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Evolutionary theory
helps Russell Gray
explain why crows
can make tools like
this hooked lever.
No miracles
Biologist Russell Gray uses evolutionary ideas to probe
the origin of languages and complex thinking
PHOTO: GODFREY BOEHNKE
By Virginia Morell, in Auckland, New Zealand
“I
’m a man of enthusiasms,”
said Russell Gray, binoculars
and fishing pole in hand as he
bounded up a trail on Tiritiri
Matangi Island, a wildlife sanctuary off the coast of the city,
“and birding and fishing are
just two of them.” Fair and almost boyishly animated, Gray,
54, set off with long, energetic strides into
the forest, where he eagerly pointed out the
island’s rarest birds, expounded on its ecological history, and happily described a giant
fish he’d once caught, as well as the sauce
with which he’d served it. “I’m enthusiastic
about food and wine, too,” he said, beaming.
Then he paused for a moment to point out
a pair of pied cormorants, large, long-necked
waterbirds at the water’s edge. “The subject
of my first evolutionary study,” Gray said, “so
I have a fondness for them.”
As unlikely as it might seem, the cormorants and other seabirds set Gray on a career
path into the evolution of human linguistics
and culture. Although the full list of Gray’s
enthusiasms would fill this page, suffice it
to say that evolutionary biology is at the
top. Using its principles, Gray, an evolutionary biologist and comparative psychologist
at the University of Auckland, has helped
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crack open two areas—animal cognition
and historical linguistics—long regarded by
many as black boxes, impenetrable to the
scientific method.
Because languages change at unpredictable rates, analyzing their relationships
was for many linguists more of an art than
a science. But by applying evolutionary
methods borrowed from genetics, Gray and
his colleagues are transforming the discipline, shaping it into a science of prehistory.
His group has unraveled the histories of
the Austronesian and Proto-Indo-European
(PIE) languages and peoples, and traced
their migrations over vast distances.
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The roots of Indo-European languages
Indo-European languages today extend from the British Isles to India, as seen in a map
of some of the major subfamilies, but Gray's work roots them all in Anatolia (brown). He dates
the origin of Proto-Indo-European to about 7600 years ago (right).
Celtic
Italic
Germanic
Balto-Slavic
Indo-Iranian
Each triangle represents a group of related
languages (see key, left) that blossomed
over time from a single tongue.
Albanian
Greek
Armenian
Tocharian
Anatolian
0
1000 2000 3000 4000 5000 6000 7000 8000
Time (years ago)
Although controversial, his papers have
of waterbirds that includes cormorants and
so stirred the field that several researchpelicans), in 1996 Gray and his colleagues
ers credit him with being “in the vanguard
created 12 behavioral family trees and
of a revolution,” as evolutionary biologist
compared them with published morphoMark Pagel of the University of Reading in
logical and genetic trees. The trees largely
the United Kingdom puts it. Gray’s fresh apmatched, showing that birds with similar
proach prompted Germany’s Max Planck Sobehaviors, such as open-billed courtship
ciety to tap him as a co-director of its new
displays, shared a common ancestry.
Institute for History and the Sciences in Jena.
For Gray, “it didn’t seem a huge leap to
The Max Planck officials who interthink of human languages in the same way.
viewed Gray weren’t even aware of his
… Words are inscribed, in their shape and
other research focus, animal cognition. The
form, with a powerful record of the past.”
question of how complex thinking evolved,
Growing up in New Zealand, he had heard
like the origin of languages, was thought
Polynesian languages, including Maori, Tonto be beyond the ken of science.
But this black box, too, yields to
evolutionary thinking, insists
Gray, who leads the University of
Auckland’s highly regarded project on New Caledonian crows,
which have astonished biologists
and the public with their skill at Russell Gray, University of Auckland
fashioning simple tools. “There’s
a reason these crows make tools and other
gan, and Samoan, and just by listening he
birds don’t,” he says. “It’s not a miracle.”
could tell that they must be closely related.
