Encyclopedia of Evolution.pdf - Online Reading Center

• Mutation of the FOXP2 gene impairs language ability.
Studies of the FOXP2 gene suggest that this gene originated
no more than 200,000 years ago. This suggests that earlier
hominins, as well as Neandertals (which were in an evolutionary
lineage distinct from that of modern humans) did
not have full language ability.
All humans appear to be descended from ancestors for
whom language ability was genetically encoded. Linguist
Noam Chomsky referred to the “deep structure” of language
in the human brain. Three lines of evidence suggest this conclusion:
• Children learn their first language, and often more than
one, with astonishing ease. It is much more difficult for
adults to learn a new language. In one notorious instance, a
girl was kept imprisoned in a closet in a Los Angeles apartment
until she was nearly an adult. Once she was discovered
and rescued, therapy has allowed her to learn and use
words, but she did not develop full grammatical ability.
• People with SLI (see above) have to think about each word
in each sentence, rather than developing a habit for language
construction. Anthropologist Myrna Gopick says
that it is as if these people have no native language—they
must learn their first language by rules just as normal
adults learn a second language.
• When people with mutually unintelligible languages are in
contact, they are often able to invent a pidgin language (the
word pidgin is pidgin for “business”) in which words easily
pronounceable in both languages are strung together with
minimal grammar. The language of the stronger trade partner,
or colonizer, is usually dominant; therefore pidgin English is
mostly English. Pidgin is never anybody’s first language. Pidgin
can then evolve into a full language, with grammar, at
which time it becomes a creole, which (like Jamaican) can be
a culture’s first language. After a generation of contact, the
pidgin language develops into a true creole, with grammatical
rules. Anthropologist Derek Bickerton, studying cultures
in Hawaii, found that it was children who invented the creole
grammatical forms while playing together, which suggests
that the invention of languages is an innate ability.
Primatologist Marc Hauser says that the first human
languages evolved from primate calls. Anthropologist Philip
Lieberman disagrees: He claims that language ability first
took the form of gestures instead of verbal speech. He points
out that apes are better at gesture communications than are
other animals. Furthermore, a mental association between
language ability and gesture ability is suggested by the fact
that Parkinson’s disease, which severely limits gestures, also
limits the ability of the people to construct regular verbs—
even though they can recall irregular verbs from memory.
Finally, humans seem to learn sign languages, which include
complete sets of grammatical rules, as readily as verbal languages.
At several places independently around the world,
groups of deaf children have invented their own sign languages
without instruction.
Language ability is such a complex adaptation that there
must have been very strong selection for it, once it had devel-
language, evolution of
oped in rudimentary form (see gene-culture coevolution).
Once humans had evolved the ability to use language,
any individuals with less language ability would have been at
a distinct disadvantage.
The origin of language seems to be inextricably tied with
the origin of intelligence (see intelligence, evolution of).
The Wernicke’s and Broca’s areas aside, intelligence is necessary
for humans to have something to say. Some evolutionary
scientists, such as Robin Dunbar, have noted a positive correlation
between the size of the neocortex (the most recently
evolved part of the brain) and the size of social groups. Smallbrained
primates get to know each other by social grooming,
in which one will pick the parasites out of the fur of another.
As social groups become larger, greater intelligence is needed
to remember who is who. This can be important because
an individual must remember who is a friend and who is an
enemy, and to keep track of which individuals are not trustworthy
reciprocators of altruism (see altruism). Complex
vocal communications, and eventually language, substituted
for grooming as a way of communication in large groups,
and also as a medium for sharing gossip about different individuals—their
characteristics, their allegiances.
Early 20th-century speculations about the origin of language
included the following theories, which were given popular
names, as recorded by linguists such as Mario Pei and
Charlton Laird. According to these theories, languages began:
• as an imitation of animal communication: the bow-wow
theory
• as emotional exclamations of fear, pain, or lust: the poohpooh
theory
• as signals to help coordinate teamwork: the yo-heave-ho
theory
• as song and dance: the sing-song theory
• or as onomotopoeia: the ding-dong theory
Most of these theories failed to take into account the
incredible complexity of primitive languages, which is surprising
since this pattern was well documented by the early
20th century. Not just some but all primitive languages that
have been studied have astounding complexity. Within historical
times, languages have simplified as they have been
used more and more for commerce. This pattern of simplification
through time from primitive complexity has been used
by some religious writers (see creationism), including this
author in his earlier life as a creationist, as evidence for the
Tower of Babel theory. This is the Genesis story that God
created the complexity of languages, then scattered people all
over the world, from a Mesopotamian origin. The problem
with this proposal, aside from its lack of supporting evidence,
is that no truly primitive languages exist, therefore the current
linguistic trend of simplification cannot lead scientists to
understand the origin of language. What this trend does indicate
is that the forces that selected for the origin of language
ability were not the same as the ones operating today. Extrapolation
into the historical past is valid; extrapolation into the
evolutionary past is not. Modern English is much simpler
than its immediate precursors such as Old English and Anglo-
Saxon, and all the Romance languages (Spanish, French,