[Paleopsych] Natural History Magazine: Natural Selections

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Natural Selections
http://www.naturalhistorymag.com/0504/0504_selections.html
2004 May (note date)

R E V I E W

Brains and the Beast

Can the behaviorist's insistence on distinguishing animal from
human cognition be reconciled with evolutionary continuity?
By Frans B. M. de Waal

Do Animals Think?
by Clive D.L. Wynne
Princeton University Press, 2004; $26.95

Intelligence of Apes
and Other Rational Beings
by Duane M. Rumbaugh and David A. Washburn
Yale University Press, 2003; $35.00

IF YOUR DOG DROPS A TENNIS BALL in front of you and looks up at you with tail
wagging, do you figure she wants to play? How naive! Who says dogs have desires
and intentions? Her behavior is merely the product of reinforcement: she has 
been
rewarded for it in the past.

Many scientists have grown up with the so-called law of effect, the idea that 
all
behavior is conditioned by reward and punishment. This principle of learning 
was
advocated by a dominant school of twentieth-century psychological thought known
as American behaviorism. The school's founders, John B. Watson and B.F. 
Skinner,
were happy to explain all conceivable behavior within the narrow confines of 
what
Skinner called "operant conditioning." The mind, if such a thing even existed,
remained a black box. In the early days, the behaviorists applied their 
doctrine
in equal measure to people and other animals. Watson, for instance, to
demonstrate the power of his methods, intentionally created a phobia for furry
objects in a human baby. Initially "little Albert" was unafraid of a tame white
rat. But after Watson paired each appearance of the rat with sharp noises right
behind poor Albert's head, fear of rats was the inevitable outcome. Even human
speech was thought to be the product of simple reinforcement learning.

The behaviorists' goal of unifying the science of behavior was a noble one--but
alas, outside academia the masses resisted. They stubbornly refused to accept
that their own behavior could be explained without considering thoughts,
feelings, and intentions. Don't we all have mental lives, don't we look into 
the
future, aren't we rational beings? Eventually, the behaviorists caved in and
exempted the bipedal ape from their theory of everything.

That was the beginning of the problem for other animals. Once cognitive
complexity was admitted in people, the rest of the animal kingdom became the 
sole
standard-bearer of behaviorism. Animals were expected to follow the law of 
effect
to the letter, and anyone who thought differently was just being 
anthropomorphic.
>From a unified science, behaviorism had become a dichotomous one, with two
separate languages: one for human behavior, another for animal behavior. Human
rationality and superiority are not really the issue, however--one only needs 
to
read the latest Darwin Awards to notice that our species can be less rational
than advertised. The issue is the dividing line between us and the rest of
nature.

Radical behaviorists adamantly insist on this line, and look across it with
entirely different eyes than the ones they reserve for their fellow human 
beings.
They speak about animals as "them" and compare "them" with "us," as Clive D. L.
Wynne does at the beginning of Do Animals Think? ("What are animals--really? 
What
should we make of them?"). Other behaviorists, however, intentionally blur the
line. They apply the same well-tested behaviorist methodology to reconnect 
human
and animal behavior, daring to mention the words "animal" and "cognition" in 
the
same breath. They write books such as Duane M. Rumbaugh and David A. Washburn's
Intelligence of Apes and Other Rational Beings.

Of the two, Wynne's book is by far the more readable. Wynne has a pleasant
writing style and a knack for engaging the reader. He begins with the story of 
a
mad animal-rights activist who threatened the lives of people on the Isle of
Wight, where Wynne grew up. The man was convinced that animals are sentient
beings, a certainty Wynne says he wishes he could share.

This story sets the tone of doubt and reserve that permeates the book. Wynne
includes numerous insightful accounts of remarkable animal behavior, but he
invariably concludes on a note of caution: one should not infer too much from
these accounts. He is not so radical a behaviorist that he excludes all forms 
of
reasoning by animals, but he takes greater pleasure in explaining what animals
cannot do--monkeys fail to understand relations between cause and effect, apes
can sign but lack the syntax that defines human language--than in describing 
what
they can do. Capacities unique to a particular species, such as echolocation in
bats, get Wynne's full admiration. But anything that seems to elevate other
animals close to the lofty cognitive level of humankind he regards with utmost
skepticism. He seems to take delight in animals, and possesses great knowledge
about them, yet he prefers them at arm's length. The constant message is that
animals are not people.

