150, long before the rise of Copan. Chichen Itza in the northern peninsula grew
after
a.d.
850 and was the main northern center around 1000, only to be de
stroyed in a civil war around 1250.

Some archaeologists focus on these five types of complications and
don't want to recognize a Classic Maya collapse at all. But this overlooks the
obvious facts that cry out for explanation: the disappearance of between 90 and 99% of the Maya population after
a.d.
800, especially in the formerly
most densely populated area of the southern lowlands, and the disappear
ance of kings, Long Count calendars, and other complex political and cul
tural institutions. That's why we talk about a Classic Maya collapse, a
collapse both of population and of culture that needs explaining.

Two other phenomena that I have mentioned briefly as contributing to Maya
collapses require more discussion: the roles of warfare and of drought.

Archaeologists for a long time believed the ancient Maya to be gentle
and peaceful people. We now know that Maya warfare was intense, chronic,
and unresolvable, because limitations of food supply and transportation
made it impossible for any Maya principality to unite the whole region in
an empire, in the way that the Aztecs and Incas united Central Mexico and
the Andes, respectively. The archaeological record shows that wars became
more intense and frequent towards the time of the Classic collapse. That
evidence comes from discoveries of several types over the last 55 years: archaeological excavations of massive fortifications surrounding many Maya
sites; vivid depictions of warfare and captives on stone monuments, vases
(Plate 14), and on the famous painted murals discovered in 1946 at Bonam-
pak; and the decipherment of Maya writing, much of which proved to consist of royal inscriptions boasting of conquests. Maya kings fought to take
one another captive, one of the unfortunate losers being Copan's King 18
Rabbit. Captives were tortured in unpleasant ways depicted clearly on the monuments and murals (such as yanking fingers out of sockets, pulling out teeth, cutting off the lower jaw, trimming off the lips and fingertips, pulling
out the fingernails, and driving a pin through the lips), culminating (some
times several years later) in the sacrifice of the captive in other equally un
pleasant ways (such as tying the captive up into a ball by binding the arms and legs together, then rolling the balled-up captive down the steep stone
staircase of a temple).

Maya warfare involved several well-documented types of violence: wars

between separate kingdoms; attempts of cities within a kingdom to secede
by revolting against the capital; and civil wars resulting from frequent vio
lent attempts by would-be kings to usurp the throne. All of these types were
described or depicted on monuments, because they involved kings and no
bles. Not considered worthy of description, but probably even more fre
quent, were fights between commoners over land, as overpopulation became
excessive and as land became scarce.

The other phenomenon important to understanding Maya collapses is
the repeated occurrence of droughts, studied especially by Mark Brenner,
David Hodell, the late Edward Deevey, and their colleagues at the University
of Florida, and discussed in a recent book by Richardson Gill. Cores bored into layers of sediments at the bottoms of Maya lakes yield many measure
ments that let us infer droughts and environmental changes. For example, gypsum (a.k.a. calcium sulfate) precipitates out of solution in a lake into
sediments when lake water becomes concentrated by evaporation during a drought. Water containing the heavy form of oxygen known as the isotope
oxygen-18 also becomes concentrated during droughts, while water con
taining the lighter isotope oxygen-16 evaporates away. Molluscs and Crustacea living in the lake take up oxygen to lay down in their shells, which
remain preserved in the lake sediments, waiting for climatologists to ana
lyze for those oxygen isotopes long after the little animals have died. Radio
carbon dating of a sediment layer identifies the approximate year when the drought or rainfall conditions inferred from those gypsum and oxygen iso
tope measurements were prevailing. The same lake sediment cores provide
palynologists with information about deforestation (which shows up as a
decrease in pollen from forest trees at the expense of an increase in grass pollen), and also soil erosion (which shows up as a thick clay deposit and
minerals from the washed-down soil).

Based on these studies of radiocarbon-dated layers from lake sediment cores, climatologists and paleoecologists conclude that the Maya area was
relatively wet from about 5500
b.c.
until 500
b.c.
The following period from
475 to 250
b.c.,
just before the rise of pre-Classic Maya civilization, was dry.
The pre-Classic rise may have been facilitated by the return of wetter conditions after 250
b.c.,
but then a drought from
a.d.
125 until
a.d.
250 was as
sociated with the pre-Classic collapse at El Mirador and other sites. That
collapse was followed by the resumption of wetter conditions and of the
buildup of Classic Maya cities, temporarily interrupted by a drought
around
a.d.
600 corresponding to a decline at Tikal and some other sites.
Finally, around
a.d.
760 there began the worst drought in the last 7,000

years, peaking around the year
a.d.
800, and suspiciously associated with
the Classic collapse.

Careful analysis of the frequency of droughts in the Maya area shows a
tendency for them to recur at intervals of about 208 years. Those drought
cycles may result from small variations in the sun's radiation, possibly made
more severe in the Maya area as a result of the rainfall gradient in the Yu
catan (drier in the north, wetter in the south) shifting southwards. One
might expect those changes in the sun's radiation to affect not just the Maya region but, to varying degrees, the whole world. In fact, climatologists have
noted that some other famous collapses of prehistoric civilizations far from the Maya realm appear to coincide with the peaks of those drought cycles,
such as the collapse of the world's first empire (the Akkadian Empire of Mesopotamia) around 2170
b.c.,
the collapse of Moche IV civilization on
the Peruvian coast around
a.d.
600, and the collapse of Tiwanaku civiliza
tion in the Andes around
a.d.
1100.

In the most naive form of the hypothesis that drought contributed to
causing the Classic collapse, one could imagine a single drought around
a.d.
800 uniformly affecting the whole realm and triggering the fall of all
Maya centers simultaneously. Actually, as we have seen, the Classic collapse
hit different centers at slightly different times in the period
a.d.
760-910,
while sparing other centers. That fact makes many Maya specialists skeptical
of a role of drought.

But a properly cautious climatologist would not state the drought hy
pothesis in that implausibly oversimplied form. Finer-resolution variation
in rainfall from one year to the next can be calculated from annually banded
sediments that rivers wash into ocean basins near the coast. These yield the
conclusion that "The Drought" around
a.d.
800 actually had four peaks, the
first of them less severe: two dry years around
a.d.
760, then an even drier
decade around
a.d.
810-820, three drier years around
a.d.
860, and six drier
years around
a.d.
910. Interestingly, Richardson Gill concluded, from the
latest dates on stone monuments at various large Maya centers, that collapse dates vary among sites and fall into three clusters: around
a.d.
810, 860, and
910, in agreement with the dates for the three most severe droughts. It
would not be at all surprising if a drought in any given year varied locally in
its severity, hence if a series of droughts caused different Maya centers to
collapse in different years, while sparing centers with reliable water supplies
such as cenotes, wells, and lakes.