This month's National Geographic has a very interesting article about the
other humans who lived upon our planet, The Neanderthals. We know so
little about the development of our species. Searching for information on
it, will bring you many theories. Most agree though, that the human
species, in one form or another have been around for a couple million
years... Yet we have so little information on their evolutionary process
to modern day man. Reading this very interesting article will make you
acknowledge how vulnerable life is. So many species have come and gone and
we have barely scratched the surface of realizing their existence. Perhaps
we will never learn completely how life formed upon our planet and how we
got to where we are today, but there's one fact for sure; Science will
endure and will never give up its quest to bring us answers. National
Geographic is a good way to keep up with new scientific discovery.
http://thinkingblue.blogspot.com
Eurasia was theirs alone for 200,000 years.
Then the newcomers arrived.
By Stephen S. Hall
Reconstruction by Kennis & Kennis/Photograph by Joe McNally
In March of 1994 some spelunkers exploring an extensive cave system in northern
Spain
poked their lights into a small side gallery and noticed two human mandibles
jutting out of the
sandy soil. The cave, called El Sidrón, lay in the midst of a remote upland
forest of chestnut
and oak trees in the province of Asturias, just south of the Bay of Biscay.
Suspecting that the
jawbones might date back as far as the Spanish Civil War, when Republican
partisans used El
Sidrón to hide from Franco's soldiers, the cavers immediately notified the local
Guardia Civil.
But when police investigators inspected the gallery, they discovered the remains of a much
larger—and, it would turn out, much older—tragedy.
Within days, law enforcement officials had shoveled out some 140 bones, and a
local judge
ordered the remains sent to the national forensic pathology institute in Madrid.
By the time
scientists finished their analysis (it took the better part of six years), Spain
had its earliest
cold case. The bones from El Sidrón were not Republican soldiers, but the
fossilized remains
of a group of Neanderthals who lived, and perhaps died violently, approximately
43,000 years
ago. The locale places them at one of the most important geographical
intersections of
prehistory, and the date puts them squarely at the center of one of the most
enduring
mysteries in all of human evolution.
The Neanderthals, our closest prehistoric relatives, dominated Eurasia for the
better part of
200,000 years. During that time, they poked their famously large and protruding
noses into
every corner of Europe, and beyond—south along the Mediterranean from the Strait
of Gibraltar
to Greece and Iraq, north to Russia, as far west as Britain, and almost to
Mongolia in the east.
Scientists estimate that even at the height of the Neanderthal occupation of
western Europe,
their total number probably never exceeded 15,000. Yet they managed to endure,
even when a
cooling climate turned much of their territory into something like northern
Scandinavia today—a
frigid, barren tundra, its bleak horizon broken by a few scraggly trees and just
enough lichen
to keep the reindeer happy.
By the time of the tragedy at El Sidrón, however, the Neanderthals were on the
run, seemingly
pinned down in Iberia, pockets of central Europe, and along the southern
Mediterranean by a
deteriorating climate, and further squeezed by the westward spread of
anatomically modern
humans as they emerged from Africa into the Middle East and beyond. Within
another 15,000
years or so, the Neanderthals were gone forever, leaving behind a few bones and
a lot of
questions. Were they a clever and perseverant breed of survivors, much like us,
or a
cognitively challenged dead end? What happened during that period, roughly
45,000 to 30,000
years ago, when the Neanderthals shared some parts of the Eurasian landscape
with those
modern human migrants from Africa? Why did one kind of human being survive, and
the other
disappear?
On a damp, fog-shrouded morning in September 2007, I stood before the entrance
to El Sidrón
with Antonio Rosas of the National Museum of Natural Sciences in Madrid, who
heads the
paleoanthropological investigation. One of his colleagues handed me a
flashlight, and I
gingerly lowered myself into the black hole. As my eyes adjusted to the
interior, I began to
make out the fantastic contours of a karstic cave. An underground river had
hollowed out a
deep vein of sandstone, leaving behind a limestone cavern extending hundreds of
yards, with
side galleries spidering out to at least 12 entrances. Ten minutes into the
cave, I arrived at the
Galería del Osario—the "tunnel of bones." Since 2000, some 1,500 bone fragments
have been
unearthed from this side gallery, representing the remains of at least nine
Neanderthals—five
young adults, two adolescents, a child of about eight, and a three-year-old
toddler. All showed
signs of nutritional stress in their teeth—not unusual in young Neanderthals
late in their time on
Earth. But a deeper desperation is etched in their bones. Rosas picked up a
recently
unearthed fragment of a skull and another of a long bone of an arm, both with
jagged edges.