That much is obvious. But it is equally true that people are animals. The
dichotomy Wynne advocates is outdated, lending his book a pre-Darwinian flavor.
Take the case of animal culture, currently one of the hottest areas in the 
study
of animal behavior. The idea goes back to the pioneering work of Kinji 
Imanishi,
who proposed in 1952 that if individuals learn from one another, their behavior
may grow so different from behavior in other groups of the same species that 
they
seem to have their own culture. Imanishi thus reduced the idea of culture to 
its
most basic feature: the social rather than the genetic transmission of 
behavior.

Many examples of animal culture have been documented. The classic case emerged
among wild macaques on Japan's Koshima Island. During their fieldwork with the
monkeys there, investigators provisioned them with sweet potatoes, which a
juvenile female named Imo soon began washing; she would bring her potatoes to a
small river and clean them off before eating them. Imo's washing behavior 
spread
first to her mother and then to her age peers, before affecting the rest of the
group. Later Imo moved her operation to the shoreline, washing the potatoes in
the ocean, and, again, the other monkeys followed.

Some psychologists have objected to this example, pointing out that it is
uncertain whether the monkeys learned their skill by copying others or by
discovering the behavior individually, without anyone's help. Wynne supports 
the
second view. But instead of basing his opinion on the actual data published by 
a
team of Japanese primatologists, who have worked on the problem for fifty 
years,
he relies on the word of a skeptical Westerner who has never set foot on the
island. This scientist, a specialist in rat behavior, suggested that potato
washing spread because performers were selectively rewarded by the people who
handed out the potatoes.

A few years ago I went to Koshima Island to verify the idea of selective
rewarding. I talked with some of the people who had actually witnessed Imo
cleaning her first spud. They told me that initially the monkeys were fed far
away from any water, so there was no question of rewarding any washing 
behavior.
Imo herself came up with the idea of transporting the potatoes to the river for
cleaning. They also pointed out that one cannot feed a group of monkeys any way
one wishes. The dominant males have to be fed first, the females second, and 
the
little ones last; changing the order sparks bloodshed. Thus, except for Imo's
mother, the monkeys that learned the behavior first, the juveniles, were the 
last
to be rewarded. In fact, the only monkeys on the island that never learned 
potato
washing were the adult males: precisely the best-rewarded group.

Wynne invariably favors interpretations that widen the assumed cognitive gap
between human and animal. For example, he uncritically accepts the uniqueness
claim du jour: that only human beings possess a theory of mind (ToM), or the
cognitive ability to understand that others, too, have mental states such as
thoughts and knowledge. Ironically--given Wynne's dismissal of an ape ToM--the
concept got its start with a 1970s study of chimpanzees. A female showed she 
had
grasped the intentions of others by, for example, selecting a key from among
several tools if she saw a person struggling to open a locked door.

Evidence for a theory of mind in apes has gone through its ups and downs ever
since. Some experiments have failed spectacularly, leading the proponents of 
one
school of thought to contend that apes simply lack the capacity. Negative 
results
are inconclusive, though: as the saying goes, absence of evidence is not 
evidence
of absence. Furthermore, the performance of apes is often assessed by comparing
it with that of children. Because the experimenter is invariably human, 
however,
only the apes face a species barrier. When an ingenious experiment conducted at
Emory University's Yerkes National Primate Research Center in Atlanta got 
around
that problem, the evidence for an ape ToM was more positive: chimpanzees seemed
to realize that if a member of their species had seen hidden food, this
individual knew where the food was, as opposed to one who had not seen it. That
finding threw the question of a ToM in nonhuman animals wide open again.

In an unexpected twist (because the debate has focused on humans versus apes), 
a
capuchin monkey in a laboratory at Kyoto University in Japan recently passed a
series of seeing-knowing tasks with flying colors. The least one can conclude 
is
that it is premature to settle on ToM capabilities as the ultimate Rubicon.

In spite of Wynne's dismissal of an ape ToM, his book offers many insightful
descriptions of animal behavior. A wonderful chapter on the role of messenger
pigeons during the First World War includes a picture of the stuffed body of 
Cher
Ami, a genuine war hero. The pigeon kept flying after its leg had been shot 
off,
delivering its message and thus rescuing an entire battalion.

