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Language gene found
The first linking of a gene to language could speed our understanding
of this most unique and most controversial of human abilities.
4 October 2001
JOHN WHITFIELD
Language problems run in the 'KE' family. Members of several
generations speak "as if each sound is costing them their soul", one
researcher has said. They struggle to control their lips and tongue,
to form words, and to use and understand grammar. "To the naive
listener, their speech is almost unintelligible," says geneticist
Anthony Monaco, of the University of Oxford in England.
Researchers today unveil the single gene that, when it goes wrong,
causes this speech breakdown. The gene - the first to be definitively
linked to language - switches others on and off, and so could lead
the way through a genetic network of language learning and use.
It's an unbelievably complex system, and we've got one tiny glimpse
Michael Tomasello, Max Planck Institute for Evolutionary
Anthropology, Leipzig
Finding one gene is like finding one part of a car. It looks useful,
as though it's part of a larger mechanism. But we don't know what it
does, what other parts it interacts with, or what the whole vehicle
looks like. "It's an unbelievably complex system, and we've got one
tiny glimpse," says Michael Tomasello, a psychologist at the Max
Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
We shouldn't have to wait long for more parts to turn up. Geneticists
are on the trail of genes that control brain development and affect a
range of mental disorders. The human genome sequence lets them do
much of the groundwork on a computer, "saving what used to be months
of work", says Robert Plomin, a behavioural geneticist at London's
Institute of Psychiatry.
Forked tongue
The study of language divides researchers almost as starkly as
languages themselves divide us. They disagree about whether language
abilities are an innate feature of our biology or a product of our
social interactions. Their opinions differ about whether the brain's
language centres are specialized for these tasks alone, or are a part
of our general mental machinery.
The controversy centres on theories first put forward by Noam Chomsky
in 1959. That children learn to talk without instruction, and that
adults construct an infinite number of new sentences from a finite
number of words, convinced Chomsky that humans possess an
inbuilt 'universal grammar' - a set of rules about the structure of
language.
Forty years on, these ideas remain controversial. "You have to decide
which side you're on - there's not much middle ground," says Bruce
Tomblin, who studies the genetics of speech disorders at the
University of Iowa in Iowa City. Tomasello, for example, believes
that it is our ability to use abstract symbols that distinguishes
humans from other animals, and is more likely to be genetically
encoded in some way. Grammar, he says, "emerges historically - it's a
sociological product, not genetic".
Genes build brain structures in such a way as to inform children what
to expect Martin Nowak, Institute for Advanced Study, Princeton
You don't need to believe in special language genes to believe, like
Chomsky, in specialized, uniquely human language structures of the
brain. "I don't think there are genes just for language, rather that
genes build brain structures in such a way as to inform children what
to expect," says Martin Nowak, who studies the evolution of language
at the Institute for Advanced Study in Princeton. "It's impossible to
learn language if we don't have a brain structure defined to expect
it."
Family code
Family KE was first described in 1990. The way the disorder was
shared out between the generations made it clear that just one gene
was responsible, and the discovery was initially trumpeted as a 'gene
for grammar'. When the breadth of the family's impairments became
clear, there was a retreat from this claim - "I've heard it called
the cold fusion of our field," says one psychologist.
The controversy still smoulders over whether the KE's symptoms have
more to do with their inability to control their mouths, or some
general brain problem, than with language centres. Supporters of a
more purely linguistic interpretation of the family's difficulties
point to the fact that the family's IQ, although below average, is
within the normal range.
Monaco's team had been hunting the KE gene for several years. By
1998, they had pinned it down to an area of chromosome 7. Data from
the Human Genome Project suggested that there were about 70 genes in
this area. "We were marching down the chromosome," he says, using
genetic markers to progressively narrow down the area that might
contain the gene.
Two years ago, their march became a run. 'Patient CS', an unrelated
boy with very similar difficulties to the KEs, turned up. Comparing
the two allowed the researchers to stop their laborious rummage
through chromosome 7 and zoom in on the gene. "It probably saved us a
year or two," says Simon Fisher, another member of the Oxford team.