"These fractures were—clop—made by humans," Rosas said, imitating the blow of a
stone tool.
"It means these fellows went after the brains and into long bones for the
marrow."
In addition to the fractures, cut marks left on the bones by stone tools clearly
indicate that the
individuals were cannibalized. Whoever ate their flesh, and for whatever
reason—starvation?
ritual?—the subsequent fate of their remains bestowed upon them a distinct and
marvelous kind
of immortality. Shortly after the nine individuals died—possibly within days—the
ground below
them suddenly collapsed, leaving little time for hyenas and other scavengers to
scatter the
remains. A slurry of bones, sediment, and rocks tumbled 60 feet into a hollow
limestone
chamber below, much as mud fills the inside walls of a house during a flood.
There, buffered by sand and clay, preserved by the cave's constant temperature,
and
sequestered in their jewel cases of mineralized bone, a few precious molecules
of the
Neanderthals' genetic code survived, awaiting a time in the distant future when
they could be
plucked out, pieced together, and examined for clues to how these people lived,
and why they
vanished.
The first clue that our kind of human was not the first to inhabit Europe turned
up a century and
a half ago, about eight miles east of Düsseldorf, Germany. In August 1856
laborers quarrying
limestone from a cave in the Neander Valley dug out a beetle-browed skullcap and
some thick
limb bones. Right from the start, the Neanderthals were saddled with an enduring
cultural
stereotype as dim-witted, brutish cavemen. The size and shape of the fossils
does suggest a
short, stout fireplug of a physique (males averaged about five feet, five inches
tall and about
185 pounds), with massive muscles and a flaring rib cage presumably encasing
capacious
lungs. Steven E. Churchill, apaleoanthropologist at Duke University, has
calculated that to
support his body mass in a cold climate, a typical Neanderthal male would have
needed up to
5,000 calories daily, or approaching what a bicyclist burns each day in the Tour
de France. Yet
behind its bulging browridges, a Neanderthal's low-domed skull housed a brain
with a volume
slightly larger on average than our own today. And while their tools and weapons
were more
primitive than those of the modern humans who supplanted them in Europe, they
were no less
sophisticated than the implements made by their modern human contemporaries
living in
Africa and the Middle East.
One of the longest and most heated controversies in human evolution rages around
the
genetic relationship between Neanderthals and their European successors. Did the
modern
humans sweeping out of Africa beginning some 60,000 years ago completely replace
the
Neanderthals, or did they interbreed with them? In 1997 the latter hypothesis
was dealt a
powerful blow by geneticist Svante Pääbo—then at the University of Munich—who used an arm
bone from the original Neanderthal man to deliver it. Pääbo and his colleagues
were able to
extract a tiny 378-letter snippet of mitochondrial DNA (a kind of short genetic
appendix to the
main text in each cell) from the 40,000-year-old specimen. When they read out
the letters of the code, they found that the specimen's DNA differed from living
humans to a degree suggesting that the Neanderthal and modern human lineages had
begun to diverge long
before the modern human migration out of Africa. Thus the two represent separate
geographic
and evolutionary branches splitting from a common ancestor. "North of the
Mediterranean, this
lineage became Neanderthals," said Chris Stringer, research leader on human
origins at the
Natural History Museum in London, "and south of the Mediterranean, it became
us." If there
was any interbreeding when they encountered each other later, it was too rare to
leave a trace
of Neanderthal mitochondrial DNA in the cells of living people.
Pääbo's genetic bombshell seemed to confirm that Neanderthals were a separate
species—but
it does nothing to solve the mystery of why they vanished, and our species
survived.