Rumbaugh and Washburn are considerably more open-minded about the mental
accomplishments of animals than Wynne is. Their book celebrates Rumbaugh's
lifetime of research on monkeys and apes. In fact, what fascinates me the most
about Intelligence of Apes and Other Rational Beings is its historical overview
of experimental work with primates, first with the Wisconsin General Testing
Apparatus (WGTA) and later with joysticks and computers.

The WGTA was developed at the University of Wisconsin in the 1940s, and is 
still
being used today. In this set-up, a primate subject in a cage faces an
experimenter across a platform, on which differently shaped or colored stimuli
are arrayed. Both experimenter and primate can reach the stimuli; the
experimenter baits them with rewards, and the primate selects among them. I
remember working with such an apparatus as a student, testing chimpanzees to 
see
if they could discriminate shapes by touch alone. The task was so incredibly
simple and repetitive that the apes invariably got tired of the whole thing 
five
minutes into the testing. In fact, they got so bored that they performed worse
than macaques tested on the same stimuli.

I mention this episode because test performance is often taken as a measure of
intelligence, even though attention and motivation are equally important to the
outcome. As a result, failure is open to interpretation. Rumbaugh and Washburn
understand these points better than most scientists, and they are at pains to
remind the reader how the questions one asks tend to constrain the answers one
gets.

Indeed, some testing paradigms positively suppress the phenomena being tested.
When Rumbaugh replaced the WGTA with an innovative testing setup in which the
monkeys move a joystick to select stimuli on a computer screen, their 
performance
improved dramatically. Rumbaugh's work on the connection between method and
outcome should be required reading for anyone who attaches significance to
negative evidence.

One learning paradigm discussed by Rumbaugh and Washburn has special interest.
Some animals learn how to learn--that is, once they have mastered a particular
task, they can more quickly learn future tasks that have the same design but 
rely
on different stimuli. Trial-and-error learning cannot explain improved
performance in reaction to new stimuli, hence the level of learning must be
higher. But generalization across tasks is precisely what the founders of
behaviorism thought animals could not do.

Rumbaugh and Washburn discuss many forms of advanced problem-solving, which 
they
classify as "emergents." The term is slightly awkward, but the authors apply it
to cases in which animals flexibly apply accumulated knowledge to new 
situations,
resulting in an "emergent" solution. The classic example is the chimpanzee in a
room with a few sticks and boxes in one corner and, for the first time in the
chimp's experience, a banana hanging from the ceiling. The solution emerges as
the old bits of previous knowledge combine until, as if a lightbulb suddenly 
goes
on in the chimpanzee's head, he climbs on top of the boxes and reaches for the
banana with a stick.

The two authors rightly speak of reasoning and rationality, and so adopt a
terminology that is anathema to radical behaviorism. They discuss the 
behaviorist
view at length but choose to deviate from it, stressing continuity between 
animal
and human. For the reader, though, it is frustrating that they focus almost
entirely on apes and other primates, without examining how the concept of
emergents could apply equally well to other animals. Crows, dolphins, 
elephants,
and parrots have been credited with creative problem-solving as well.

There will always be tension between those who view animals as only slightly 
more
flexible than machines and those who see them as only slightly less rational 
than
human beings. The views discussed in these two books are by no means as far 
apart
as they could be; both, after all, come out of the same tradition of 
experimental
psychology. Throw in a few naturalists and neuroscientists, and the debate gets
even more complex. That said, however, the two books range widely enough across
the spectrum of views to make a powerful case that there is still plenty to be
discovered, and that human uniqueness is largely in the eye of the beholder.

Frans B.M. de Waal is C. H. Candler Professor of Primate Behavior at Emory
University in Atlanta and the director of the Living Links Center at the
university's Yerkes National Primate Research Center.

  B O O K S H E L F

By Laurence A. Marschall [4]back to top

Rats: Observations on the History and Habitat
of the City's Most Unwanted Inhabitants
by Robert Sullivan
Bloomsbury, 2004; $23.95

IN HIS MEMORABLE 1998 BOOK The Meadowlands, about the New Jersey wetlands just
west of the Lincoln Tunnel, Robert Sullivan emerged as the Thoreau of blighted
ecosystems. Traveling by canoe along oil-slicked bayous, Sullivan uncovered
treasures of both natural and industrial history no passing commuter would have
suspected.