The same gene, called FOXP2, is damaged in the new patient and in the
afflicted KEs. It belongs to a group that controls the activity of
other genes by making a protein that sticks to DNA. The mutations in
family KE and patient CS disrupt the DNA-binding area of the protein.
FOXP2 is an important piece of the genetic puzzle of language
Karin Stromswold, Rutgers University, New Jersey
FOXP2 is "an important piece of the genetic puzzle of language", says
psychologist Karin Stromswold of Rutgers University in New Jersey.
But most language impairments are nowhere near as severe as those
afflicting the KEs, and the patterns of inheritance in most families
with language disorders are also more complex. The gene's "very
messy" effects necessitate further studies of families with more
limited impairments, cautions Stromswold.
Monaco's team is currently scanning the genomes of such families."I
would be extremely surprised if the FOXP2 gene were a major
determinant of more specific language impairments," he says.
FOXP2 is not unique to humans - it is switched on in the lungs and
brain of mice. But subtle differences in its sequence or workings may
illuminate why humans talk and animals don't, and how our ability
evolved.
Ultimately, "we need to understand how genes give rise to brain
structure, and how our brain structure gives rise to language", says
Nowak. This job is just beginning: a full grasp of such processes
is "50 to 100 years away", he says.
Shaking the tree
The network of language genes may be like a tree. Genes such as FOXP2
could be at the trunk - where sawing through them would knock out
lots of aspects of language. Other genes might fine-tune aspects such
as grammar further down the line; knocking these out would be
analogous to lopping off a branch.
Psychologist Heather Van der Lely, of University College London,
subscribes to this school of thought. She studies children whose
speech and understanding of individual words are fine, but who, like
normal adults learning a foreign language, are unable to master
grammar. Such children muddle their tenses, saying 'yesterday I jump
the fence', for example, and struggle to phrase questions.
Scientists study children who struggle with grammar.
© SPL
"You have to explicitly teach them the rules of language," says Van
der Lely. "They never have an intuitive knowledge - they always have
to stop and work it out." These are the kind of 'pure' language
deficits Stromswold wants gene-hunted. They lead van der Lely to
believe in specialized grammar circuits in the brain, and genes to
control their development.
Unsurprisingly, not everyone agrees. "It's hard for me to believe
that we have genes devoted to influencing the brain in very specific
ways that affect language and only language," says Tomblin. He thinks
speech emerges from "general-purpose cognitive mechanisms, some of
which may be more important for language than others. It's a less
tidy view of things, but as I see the data, it looks more tenable."
Even apparently pure language disorders may be caused by complex
interactions of many factors, warns Plomin. He believes there may be
lots of different ways - genetic errors or environmental insults - to
reach the same end language problem.
Sliding scale
People differ widely in their linguistic ability and behaviour - the
age at which they begin speaking, for example, and the speed with
which they master language. Plomin says that language development is
probably controlled by "many, many genes, each with a small effect,
working in many bits of the brain". Rather than language being
something that you've got or you haven't, says Plomin, all these
genes conspire to place people somewhere on the scale of linguistic
ability.
Plomin is involved in a study of 16,000 pairs of British twins. It
has found a strong heritable component to language disorders, but
individual genes are hard to pin down: "I'm optimistic, but progress
has been a lot slower than people thought it would be," Plomin says.
The genes and brains of unusually gifted linguists, people who can
speak many different languages fluently, for example, might also
reveal other genetic contributions to language learning. This
approach has been neglected, Stromswold says, but a "surprising
number" of professional linguists are the offspring of other
linguists. "Linguists who marry linguists should trot on down to
their local genetics centre," she adds.
A surprising number of professional linguists are the offspring of
other linguists
It would be particularly interesting if their brains didn't work so
well in other areas. "I'd look for linguists who can't balance a
cheque-book," Stromswold says.