One obvious possibility is that modern humans were simply more clever, more
sophisticated,
more "human." Until recently, archaeologists pointed to a "great leap forward"
around 40,000
years ago in Europe, when the Neanderthals' relatively humdrum stone tool
industry—called
Mousterian, after the site of Le Moustier in southwestern France—gave way to the
more varied
stone and bone tool kits, body ornaments, and other signs of symbolic expression
associated
with the appearance of modern humans. Some scientists, such as Stanford
University
anthropologist Richard Klein, still argue for some dramatic genetic change in
the
brain—possibly associated with a development in language—that propelled early
modern
humans to cultural dominance at the expense of their beetle-browed forebears.
But the evidence in the ground is not so cut and dried. In 1979 archaeologists
discovered a
late Neanderthal skeleton at Saint-Césaire in southwestern France surrounded not
with typical
Mousterian implements, but with a surprisingly modern repertoire of tools. In
1996
Jean-Jacques Hublin of the Max Planck Institute in Leipzig and Fred Spoor of
University
College London identified a Neanderthal bone in another French cave, near
Arcy-sur-Cure, in a
layer of sediment also containing ornamental objects previously associated only
with modern
humans, such as pierced animal teeth and ivory rings. Some scientists, such as
British
paleoanthropologist Paul Mellars, dismiss such modern "accessorizing" of a
fundamentally
archaic lifestyle as an "improbable coincidence"—a last gasp of imitative
behavior by
Neanderthals before the inventive newcomers out of Africa replaced them. But
more recently,
Francesco d'Errico of the University of Bordeaux and Marie Soressi, also at the
Max Planck
Institute in Leipzig, analyzed hundreds of crayon-like blocks of manganese
dioxide from a
French cave called Pech de l'Azé, where Neanderthals lived well before modern
humans
arrived in Europe. D'Errico and Soressi argue that the Neanderthals used the
black pigment
for body decoration, demonstrating that they were fully capable of achieving
"behavioral
modernity" all on their own.
"At the time of the biological transition," says Erik Trinkaus, a
paleoanthropologist at
Washington University in St. Louis, "the basic behavior [of the two groups] is
pretty much the
same, and any differences are likely to have been subtle." Trinkaus believes
they indeed may
have mated occasionally. He sees evidence of admixture between Neanderthals and
modern
humans in certain fossils, such as a 24,500-year-old skeleton of a young child
discovered at
the Portuguese site of Lagar Velho, and a 32,000-year-old skull from a cave
called Muierii in
Romania. "There were very few people on the landscape, and you need to find a
mate and
reproduce," says Trinkaus. "Why not? Humans are not known to be choosy. Sex
happens."
It may have happened, other researchers say, but not often, and not in a way
that left behind
any evidence. Katerina Harvati, another researcher at the Max Planck Institute
in Leipzig, has
used detailed 3-D measurements of Neanderthal and early modern human fossils to
predict
exactly what hybrids between the two would have looked like. None of the fossils
examined so
far matches her predictions.
The disagreement between Trinkaus and Harvati is hardly the first time that two
respected
paleoanthropologists have looked at the same set of bones and come up with
mutually
contradictory interpretations. Pondering—and debating—the meaning of fossil
anatomy will
always play a role in understanding Neanderthals. But now there are other ways
to bring them
back to life.
Two days after my first descent into El Sidrón cave, Araceli Soto Flórez, a
graduate student at
the University of Oviedo, came across a fresh Neanderthal bone, probably a
fragment of a
femur. All digging immediately ceased, and most of the crew evacuated the
chamber. Soto
Flórez then squeezed herself into a sterile jumpsuit, gloves, booties, and
plastic face mask.
Under the watchful eyes of Antonio Rosas and molecular biologist Carles Lalueza-Fox,
she
delicately extracted the bone from the soil, placed it in a sterile plastic bag,
and deposited the
bag in a chest of ice. After a brief stop in a hotel freezer in nearby Villamayo,
the leg bone
eventually arrived at Lalueza-Fox's laboratory at the Institute of Evolutionary
Biology in
Barcelona. His interest was not in the anatomy of the leg or anything it might
reveal about
Neanderthal locomotion. All he wanted from it was its DNA.