Now Sullivan has crossed the Hudson River and relocated his eclectic wanderings
to the back alleys of lower Manhattan, where the dumpsters of Chinese noodle
joints, Irish pubs, and Salvadoran chicken takeouts are the real happening 
places
for urban wildlife. Happening, that is, if you're a rat.

"Four seasons spent among vermin" is how Sullivan describes his sojourn. His
Walden Pond was Edens Alley, a narrow defile a few blocks from Wall Street.
Equipped with both binoculars and a night-vision monocular, he arrived in the
evenings after dark to watch the rats as they emerged to feed and, in the
notebook he'd brought along, to wax lyrical about nature, civilization, and the
meaning of life. A typical entry from his winter journal:

   5:44--The rats retreat suddenly. The reason: three men enter the alley, 
though
   when I see the men I wonder which creature left the alley for which
   creature--sometimes it seems as if the rats' departure is a courtesy extended
   by the rats. . . . I think of all the rats that have crawled through this
   alley before, the history of this alley's previous inhabitants. Oh, to
   know--to really know--this pellicle of rat-infested ground.

Such deadpan effusiveness over creatures commonly regarded as loathsome may
border on sick humor, but elegies to Rattus norvegicus make up only a small 
part
of Sullivan's book. There are many stories about the ethology, natural history,
and social importance of rats, and, overall, plenty of evidence that people and
rats have a lot more in common than most people would like to admit.

Sullivan cites Martin W. Schein, for instance, the co-author of a 1953 paper on
the eating habits of rats captured on Baltimore backstreets. Schein conducted
laboratory studies using authentic garbage from the alleys where the rats were
trapped. He learned that rats hate raw beets (I sympathize) and that scrambled
eggs and macaroni and cheese are popular rat comfort foods, just as they are 
for
human Baltimoreans. In Edens Alley, according to Sullivan, the rats also seem 
to
like chicken pot pie.

In spite of some strong dislikes, though, rats are not picky eaters. By and
large, they are omnivorous and highly adaptable--the same traits that make 
people
so successful--and they show uncanny cleverness in finding food and avoiding
peril. Ann Li, an epidemiologist with the New York City Department of Health,
takes Sullivan on a rat-trapping expedition to Brooklyn, and tells him she 
thinks
rats are "so underappreciated." Even the exterminators who show Sullivan how to
outsmart the rodents express a grudging admiration for their prey.

As much as he shares the rodentophilia of his informants, Sullivan is unsparing
when he recounts the misery rats cause. Sometimes they attack directly: in 1979 
a
large pack surrounded a woman on a street in downtown Manhattan. And of course
they carry infectious diseases such as plague. Yet unless people find a way to
steam-clean each crevice of the city every day, rats will continue to cohabit
with us in uneasy harmony. "If you killed every rat in New York City," Ann Li
remarks, "you would have created new housing for 60 million rats."


Running with Reindeer: Encounters in Russian Lapland

Running with Reindeer:
Encounters in Russian Lapland
by Roger Took
Westview Press, 2004; $27.50

FEW PLACES IN EUROPE are as far off the beaten track as the Kola Peninsula, a
potato-shaped carbuncle of land at the top of the Scandinavian Peninsula, east 
of
Finland. Russian Lapland, as the Kola is also known, has one large city
(Murmansk), a few subsidiary industrial centers and mining towns, and a
scattering of isolated villages in the hinterlands. One passable highway runs
through the province. But beyond that right-of-way, for hundreds of kilometers 
in
every direction, the hardy traveler encounters nothing but tundra, taiga 
(boreal
forest), and vacant shoreline.

Roger Took is just such a hardy traveler--perhaps even a foolhardy one. When he
arrived in the Russian northland in the early 1990s, the entire country was
teetering on the edge of anarchy, and it was not clear which disaffected group 
a
lone Englishman should be more afraid of: suspicious Sami tribesmen, the 
military
attached to the remnants of the Russian Northern Fleet, or the legendary 
Russian
Mafia. Just in case, Took offhandedly notes, he learned how to fire, strip, and
reassemble a nine-millimeter semiautomatic pistol before he left London.