© Nature News Service / Macmillan Magazines Ltd 2001
Scientists Identify a Language Gene
Bijal P. Trivedi
for National Geographic Today
October 4, 2001
Researchers in England have identified the first gene to be linked to
language and speech, suggesting that our human urge to babble and
chat is innate, and that our linguistic abilities are at least
partially hardwired.
"It is important to realize that this is a gene associated with
language, not the gene," said Anthony Monaco of the University of
Oxford, England, who led the genetic aspects of the study.
Pathway to Human Communication
The newly identified gene associated with language ability is
required in early development of an embryo to ensure the formation of
brain regions involved in speech and language functions.
The gene is required during early embryonic development for formation
of brain regions associated with speech and language.
The gene, called FOXP2, was identified through studies of a severe
speech and language disorder that affects almost half the members of
a large family, identified only as "KE." Individuals with the
disorder are unable to select and produce the fine movements with the
tongue and lips that are necessary to speak clearly.
"The most obvious feature is that they are unintelligible both to
naive listeners and to other KE family members without the disorder,"
said neurologist Faraneh Vargha-Khadem of London's Institute for
Child Health, who studied the family. The members of the family also
have dyslexic tendencies, difficulty processing sentences, and poor
spelling and grammar.
FOXP2 is responsible for the rare disorder seen in the KE family that
is a unique mixture of motor and language impediments, said Monaco.
But, Monaco cautioned, "FOXP2 is unlikely to be the cause of less
severe language deficits that affect approximately 4 percent of
schoolchildren. FOXP2 will not be the major gene involved in most of
these cases."
Their findings are published in the October 4 issue of the journal
Nature.
Using data from the KE family, researchers narrowed the location of
the FOXP2 gene to a region of chromosome 7 that contained about 70
genes. Analyzing these genes one by one is a task that could easily
have taken more than a year. But Monaco's team made a breakthrough
when researcher Jane Hurst of Oxford Radcliffe Hospital identified a
British boy, unrelated to the KE family, who had an almost identical
language deficit.
The boy, known as "CS," had a visible defect in chromosome 7 that
specifically affected the FOXP2 gene. "The defect was like a
signpost, precisely highlighting the gene responsible for the speech
disorder," said Monaco.
The FOXP2 gene produces a protein called a transcription factor,
which attaches itself to other regions of DNA and switches genes on
and off.
In the KE family, one of 2,500 units of DNA that make up the FOXP2
gene is mutated. Monaco suggested that this mutation prevents FOXP2
from activating the normal sequence of genes required for early brain
development.
"It is extraordinary that such a minute change in the gene is
sufficient to disrupt a faculty as vital as language," he said.
Although humans have two copies of every gene, just one mutated copy
of FOXP2-as in the case of both CS and the KE family-can have
devastating effects on brain development, said Vargha-Khadem.
Brain imaging studies of the KE family revealed that affected members
have abnormal basal ganglia-a region in the brain involved with
movement-which could explain difficulty in moving the lips and
tongue. Regions of the cortex involved in speech and language also
appear aberrant.
The discovery of FOXP2 offers Monaco and other geneticists a probe to
fish for other genes involved in development-specifically those
directly controlled by FOXP2.
Also in progress is a collaborative project to study the evolution of
the human FOXP2 gene by comparing it with versions in chimps and
other primates. Monaco speculates that differences between the FOXP2
gene in humans and chimps may reveal a genetic basis for differing
abilities to communicate.
First language gene discovered
A few changes in a gene explains why chimps can't talk
By Helen Briggs
BBC News Online science reporter
Scientists think they have found the first of many genes that gave
humans speech.
Without it, language and human culture may never have developed.
Key changes to a gene in the last 200,000 years of human evolution
appear to be the driving force.
Language could have been the decisive event that made human culture
possible
Wolfgang Enard, Max Planck Institute
The gene, FOXP2, was the first definitively linked with human
language.
A "mistake" in the letters of the DNA code causes a rare disorder in
humans marked by severe language and grammar difficulties.
The gene was discovered last year but now scientists have studied the
DNA of apes to see what sets us apart from our closest animal
cousins.
