From today's NY times, and since some,
hi jackie for some unfathomable reason, hate going to the site, the first third of the article..
http://www.nytimes.com/2001/10/04/science/04LANG.htmlScientists Report Finding a Gene for Speech By NICHOLAS WADE
team of geneticists and linguists say they have found a gene that
underlies speech and language, the first to be linked to this uniquely
human faculty.
The discovery buttresses the idea that language is acquired and generated by
specific neural circuitry in the brain, rather than by general brain faculties.
The gene, which joins a handful known to affect human behavior, is of
particular interest because its role is to switch on a cascade of other genes in
the developing brain of the fetus. Biologists hope that by identifying these
"downstream" genes, they may be able to unravel the genetic basis of human
language.
The discovery may also help scientists answer the vital question of when
language evolved and whether the power it gave modern humans was the
primary reason they flourished and spread rapidly around the world.
Some scientists, however, say they believe the gene may be less specific to
language than it seems. So the new finding could simply fuel a longstanding
debate among linguists as to whether the brain handles language through
mechanisms specifically dedicated to the task or through a more general
system.
The new discovery is described in today's issue of Nature by Dr. Anthony P.
Monaco of the University of Oxford in England and colleagues.
The gene first came to light through study of a large family, half of whose
members have trouble pronouncing words properly, speaking grammatically
and making certain fine movements of the lips and the tongue. Asked to
speak a repetitive sound like "pataca pataca pataca," they will stumble over
each iteration. Outsiders have trouble understanding them when they speak,
and family members have difficulty understanding one another. Some of the
affected members, though not all, seem normal otherwise, suggesting that a
specific impairment of speech and language is the root of their problem.
The new study shows that all the affected members have inherited a
mutation, or variant piece of DNA, in a specific gene. The mutation affects a
single unit in the 6,500 units of DNA that make up the gene. So delicate is
the human genetic programming that this minuscule change suffices to
sabotage the whole faculty of speech and language.
The carriers of this variant gene resemble other people who have
impairments of language. They came to researchers' attention in 1990 only
because there were so many of them, all related and all living in the same
area of London. The family now has 29 members in three generations, 14 of
whom have the disorder.
The first linguist to study the family, Dr. Myrna Gopnik of McGill University
in Montreal, reported in 1990 that affected members were unable to change
the tense of verbs correctly, a finding that provoked considerable stir in the
linguistic world because it implied the existence of genes for grammar.
But in a later study of the family, Dr. Faraneh Vargha-Khadem of the
London Institute of Child Health identified a much wider range of speech and
language deficits, and some effects on general intelligence. The variant gene
"affects speech, but with knock-on effects in nonverbal ability," Dr.
Vargha-Khadem said.
OP