We never learn whether Took ever fired the pistol, but readers can be grateful
that he survived, met many fascinating characters, and kept coming back, year
after year, for more than a decade. The Kola, he discovered, is a land of
contrasts and contradictions, shaped by history and politics as much as by
geography. Its first inhabitants were nomadic Sami, who roamed freely through
northern Scandinavia. In the Middle Ages, settlers called Pomors arrived from 
the
more populated regions of Russia, to the south. A brisk fur trade with Europe
developed because the Kola Peninsula's best harbors, warmed by the northernmost
hook of the Gulf Stream, are more or less ice-free throughout the year.

Only after the Russian Revolution did the area begin to take on its current 
look
of emptiness. In a procrustean attempt to collectivize the Sami economy, Stalin
had villagers herded into hastily built urban areas and industrial farms. Much 
of
the coastline was declared off-limits. The discovery of rich mineral resources 
in
the Khibiny mountain range, near the center of the peninsula, only made matters
worse; soon "special settlers" were being shipped from various parts of the
Soviet Union to provide forced labor.

For the most part, today's inhabitants huddle in charmless concrete apartment
blocks, largely ignorant of the region's rich history and remarkable resources.
Took, however, has grown to love the place. Armed with little more than a
backpack and a fishing rod, he boldly wandered through military reservations,
floated down rivers with salmon poachers, sledged to hunting and herding
excursions with descendants of the Sami, and accompanied wildlife biologists 
and
archaeologists on expeditions to the interior. In one memorable episode he
hitched a ride through the backcountry on a clanking, tanklike all-terrain
vehicle (minus the gun turret), accompanying a human-rights activist who was
documenting a gulag of prison barracks.

Took reports signs of a new life for Russian Lapland. Environmentalists in 
Russia
and Scandinavia have begun to throw their weight behind efforts to clean up the
damage caused by the nuclear fleet. Shops in Murmansk now display the latest
fashions. And foreign sportsmen have begun to discover that some of the world's
greatest salmon streams run through the Kola's remote countryside. Russian
Lapland may not come off as a vacation paradise, but Took's book is a marvelous
introduction to a region of rich but almost forgotten heritage.


Sequoia: The Heralded Tree in American Art and Culture

Sequoia: The Heralded Tree
in American Art and Culture
by Lori Vermaas
Smithsonian Books, 2003; $39.95

JUST AS LEBANON is famous for its cedars, so North America is known for its
redwoods. Not only are they among the largest and most stately trees on earth,
but they thrive in settings of surpassing scenic beauty. Strolling beneath a
towering canopy of Sequoia sempervirens, the most common redwood along the
northern coast of California, one experiences a world of subtle twilight just a
few steps from the glare of a sunlit, rocky shoreline. The rarer Sequoiadendron
giganteum, whose ponderous trunks make their coastal cousins seem almost 
willowy,
grow farther inland, in sheltered groves in Yosemite and other isolated 
valleys.

It is no wonder, then, that the giant sequoias have assumed symbolic importance
far out of proportion to their restricted habitat. Lori Vermaas, a cultural
historian, has written an insightful new survey of American art and literature 
on
redwoods from the nineteenth and early twentieth centuries.

The most widespread early depictions of the giant trees, in the years during 
and
just after the Civil War, were made by enterprising commercial artists who used
twin lenses on their cameras to create so-called stereo-view cards. Many of the
pictures focused on the immense scale of the trees; a favorite subject was the
Grizzly Giant, a tree in Yosemite National Park whose trunk soared straight
skyward but whose upper branches seemed painfully gnarled, like the rheumatic
joints of an old man.

To a nation still smarting from the horrible conflict between the states, the
redwoods, far removed from the scene of battle, seemed serene, impassive, and
impervious to harm. They epitomized the part of the nation that had remained
intact and functional despite the fires of war and social turmoil. Huge 
paintings
of sequoias by such landscape artists as Albert Bierstadt were all the rage
(oversize landscape paintings being the functional equivalents of IMAX films).

Yet few envisioned the giant trees as symbols of an endangered environment.
Toward the end of the nineteenth century, logging them was even seen as an
example of humankind's ability to bend nature to its will. Woodsmen were "no 
puny
impersonations of men," but men who swung "heavy, keen-edged axes as though 
they
were mere trifles." Logging teams were typically photographed in the yawning
notches of trees they were about to topple. In one particularly striking print,
an entire troop of U.S. cavalrymen, mounted on horseback, stand like conquering
gladiators atop and along the length of the trunk of a fallen giant.