Prehistoric cannibalism has been very good for modern-day molecular biology.
Scraping flesh
from a bone also removes the DNA of microorganisms that might otherwise
contaminate the
sample. The bones of El Sidrón have not yielded the most DNA of any Neanderthal
fossil—that
honor belongs to a specimen from Croatia, also cannibalized—but so far they have
revealed the
most compelling insights into Neanderthal appearance and behavior. In October
2007
Lalueza-Fox, Holger Römpler of the University of Leipzig, and their colleagues
announced that
they had isolated a pigmentation gene from the DNA of an individual at El Sidrón
(as well as
another Neanderthal fossil from Italy). The particular form of the gene, called
MC1R, indicated
that at least some Neanderthals would have had red hair, pale skin, and,
possibly, freckles.
The gene is unlike that of red-haired people today, however—suggesting that
Neanderthals and
modern humans developed the trait independently, perhaps under similar pressures
in
northern latitudes to evolve fair skin to let in more sunlight for the
manufacture of vitamin D.
Just a few weeks earlier, Svante Pääbo, who now heads the genetics laboratory at
the Max
Planck Institute in Leipzig, Lalueza-Fox, and their colleagues had announced an
even more
astonishing find: Two El Sidrón individuals appeared to share, with modern
humans, a version
of a gene called FOXP2 that contributes to speech and language ability, acting
not only in the
brain but also on the nerves that control facial muscles. Whether Neanderthals
were capable
of sophisticated language abilities or a more primitive form of vocal
communication (singing,
for example) still remains unclear, but the new genetic findings suggest they
possessed some
of the same vocalizing hardware as modern humans.
All this from a group of ill-fated Neanderthals buried in a cave collapse, soon
after they were
consumed by their own kind.
"So maybe it's a good thing to eat your conspecifics," says Pääbo.
A tall, cheerful Swede, Pääbo is the main engine behind a breathtaking
scientific tour de force:
the attempt, expected to be completed next month, to read out not just single
Neanderthal
genes, but the entire three-billion-letter sequence of the Neanderthal genome.
Traces of DNA
in fossils are vanishingly faint, and because Neanderthal DNA is ever so close
to that of living
people, one of the biggest hurdles in sequencing it is the ever present threat
of contamination
by modern human DNA—especially by the scientists handling the specimens. The
precautions
taken in excavating at El Sidrón are now becoming standard practice at other
Neanderthal
sites. Most of the DNA for Pääbo's genome project, however, has come from the
Croatian
specimen, a 38,000-year-old fragment of leg bone found almost 30 years ago in
the Vindija
cave. Originally deemed unimportant, it sat in a drawer in Zagreb, largely
untouched and thus
uncontaminated, for most of its museum life.
Now it is the equivalent of a gold mine for prehistoric human DNA, albeit an
extremely difficult
mine to work. After the DNA is extracted in a sterile laboratory in the basement
of the Max
Planck Institute, it is shipped overnight to Branford, Connecticut, where
collaborators at 454
Life Sciences have invented machines that can rapidly decipher the sequence of
DNA's
chemical letters. The vast majority of those letters spell out bacterial
contaminants or other
non-Neanderthal genetic information. But in the fall of 2006, Pääbo and his
colleagues
announced they had deciphered approximately one million letters of Neanderthal
DNA. (At the
same time, a second group, headed by Edward Rubin at the Department of Energy
Joint
Genome Institute in Walnut Creek, California, used DNA provided by Pääbo to read
out
snippets of genetic code using a different approach.) By last year, dogged by
claims that their
work had serious contamination problems, the Leipzig group claimed to have
improved
accuracy and identified about 70 million letters of DNA—roughly 2 percent of the
total.