Mice to men
German and British researchers looked at the chimp, gorilla, orang-
utan, rhesus macaque monkey and mouse.
They wanted to see how the gene differed in mice, monkeys and man.
Learning to speak: An instinct with genetic roots
They found slight but crucial changes to the chemical sequence of the
gene that happened during the passage of time.
"This is hopefully the first of many language genes to be
discovered," says Wolfgang Enard of the Max Planck Institute for
Evolutionary Anthropology in Leipzig, Germany.
"It happened in the same time frame when modern humans evolved," he
told BBC News Online.
"It is compatible with the hypothesis that language could have been
the decisive event that made human culture possible."
Genetic roots
Changes to two single letters of the DNA code arose in the last
200,000 years of human evolution.
They eventually spread throughout the human population along with our
unique capacity for speech.
"The idea is that these changes gave some people an advantage because
they were able to communicate more clearly," says co-author Simon
Fisher of the Wellcome Trust Centre for Human Genetics at the
University of Oxford, UK.
"This variation in the gene expanded in the population and became
fixed so everybody had what is now the human version of the gene."
The possibility that language has genetic roots was first raised in
the 1960s.
Scientists argue that there must be a genetic basis to speech and
language.
It is universal, complex and acquired almost instinctively by
children at a young age.
'Hard to digest'
The sequence change identified by the German and British team is
thought to be linked to an ability to control facial movements - a
faculty crucial to language.
John Haught, Professor of Theology at Georgetown University,
Washington DC, is not surprised by the finding, reported in the
online edition of the journal Nature.
"What may be harder to digest is that such a momentous outcome as
language and culture seems to be so exquisitely dependent on a
physically infinitesimal genetic difference that allowed for a
certain kind of facial movement in our ancestors," he says.
The researchers stress that other speech and language genes are
likely to be discovered.
According to Wolfgang Enard there could be anywhere between 10 and
1,000 such genes.
"We don't think this is THE speech gene," Dr Fisher told BBC News
Online.
"It influences the ability to speak clearly. The mutation doesn't
remove the capacity for speech completely."
Language Gene May Be Linked to Development of Modern Humans
by Michael D. O'Neill
About 50,000 years ago, the ancestors of modern humans began to
display a daunting variety of new behaviors. Where once very similar
stone-age methods had been the rule throughout the world, suddenly,
almost from valley to valley, new and different technologies were
developed. In addition, evidence of religion, burials, art, and magic
was seen for the first time.
Prominent anthropologist Dr. Richard G. Klein [link a, link b, link
c] of Stanford University has suggested that the most likely cause of
this quantum behavioral advance was the development of sophisticated
communication ability, i.e., language (1).
Now, high-powered comparative DNA analysis, enabled by technology
from Applied Biosystems, has provided evidence that mutations in a
recently identified gene, putatively associated with language
development, may have been responsible for this dramatic advance in
human evolution (2).
The FOXP2 Gene
The gene is called FOXP2 and it was identified in 2001 by a research
team led by Professor Anthony Monaco [link a, link b, link c],
director of the Wellcome Trust Centre for Human Genetics in the UK,
and head of the Centre's Neurodevelopmental group (3) [see related
review (4)].
The FOXP2 gene codes for a protein that shares characteristics with a
class of proteins called forkhead winged-helix box proteins (the name
FOXP2 stands for "forkhead box, subclass P, member 2"). Other members
of this class function as transcription factors [link a, link b],
proteins that influence the production of other proteins by binding
to DNA and promoting or inhibiting transcription of the genes coding
for those proteins. A number of forkhead transcription factors have
been shown to play key roles in developmental pathways, frequently by
serving to turn on the production of whole sets of proteins.
The forkhead transcription factors bind to DNA by a characteristic
100-amino-acid domain that is variously called the "forkhead" domain
or "winged-helix" domain or "forkhead/winged-helix" domain [link a,
link b, link c]. The structure of this domain is characterized by the
presence of at least three alpha helices, followed by two large loops
(or "wings") (4).