As with the seabirds’ behaviors, he suspected
THAT SENTENCE, along with the even
that the Pacific Island languages had come
shorter phrase “no miracles,” is a favorite
about through “some kind of descent with
of Gray’s.
modification.” His key insight: “Words are
The power of evolution “to explain many
just like genes,” in that they resemble each
things,” as he puts it, struck him when
other because of shared ancestry.
he was still in high school in Tauranga,
For example, “mother” in English and
south of Auckland, after reading Richard
mutter in German sound alike because they
Dawkins’s The Selfish Gene. Hooked, Gray
derive from the same PIE word, mehter. Linpursued this enthusiasm, earning his docguists call such words cognates, and they’ve
torate and landing a position at the Unilong used them to construct trees showing
versity of Otago, Dunedin. “It’s on South
the relationships among languages.
Island, where there are fantastic seabirds,
Gray took the analysis further: He realized
and I developed a new interest—seabird
that the sophisticated software designed to
behavior.” Using existing descriptions of the
trace genetic lineages could be applied to
social displays of Pelecaniformes (an order
languages. In 2000, he and a colleague pub-
lished a Nature article using language trees
to test competing hypotheses about the
settlement of the Pacific by people speaking ancestral Austronesian: a rapid “express
train” of peoples who spread from Taiwan
across the widely scattered islands in a few
thousand years, or an “entangled bank” of
Austronesian and other speakers who mixed
more slowly over a longer period. Using
77 Austronesian languages and 5185 words
and phrases, they found that Taiwanese
languages were the oldest, and that their
spread matched that of express train settlement, with Indonesian and coastal New
Guinean languages hiving off
before those in New Zealand and
Hawaii.
“I was just delighted when that
paper came out,” says Pagel, who
also studies the evolution of language. “He showed that you can
test questions of human history
with linguistic data.”
The team extended their Austronesian
analysis with more sophisticated statistics in
2009, finding that these languages diverged
and changed in fits and starts that could be
timed and tied to specific inventions, such
as the outrigger canoe and sail (Science, 23
January 2009, p. 479). “It’s kind of wild to
think you can get these types of results from
comparing language lists,” says Andrew Garrett, a historical linguist at the University of
California, Berkeley.
But when Gray and his colleagues applied their techniques to an even bigger
question—the origin of the Indo-European
language family, which includes English,
Spanish, Russian, Hindi, and Urdu among
many others—Garrett and other linguists recoiled at the results.
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“It’s hard to overstate just how contentious
my linguistic work is. People … have left
the room when we present our results.”
PHOTO: SIMON WALKER/UNIVERSITY OF OXFORD
As with the settlement of the Pacific,
lar clocks, he notes. But they found a way
Gray says. “But to me, these are empirical
there were two competing hypotheses: that
around the problem by creating a “relaxed”
questions. We don’t have to just wave our
PIE originated among Anatolian farmers
clock—software programs that allow the
arms. There are no miracles.”
about 8000 to 9000 years ago and expanded
rates of change to vary and statistically
Gray intends to keep his New Caledonian
with their settlements, or that it arose only
compare numerous trees.
crow project going, too. In his view, the
about 6000 years ago on the steppes north
Despite the criticisms, Garrett says that
field of animal cognition suffers from the
of the Black and Caspian seas, and spread
he and many other historical linguists now
same deficiency as linguistics once did: “Its
via the horses and wheeled carts of semirecognize the power of Gray’s biological aptheories haven’t been sufficiently shaped
nomadic herders and warriors. Most linproach and are employing it themselves. He
by evolutionary thinking.” Researchers
guists favored the latter hypothesis.
and his colleagues will soon publish their
often discover one or two species doing
In successive papers, Gray’s group used
own phylogenetic analysis of PIE, which
something clever and immediately “comevolutionary software to analyze the vocabuincorporates what he considers more accupare them to humans. That’s not thinking
laries of 103 ancient and modern European
rate cognates and models the relationships
like an evolutionist,” he says. Instead, Gray
and Asian languages. They produced phyloamong languages differently. Their findings
and his team seek intermediate steps, degenetic trees and ended up with a date for
support the steppe hypothesis.
vising tests for the crows that reveal menthe origin of PIE at 7600 years ago.
tal limitations as well as talents.