"We know that the human and chimpanzee sequences are 98.7 percent the same, and
Neanderthals are much closer to us than chimps," said Ed Green, head of
biomathematics in
Pääbo's group in Leipzig, "so the reality is that for most of the sequence,
there's no difference
between Neanderthals and [modern] humans." But the differences—less than a half
percent of
the sequence—are enough to confirm that the two lineages had begun to diverge
around
700,000 years ago. The Leipzig group also managed to extract mitochondrial DNA
from two
fossils of uncertain origin that had been excavated in Uzbekistan and southern
Siberia; both
had a uniquely Neanderthal genetic signature. While the Uzbekistan specimen, a
young boy,
had long been considered a Neanderthal, the Siberian specimen was a huge
surprise,
extending the known Neanderthal range some 1,200 miles east of their European
stronghold.
So, while the new genetic evidence appears to confirm that Neanderthals were a
separate
species from us, it also suggests that they may have possessed human language
and were
successful over a far larger sweep of Eurasia than previously thought. Which
brings us back
to the same hauntingly persistent question that has shadowed them from the
beginning: Why
did they disappear?
To coax a Neanderthal fossil to reveal its secrets, you can measure it with
calipers, probe it
with a CT scan, or try to capture the ghost of its genetic code. Or if you
happen to have at your
disposal a type of particle accelerator called a synchrotron, you can put it in
a lead-lined room
and blast it with a 50,000-volt x-ray beam, without disturbing so much as a
single molecule.
Over a sleep-deprived week in October 2007, a team of scientists gathered at the
European
Synchrotron Radiation Facility (ESRF) in Grenoble, France, for an unprecedented
"convention
of jawbones." The goal was to explore a crucial question in the life history of
the
Neanderthals: Did they reach maturity at an earlier age than their modern human
counterparts? If so, it might have implications for their brain development,
which in turn might
help explain why they disappeared. The place to look for answers was deep inside
the
structure of Neanderthal teeth.
"When I was young, I thought that teeth were not so useful in assessing recent
human
evolution, but now I think they are the most important thing," said Jean-Jacques
Hublin, who
had accompanied his Max Planck Institute colleague Tanya Smith to Grenoble.
Along with Paul Tafforeau of the ESRF, Hublin and Smith were squeezed into a
computer-filled
hutch at the facility—one of the three largest synchrotrons in the world, with a
storage ring for
energized electrons half a mile in circumference—watching on a video monitor as
the x-ray
beam zipped through the right upper canine of an adolescent Neanderthal from the
site of Le
Moustier in southwestern France, creating arguably the most detailed dental
x-ray in human
history. Meanwhile, a dream team of other fossils sat on a shelf nearby,
awaiting their turn in
the synchrotron's spotlight: two jawbones of Neanderthal juveniles recovered in
Krapina,
Croatia, dating back 130,000 to 120,000 years; the so-called La Quina skull from
a
Neanderthal youth, discovered in France and dating from between 75,000 to 40,000
years ago;
and two striking 90,000-year-old modern human specimens, teeth intact, found in
a rock
shelter called Qafzeh in Israel.
When teeth are imaged at high resolution, they reveal a complex,
three-dimensional hatch of
daily and longer periodic growth lines, like tree rings, along with stress lines
that encode key
moments in an individual's life history. The trauma of birth etches a sharp
neonatal stress line
on the enamel; the time of weaning and episodes of nutritional deprivation or
other
environmental stresses similarly leave distinct marks on developing teeth.
"Teeth preserve a
continuous, permanent record of growth, from before birth until they finish
growing at the end
of adolescence," Smith explained. Human beings take longer to reach puberty than
chimpanzees, our nearest living relatives—which means more time spent learning
and
developing within the context of the social group. Early hominin species that
lived on the
savanna in Africa millions of years ago matured fast, more like chimps. So when
in evolution
did the longer modern pattern begin?
--
To address this question, Smith, Tafforeau, and colleagues had previously used
the
synchrotron to demonstrate that an early modern human child from a site called
Jebel Irhoud
in Morocco (dated to around 160,000 years ago) showed the modern human life
history
pattern. In contrast, the "growth rings" in the 100,000-year-old tooth of a
young Neanderthal
discovered in the Scladina cave in Belgium indicated that the child was eight
years old when it
died and appeared to be on track to reach puberty several years sooner than the
average for
modern humans. Another research team, using a single Neanderthal tooth, had
found no such
difference between its growth pattern and that of living humans. But while a
full analysis from
the "jawbone convention" would take time, preliminary results, Smith said, were
"consistent
with what we see in Scladina."