The term "forkhead" comes from the name of the gene for the first
member of this class of proteins to be identified (the fork head gene
in Drosophila) [see article on nomenclature for the winged-
helix/forkhead transcription factors (5)].
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Identifying the Language-Associated Gene
Dr. Monaco and his colleagues identified the FOXP2 gene on chromosome
7 in their genetic analysis of a unique three-generation family
(called the KE family) in which many family members had inherited a
characteristic pattern of problems in their ability to speak. The
defect was inherited as a monogenic trait in an autosomal dominant
pattern. The serendipitous identification of a similar speech problem
in an unrelated child proved crucial, as this child was shown to have
a chromosome abnormality in the same region of chromosome 7 and this
simplified the hunt for the gene.
Extensive work investigating the manifestation of the gene defect in
affected members of the KE family has been done in the last decade by
Dr. Faraneh Vargha-Khadem [link a, link b], who collaborated with Dr.
Monaco and was a senior author on the paper describing the gene
identification (3).
Affected Individuals Can't Pronounce Consonants
The defect appears to be related to a problem in the exquisite fine
muscle control (timing, coordination, etc.) of the larynx, tongue,
lips, etc., that is crucial to the articulate speech seen in humans.
Affected family members are incapable of controlling their mouths
with sufficient precision to make consonants, for instance. Other
primates do not have the ability to produce this exquisite fine
muscle control and this ability may be one of the key capabilities
that made possible the evolutionary leap to articulate speech.
Linkage Analysis of the KE Family
Linkage analysis by Dr. Simon Fisher of Dr. Monaco's team located the
defective gene to a defined region on chromosome 7 and sequence
analysis allowed Dr. Fisher and Cecilia Lai, also of the Monaco team,
to identify a mutation in a gene (FOXP2) that was associated with the
speech/language defect in all the known affected members (15
individuals) in the 37-member KE family.
Nature of the Mutation
The mutation specified a single nucleotide change that would code for
an amino acid substitution in a critical region of the FOXP2 protein,
namely within the forkhead/winged-helix region that serves to bind
the transcription factor to target DNA. Specifically, the mutation
caused a histidine to be substituted for the usual arginine at amino
acid position 553 in the 715-amino-acid protein.
The change occurs in the third helix of the forkhead/winged-helix
domain. This is the most highly conserved part of the forkhead/winged-
helix domain and the amino acid substitution occurs adjacent to a
histidine residue that makes direct contact with the major groove of
target DNA. The researchers noted that the arginine amino acid at
position 553 is completely invariant in all members of the large
family of forkhead proteins in species ranging from yeast to humans,
arguing very strongly for the importance of this arginine remaining
unchanged.
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Applied Biosystems Technology Key to Gene Identification
The Monaco team's effort to first localize and then identify the
FOXP2 gene was aided by the use of an ABI PRISM® 373 DNA Sequencer,
ABI PRISM® BigDye® Terminators, ABI PRISM® GeneScan® Analysis
Software, and ABI PRISM® Genotyper® Software, all from Applied
Biosystems [see article in BioBeat® Online Magazine (6)].
First Gene Implicated in Development of Speech and Language
The researchers had said, at the time, that their findings suggested
that FOXP2 is involved in the developmental process that culminates
in speech and language. They had noted that, to their knowledge,
FOXP2 was the first gene to have been implicated in such pathways,
and that its identification promised to offer the basis for insights
into the molecular processes mediating language.
Evolutionary Geneticist Joins the Effort
Shortly after identification of the FOXP2 gene, Professor Monaco
began a collaboration with famed evolutionary molecular geneticist,
Professor Svante Paabo [link a, link b, link c], in order to
investigate the evolutionary significance of FOXP2 changes in primate
evolution.