Exuberantly expansive, the American imagination invoked sequoias as a natural
treasure, but a treasure to be expropriated and spent. Even John Muir, one of 
the
nation's first conservationists, waxed enthusiastic over the use of redwood
lumber in construction. Redwood housing was "almost absolutely unperishable."

The onslaught of logging operations, among other abuses of the era, sparked the
modern environmental movement, and redwoods came to be seen as treasures to
preserve. Although groves of redwoods are continually threatened, the trees 
still
stand, and pictorialists in the tradition of Ansel Adams have continued to use
the image of the redwood as an emblem of strength and endurance. Vermaas helps 
us
understand the symbolism of sequoias, but even she must admit that the best way
to appreciate them is on foot and close-up. "No one has ever successfully 
painted
or photographed a redwood tree," wrote John Steinbeck in 1962. "The feeling 
they
produce is not transferable."

Laurence A. Marschall, author of The Supernova Story, is the W.K.T. Sahm
professor of physics at Gettysburg College in Pennsylvania, and director of
Project CLEA, which produces widely used simulation software for education in
astronomy.


Moving Mountains
By Robert Anderson

CALIFORNIA'S SANTA MONICA MOUNTAINS, where I live, are a mere 5 million years
old. Like most mountains, they are comprised of rocks formed during complex and
repeated sequences of uplift, sedimentation, and volcanism. In the case of the
Santa Monica range, the process began about 200 million years ago, when the 
first
dinosaurs were roaming the planet.

A summary of the processes that make mountains rise can be found at
www.physicalgeography.net, a Web site created by Michael J. Pidwirny, a
geographer at Okanagan University College in Kelowna, British Columbia. (On the
home page click on "Fundamentals: Online Textbook" from the menu bar at the 
top;
in "Chapter 10: Introduction to the Lithosphere," click on "Mountain 
Building.")
For an overall view of how colliding tectonic plates transform the planet, go 
to
"Dynamic Earth" ([6]earth.leeds.ac.uk/dynamicearth), developed by Robert 
Butler,
a geologist at the University of Leeds.

Illustrations of the way tectonics has changed the distribution of land and sea
can also be found at a Web site run by Christopher R. Scotese, a geologist at 
the
University of Texas at Arlington. For thirty years, Scotese and his 
collaborators
have been working on a series of paleogeographic atlases. The latest of them, 
the
Global Plate Tectonic Model, is available at PALEOMAP Project
([7]www.scotese.com). From the home page you can choose 3-D movable paleoglobes
and paleogeographic animations that show the positions of the continents and 
the
shapes of the ocean basins for various periods of geological time. Select Earth
History from the menu at the left on the home page. There youll find full-color
maps depicting details such as mountain ranges, shorelines, and active plate
boundaries during those same periodsbeginning with the breakup of the first
supercontinent, Rodinia, and extending through the present and into the future
for 250 million years, when the supercontinent Pangea Ultima will trap what is
now the Atlantic Ocean in a small, inland basin.

Antonio Schettino, a geologist in Milan, Italy, worked with Scotese to 
re-create
plate motions in the Mediterranean region
([8]www.itis-molinari.mi.it/Intro-Med.html). The accompanying QuickTime 
animation
provides an excellent graphic explanation of how the Alps arose. A similar
presentation of tectonic processes shows the ancient mountain chains in greater
regional detail ([9]www4.nau.edu/geology). Click on "Popular Departmental 
Links"
and look at the three items created by Ronald C. Blakey, a geologist at 
Northern
Arizona University. The site 
[10]www.jamestown-ri.info/northern_appalachians.htm
provides a rundown of the northern Appalachian chain's geological history, 
which
stretches back a billion years.

Geologists can now watch mountains grow, thanks to new satellite and radar
technologies that measure minute movements of the Earth's crust and slight
changes in the stresses that cause earthquakes. Go to the "Active Tectonics"
site, run by a group from the University of California, Berkeley
([11]www.seismo.berkeley.edu/~burgmann/EDUCATION/InSAR.html), for more
information.

Robert Anderson is a freelance science writer living in Los Angeles.

References

6. http://earth.leeds.ac.uk/dynamicearth
7. http://www.scotese.com/
8. http://www.itis-molinari.mi.it/Intro-Med.html
9. http://www4.nau.edu/geology
   10. http://www.jamestown-ri.info/northern_appalachians.htm
   11. http://www.seismo.berkeley.edu/~burgmann/EDUCATION/InSAR.html