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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
SCIENCE sciencemag.org
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. 19 SEP TEMBER 2014 • VOL 345 ISSUE 6203
Published by AAAS
1443
Downloaded from www.sciencemag.org on November 11, 2014
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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.
1444
sciencemag.org SCIENCE
19 SEP TEMBER 2014 • VOL 345 ISSUE 6203
Published by AAAS
CREDIT: ADAPTED FROM R. BOUCKAERT ET AL., SCIENCE 337, 6097 (24 AUGUST 2012)
“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.” ■ SCIENCE sciencemag.org
19 SEP TEMBER 2014 • VOL 345 ISSUE 6203
Published by AAAS
1445
NEWS
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
SCIENCE sciencemag.org
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. 19 SEP TEMBER 2014 • VOL 345 ISSUE 6203
Published by AAAS
1443
Downloaded from www.sciencemag.org on November 11, 2014
FEATURES
NEWS | F E AT U R E S
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.
1444
sciencemag.org SCIENCE
19 SEP TEMBER 2014 • VOL 345 ISSUE 6203
Published by AAAS
CREDIT: ADAPTED FROM R. BOUCKAERT ET AL., SCIENCE 337, 6097 (24 AUGUST 2012)
“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.” ■ SCIENCE sciencemag.org
19 SEP TEMBER 2014 • VOL 345 ISSUE 6203
Published by AAAS
1445
![[Electricity - no miracles but remarkable effects].](/assets/img/hold.png)