Dr. Paabo is director of the Max Planck Institute for Evolutionary
Anthropology in Leipzig, Germany, and head of the Institute's
Department of Evolutionary Genetics. A native Swede, Dr. Paabo is
world famous for his landmark analysis of mitochondrial DNA (mtDNA)
from late Pleistocene Neanderthal fossils (7). This analysis,
unprecedented at the time for the antiquity of the DNA studied,
provided the first compelling molecular evidence for the hypothesis
that modern humans had replaced Neanderthals and not evolved from
them. Dr. Paabo's analysis indicated that no Neanderthal-specific
mtDNA sequences are present in the mtDNA of modern humans.
Comparative Sequencing to Investigate Human/Great Ape Differences
Dr. Paabo has recently been focused on attempting to identify
differences in DNA sequences and gene expression that might lie at
the core of the physical and behavioral differences seen between
humans and their closest relatives, the great apes (chimpanzees,
bonobos, gorillas, and orangutans). The use of two ABI PRISM® 3700
DNA Analyzers from Applied Biosystems has played a crucial role in
Dr. Paabo's comparative sequencing efforts.
The FOXP2 gene, as a putative language-associated gene, seemed to be
an excellent candidate gene in which to investigate human/great ape
differences. The use of language, after all, is one of the most
significant behavioral differences seen between humans and the other
primates. And so, Dr. Paabo was particularly eager to collaborate
with Dr. Monaco in a comparative sequencing investigation of FOXP2 in
primates.
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FOXP2 in Humans, Great Apes, Monkeys, and Mice
The first effort undertaken by Dr. Wolfgang Enard in Dr. Paabo's
laboratory was to analyze the cDNA sequences of the FOXP2 gene in
humans, representative great apes (chimpanzee, gorilla, and
orangutan), a monkey (the rhesus macaque), and also in a distant
mammal (the mouse) to look for differences that might be associated
with the differences between these groups. The sequencing for this
effort was carried out on the ABI PRISM® 3700 DNA Analyzers.
[Note: the cDNA represents the portion of the DNA sequence of a gene
the specifies the amino acid sequence of the protein that gene codes
for; cDNA (complementary DNA) is synthesized from the mRNA that is
normally translated into protein].
Dr. Enard and Dr. Paabo were expecting that there would be perhaps
many, many differences between the FOXP2 cDNA sequence in the mouse
and the sequences in primates (separated by 130 million years of
evolution), and then perhaps multiple, but many fewer, differences
between non-human primates and humans (separated by a much shorter
period of evolutionary time).
Surprise! FOXP2 Is Almost Identical from Mouse to Human
Instead, they found that the cDNA sequences for the FOXP2 proteins
made in the mouse, the rhesus macaque, the great apes, and humans
were virtually identical (1). The amino acid sequence of this protein
had remained almost unchanged over 130 million years of evolution.
This remarkable sequence conservation implied that the protein was
involved in at least one very important function, a function so
important that few changes in the protein could be tolerated and
still be compatible with life. In fact, according to Dr. Paabo, FOXP2
turns out to be one of the most highly conserved proteins ever
identified.
Specifically, the cDNA sequence analysis indicated that there was
just one amino acid difference (out of 715 total) between the protein
found in the mouse and the protein found in the chimpanzee, gorilla,
and rhesus macaque (i.e., just one change in approximately 130
million years of evolution). The predicted protein sequence was
identical in these three non-human primates. Curiously, however, two
amino acid changes were seen between the protein in these animals and
the protein in humans (6 million years of evolution).
Quick Fixation and Selective Sweep
The fact that two changes to FOXP2 appeared to have become "fixed"
[link a, link b] (present in every member of the species) in the
human population in just 6 million years, whereas it took over 130
million years for just one change to have become fixed in the
chimpanzee, gorilla, and rhesus macaque versus the mouse, suggested
that one or both of the changes seen in humans conferred such a
strong selective advantage that the change(s) rapidly "swept" through
the population so as to become universally present in just a
relatively few generations. It was possible that one or both of the
mutations may have somehow provided the ability for much more
sophisticated communication, and that this advantage was so
significant as to lie at the basis of a "selective sweep" [link a,
link b].