"This would certainly affect Neanderthal social organization, mating strategy,
and parenting
behavior," says Hublin. "Imagine a society where individuals start to reproduce
four years
earlier than in modern humans. It's a very different society. It could also mean
the
Neanderthals' cognitive abilities may have been different from modern humans'."
Neanderthal society may have differed in another way crucial to group survival:
what
archaeologists call cultural buffering. A buffer is something in a group's
behavior—a
technology, a form of social organization, a cultural tradition—that hedges its
bets in the
high-stakes game of natural selection. It's like having a small cache of extra
chips at your
elbow in a poker game, so you don't have to fold your hand quite as soon. For
example, Mary
Stiner and Steven Kuhn of the University of Arizona argue that early modern
humans emerged
from Africa with the buffer of an economically efficient approach to hunting and
gathering that
resulted in a more diverse diet. While men chased after large animals, women and
children
foraged for small game and plant foods. Stiner and Kuhn maintain that
Neanderthals did not
enjoy the benefits of such a marked division of labor. From southern Israel to
northern
Germany, the archaeological record shows that Neanderthals instead relied almost
entirely on
hunting big and medium-size mammals like horses, deer, bison, and wild cattle.
No doubt they
were eating some vegetable material and even shellfish near the Mediterranean,
but the lack
of milling stones or other evidence for processing plant foods suggests to
Stiner and Kuhn
that to a Neanderthal vegetables were supplementary foods, "more like salads,
snacks, and
desserts than energy-rich staple foods."
Their bodies' relentless demand for calories, especially in higher latitudes and
during colder
interludes, probably forced Neanderthal women and children to join in the hunt—a
"rough and
dangerous business," write Stiner and Kuhn, judging by the many healed fractures
evident on
Neanderthal upper limbs and skulls. The modern human bands that arrived on the
landscape
toward the end of the Neanderthals' time had other options.
"By diversifying diet and having personnel who [did different tasks], you have a
formula for
spreading risk, and that is ultimately good news for pregnant women and for
kids," Stiner told
me. "So if one thing falls through, there's something else." A Neanderthal woman
would have
been powerful and resilient. But without such cultural buffering, she and her
young would have
been at a disadvantage.
Of all possible cultural buffers, perhaps the most important was the cushion of
society itself.
According to Erik Trinkaus, a Neanderthal social unit would have been about the
size of an
extended family. But in early modern human sites in Europe, Trinkaus said, "we
start getting
sites that represent larger populations." Simply living in a larger group has
biological as well
as social repercussions. Larger groups inevitably demand more social
interactions, which
goads the brain into greater activity during childhood and adolescence, creates
pressure to
increase the sophistication of language, and indirectly increases the average
life span of
group members. Longevity, in turn, increases intergenerational transmission of
knowledge
and creates what Chris Stringer calls a "culture of innovation"—the passage of
practical
survival skills and toolmaking technology from one generation to the next, and
later between
one group and another.
Whatever the suite of cultural buffers, they may well have provided an extra,
albeit thin, layer
of insulation against the harsh climatic stresses that Stringer argues peaked
right around the
time the Neanderthals vanished. Ice core data suggest that from about 30,000
years ago until
the last glacial maximum about 18,000 years ago, the Earth's climate fluctuated
wildly,
sometimes within the space of decades. A few more people in the social unit,
with a few more
skills, might have given modern humans an edge when conditions turned harsh.
"Not a vast
edge," Stringer said. "Neanderthals were obviously well adapted to a colder
climate. But with
the superimposition of these extreme changes in climate on the competition with
modern
humans, I think that made the difference."
Which leaves the final, delicate—and, as Jean-Jacques Hublin likes to say,
politically
incorrect—question that has bedeviled Neanderthal studies since the Out of
Africa theory
became generally accepted: Was the replacement by modern humans attenuated and
peaceful, the Pleistocene version of kissing cousins, or was it relatively swift
and hostile?