Then they applied a method from
In a hotel lobby, he produced a
another branch of biology, using
palmlike pandanus leaf that a crow
a software program developed to
had carefully crafted into a stepped
determine the geographic origin of
rake; the birds use these to forage
viral pathogens (Science, 24 August
for grubs and insects. “When you
2012, p. 957). The resulting trees and
see a bird make a tool like this,”
maps showed Anatolia as the homehe explained, “you immediately
land and supported the earlier date.
think they have some understandMany linguists disliked both the
ing of the physical properties of
results and the methods. “It’s hard
things and cause and effect.” But
to overstate just how contentious
that’s an assumption that may not
my linguistic work is,” Gray says.
be warranted.
“People at linguistic conferences
For instance, Gray’s group has
have left the room when we presprobed the crows’ understanding
ent our results.”
of a string-pulling test that’s been
Linguists don’t object to Gray’s
cited as evidence that the birds
language family tree, which basithink about a problem the way a
cally matches the one devised ushuman might. In the test, a crow
ing traditional methods. But they
sees a piece of meat dangling
object to his place and date of orifrom the end of a string that’s atgin for PIE. His conclusions are at
tached to a branch. She flies to the
odds with “the best archaeological
perch, reels in some of the string
scenario for the origin and diverwith her beak, and steps on it to
sification of the Indo-European
keep it anchored while she pulls
language family,” says Don Ringe,
in more, until she gets the treat.
a historical linguist at the UniverShe gives the impression that she
sity of Pennsylvania. That scenario
understands that stepping on the
is based in part on cognates for the
string helps keep it short. Yet when
word “wheel,” which dot numerA New Caledonian crow pries out dinner with a tool of his own manufacture.
Gray’s group challenged her with
ous branches of the Indo-European
variations of the string-pulling
language tree, from Sanskrit to Greek to
Still, Garrett adds, “the fact that we’re dotest (none of which would have stumped
Germanic. Linguists say these cognates all
ing these phylogenetic analyses of language
a human), she failed them all. “So, no,
stem from a PIE word reconstructed as
at all is entirely due to [Gray]. In 10 to
she isn’t thinking about the problem exk’ek’los, which must have first been spoken
20 years, every historical linguist will be doactly like we would,” Gray says. “And we
about 5500 years ago—the archaeological
ing research this way because the tools are
shouldn’t expect that. That’s not the way
date of the first wheels. And those early
so powerful—and Gray has been so creative
evolution works.”
wheels and axles are associated with steppe
in their use.”
Back on Tiritiri Matangi Island, Gray’s
peoples, not Anatolian farmers.
passion for birding beat out that for fishCritics like Ringe also cringed at Gray’s
AT THE MAX PLANCK, Gray won’t be exing, as rarely seen species flew into view. As
quantitative method, because it uses the
ploring only linguistics. His mandate exhe boarded the ferry back to Auckland, talk
varying rates at which words change. Such
tends to culture, and he’s already enthusing
turned to the sea north of New Zealand.
rates are a staple of glottochronology, a
over the prospect of applying phylogenetic
There lie the islands of Vanuatu, site of annow-discredited technique once used to
methods to questions such as what societal
other enthusiasm Gray plans to explore at
date the timing and spread of languages.
factors lead to belief in an omnipresent dethe Max Planck. “It has the greatest density
“The problem with glottochronology was
ity or how large states develop from small
of languages; it’s like the Galápagos of lanthat it assumed words change at a steady
tribal bands. “Cultural anthropologists
guage evolution, and we’re going to find out
rate,” Gray says. Biologists made the same
think there aren’t any rules for how powhy,” he says. “I can guarantee you, it’s not
error when constructing their first moleculitical structures or religions come about,”
a miracle.” ■
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