Dr. Paabo suggested that one of the two changes is particularly
interesting in this regard, as it specifies an asparagine-to-serine
substitution at position 325 and would thus create a target site for
phosphorylation by protein kinase C [link a, link b]. Phosphorylation
by protein kinase C is a well-known mechanism for influencing the
activity of transcription factors, so this change might have caused a
significant change in the protein's activity.
Interestingly, the two amino acid changes that have become fixed in
humans both occur in the region of the protein that is coded for by
exon 7 of the FOXP2 gene, the same exon that is affected in the KE
family.
BACK TO TOP
Timing of Fixation May Link Language and Behavioral Advances
The next step taken by Dr. Paabo and his Max Planck colleague Dr.
Molly Przeworski was to attempt to determine the approximate time at
which the mutation(s) in the FOXP2 gene actually became fixed in the
human population. If this could be done, it might be possible to
correlate the time of fixation with an advance, something else in
human history, that might help explain the hypothetical advantage
underlying fixation by a sweep of positive selection [link a, link b].
For instance, if the time were found to coincide with the time at
which humans dramatically developed new behaviors (50,000 years ago),
this would lend support to the hypothesis that it was a quantum leap
in communication ability, such as the development of articulate
speech, that lay at the root of this dramatic change.
Statistical analyses by the Paabo team indicated that the mutations
might indeed have become fixed during the last 200,000 years of human
evolution. Although many assumptions underlie these analyses, it is
very unlikely that the observed selective sweep occurred farther back
in time than 200,000 years ago. Thus, the time of fixation
potentially overlaps with the appearance of modern human behaviors.
Based on the evidence presently available, Dr. Paabo suggests that it
is possible that, at the time that these mutations arose, humans had
perhaps already developed some primitive form of speech, and the new
mutations (one or both) in the FOXP2 gene somehow provided a new
capacity for sophisticated articulation of speech, and that this was
perhaps the final key step, in the development of advanced speech.
Future Work Will Target Function of FOXP2
Presently, teams led by Dr. Paabo, Dr. Fisher, and Dr. Monaco are
attempting to determine the function(s) of the FOXP2 protein. One
approach is to determine what other genes are turned on and off in
response to the presence of FOXP2. The researchers are investigating
this now using in vitro cell studies and microarray analysis.
There will surely be much more exciting news to report in the months
and years ahead.
Additional Product Information
Additional information on the Applied Biosystems products mentioned
in this article, as well as on other Applied Biosystems products, can
be obtained in the Product and Service Literature section of the
Applied Biosystems Web site.
References
1. Enard, W., Przeworski, M., Fisher, S.E., Lai, C.S.L., Wiebe, V.,
Kitano, T., Monaco, A.P., and Paabo, S., "Molecular Evolution of
FOXP2, a Gene Involved in Speech and Language," Nature 418: 869-872
(August 22, 2002). [Medline abstract].
2. Klein, R.G., "The Human Career: Human Biological and Cultural
Origins," University of Chicago Press; Chicago, Illinois; second
edition (1999).
3. Lai, C.S.L., Fisher, S.E., Hurst, J.A., Vargha-Khadem, F., and
Monaco, A.P., "A Forkhead-Domain Gene Is Mutated in a Severe Speech
and Language Disorder," Nature 413: 519-523 (October 4, 2001).
[Medline abstract].
4. Fischer, S.E., Lai, C.S.L., and Monaco, A.P., "Genetics of Speech
and Language Deficits," Annual Review of Neuroscience 26: 57-80
(2003). [Medline abstract].
5. Kaestner, K.H., Knochel, W., and Martinez, D.E., "Unified
Nomenclature for the Winged Helix/Forkhead Transcription Factors,"
Genes & Development 14(2): 142-146 (January 15, 2000). [Medline
abstract].
6. O'Neill, M.D., "First Language-Associated Gene Identified,"
BioBeat Online Magazine (May 22, 2002).