"Most Neanderthals and modern humans probably lived most of their lives without
seeing
each other," he said, carefully choosing his words. "The way I imagine it is
that occasionally
in these border areas, some of these guys would see each other at a distance…but
I think the
most likely thing is that they excluded each other from the landscape. Not just
avoided, but
excluded. We know from recent research on hunter-gatherers that they are much
less peaceful
than generally believed."
"Sometimes I just turn out the lights in here and think what it must have been
like for them."
Evolutionary biologist Clive Finlayson, of the Gibraltar Museum, was standing in
the vestibule
of Gorham's Cave, a magnificent tabernacle of limestone opening to the sea on
the Rock of
Gibraltar. Inside, fantastic excretions of flowstone drooled from the ceiling of
the massive
nave. The stratigraphy in the cave is pocked with evidence of Neanderthal
occupation going
back 125,000 years, including stone spearpoints and scrapers, charred pine nuts,
and the
remains of ancient hearths. Two years ago, Finlayson and his colleagues used
radiocarbon
dating to determine that the embers in some of those fireplaces died out only
28,000 years
ago—the last known trace of Neanderthals on Earth. (Other hearths in the cave
may be as
young as 24,000 years old, but their dating is controversial.)
From pollen and animal remains, Finlayson has reconstructed what the environment
was like
from 50,000 to 30,000 years ago. Back then, a narrow coastal shelf surrounded
Gibraltar, the
Mediterranean two or three miles distant. The landscape was scrub savanna
scented with
rosemary and thyme, its rolling sand dunes interrupted by the occasional cork
oak and stone
pine, with wild asparagus growing in the coastal flats. Prehistoric vultures,
some with nine-foot
wingspans, nested high up in the cliff face, scanning the dunes for meals.
Finlayson imagines
the Neanderthals watching the birds circle and descend, then racing them for
food. Their diet
was certainly more varied than the typical Neanderthal dependence on terrestrial
game. His
research team has found rabbit bones, tortoise shells, and mussels in the cave,
along with
dolphin bones and a seal skeleton with cut marks. "Except for rice, you've
almost got a
Mousterian paella!" Finlayson joked.
But then things changed. When the coldest fingers of the Ice Age finally reached
southern
Iberia in a series of abrupt fluctuations between 30,000 and 23,000 years ago,
the landscape
was transformed into a semiarid steppe. On this more open playing field, perhaps
the tall,
gracile modern humans moving into the region with projectile spears gained the
advantage
over the stumpy, muscle-bound Neanderthals. But Finlayson argues that it was not
so much
the arrival of modern humans as the dramatic shifts in climate that pushed the
Iberian
Neanderthals to the brink. "A three-year period of intense cold, or a landslide,
when you're
down to ten people, could be enough," he said. "Once you reach a certain level,
you're the
living dead."
The larger point may be that the demise of the Neanderthals is not a sprawling
yet coherent
paleoanthropological novel; rather, it is a collection of related, but unique,
short stories of
extinction. "Why did the Neanderthals disappear in Mongolia?" Stringer asked.
"Why did they
disappear in Israel? Why did they disappear in Italy, in Gibraltar, in Britain?
Well, the answer
could be different in different places, because it probably happened at
different times. So
we're talking about a large range, and a disappearance and retreat at different
times, with
pockets of Neanderthals no doubt surviving in different places at different
times. Gibraltar is
certainly one of their last outposts. It could be the last, but we don't know
for sure."
Whatever happened, the denouement of all these stories had a signatory in
Gorham's Cave.
In a deep recess of the cavern, not far from that last Neanderthal hearth,
Finlayson's team
recently discovered several red handprints on the wall, a sign that modern
humans had
arrived in Gibraltar. Preliminary analysis of the pigments dates the handprints
between 20,300
and 19,500 years ago. "It's like they were saying, Hey, it's a new world now,"
said Finlayson.j
The discovery of the Neanderthal Man, originally believed to be a possible
ancestor of Homo Sapiens. DNA testing showed that they were in fact a seperate
species from us, one who shared a common ancestor with a Hominid who lived in
Africa some 500,000 years ago.
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