7. Krings, M., Stone, A., Schmitz, R.W., Krainitzki, H., Stoneking,
M., and Paabo, S., "Neandertal DNA Sequences and the Origin of Modern
Humans," Cell 90(1): 19-30 (July 11, 1997). [Medline abstract].
http://www.appliedbiosystems.com/biobeat/language/
December 15, 2003
Language by the plough
I finally read the paper on Indo-Europeans that gave support to
the "Anatolian Farmer" hypothesis. It was very compelling. I'm mildly
convinced.
Update: OK, here is the link zizka pointed to about linguists
criticizing the study. Follow the links within the link, and you can
find many attacks and pot-shots of the study.
A few points.
1) I agree that outside-of-speciality-people need to bone up on an
area they are "invading" before they get into using their techniques
in said area[1]. I've detected obvious historical and ethnological
errors in papers that study the genetic history of group X with
method Y, and it is pretty stupid seeing as how all you need is a
basic reference to double check your assertions and presuppositions
(they usually go along the lines of assuming that "general knowledge"
outside of a speciality of points in a speciality are the consensus,
when usually they are out of date by a few decades).
2) That said, why is more technique bad? Molecular biologists and
geneticists were told to stop talking about things they didn't know
about by palaeoanthropologists when they asserted from DNA evidence
that humans and other primates went they separate ways far more
recently than the consensus in the field they were invading. The
palaeoanthropologists had to eat eat crow when the fossils later
vindicated the wet lab guys. Today the two work in concert exploring
questions about the past.
3) Conflicts between different disciplines investigating the same
topic are fascinating and often lead to a more thorough
understanding, and sometimes a paradigm shift. If I remember
correctly, in the late 19th century biologists and geologists
asserted that the Earth must have been really old (for evolution and
geological processes), but physicists couldn't figure out a way that
the sun could produce the requisite energy for such an extended
period (they didn't the have weak and strong nuclear force, so no
fusion). Of course eventually the conflict disappeared when
physicists had a more fleshed out model of stellar evolution from
both observation and theoretical physics. Linguists of all people
should be open to methods and ways of thinking that shift paradigm,
their field after all has broken out of a niche in cultural
anthropology by expanding across other disciplines and importing
techniques and models. The general point, stay in your own area, has
some truth to it. Many natural scientists get very irritated
when "deconstructing theorists" decide to Study Their Way of Thinking
(or what not). But the problem is really that these people aren't
contributing anything to science, and are probably not that sincere
in forwarding scientific knowledge since they often don't believe it
is anything more than a belief-system a priori. For all their hubris
and ignorance, I think people who want to investigate linguistic-
historical questions through genetics and other methods that might
map well have their heart in the right place. Yeah, it sucks that the
mainstream press listens to them and accepts their pompous
pronouncements as if wisdom came into the world with evolutionary
biology (this is the general tone of some of the objections), but
reform and inform rather than revolt.
By the way, do linguists mostly reject Greenberg's theories about
Native American languages?. Its congruency to recent genetic evidence
is a mighty peculiar coincidence if it isn't the correct model (the
difference between "Na Dene" and "Amerinds").
fn1. Intellectual imperialism, done well, is a good thing. We are all
conscious beings, so I think a little bit of exportation of "rational
choice" from economics is OK. Similarly, we are all biological
creatures with pre-packages of instincts and impulses shaped by our
evolutionary history, so a little bit of exportation of "evolution"
from biology is OK. The problem happens when arrogance becomes
overwhelming. The physicists (like Francis Crick) who came into
biology reshaped the science with their methods and mind-set (also,
remember Linus Pauling, who made contributions all over the map and
was only just beaten out by Crick & Watson in the hunt for the
structure of DNA). Similarly, the inclusion of mathematically
oriented minds was crucial to the maturation of the "Neo-Darwinian
Synthesis." Cries of imperialism and the "inappropriateness" of
methods from physics or mathematics toward understanding biological
questions abounded in the early years, but I think today such folk
are remnants of the Old Order. The question is...are you a
reductionist? I am. So I think cross-fertilization is good, all
knowledge is the same in the end...do I sound like a consiliator or
what?
Posted by razib at 07:03 PM
http://www.gnxp.com/MT2/archives/001482.html
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