LOT 1 - Introduction

8/6/2019 LOT 1 - Introduction

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Evolution of Language

Introduction


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Language and Speech

Are an important part of what makes

humans human


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Religion

Many cultures have

language origin myths

Either to explain why

we have language

Or to explain why we

have many languages


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Early speculation

Jespersens (1922) summarized:

Bow-wow theory

Pooh-pooh theory Ding-dong theory

Yo-he-ho theory

But his own alternative:

La-la theory


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In addition:


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The state-of-the-art in 1866

Evolution: Darwin 1858/1859

Neanderthal-skull: Schaaffhausen 1858

Linguistics: Stammbaum-theory, Schleicher ca.1853

Freud was 10 years old

Broca had discovered Brocas area in 1861


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Can we do better today?


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Topics

Evolution

Anatomy and Fossils

Genetics of Language Computer Models

Laboratory Experiments


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Carroll 2003

Gray &

Atkinson

2003

Darwin 1837

Evolution of Language and of

Languages


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Evolution

Both emergence of our capacity for

language and diversity of languages can

be seen as the outcome ofevolution


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Co-evolution

Co-evolution occurs when two systems evolve

and interact with each other

The systems influence each others fitness

Language and the capacity for language have co-evolved


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What exactly is evolution?

Three factors

Replication of information

Variation on this information

Selection on this variation

In the short term, these effects increase fitness Traits that increase replication are selected for


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An example

In the given

ecological context,

animals that can

eat higher food

have the advantage

transfer of information,

variation

selection


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Replication of Information (1)

Children must resemble their parents

Otherwise no direction to search

In language: need to be able to communicate with

parents

In biology: genes (DNA)

And perhaps to some extent: proteins and RNA

Difference between genotype (genes) and phenotype

(organism)


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Replication of information (2)

In biology genetic information is independent oflife experience Transfer from genotype to genotype

Phenotypic experience is not transferred

In language, only utterances are transferred, notlinguistic representations in the brain

This allows collective learning from experience Typical forcultural evolution

Lamarck (1809)


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Variation (1)

Variation is essential, otherwise one would not

explore the space of possibilities

In biology:

Recombination of genes

(diploid genes)

Crossover

Mutation

Essentially random


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Variation (2)

However, in language

(and culture)

variations can be

introducedconsciously, based on

experience

Making possible the

very rapid spread ofcultural innovations


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Selection (1)

Individuals that are in some respect betterare selected to create the next generation

But who determines what is better?

In biology fitness is by definition equal tonumber of offspring

But this is a post hoc measure, not an a priori

measure In biology, fitness depends on ecology


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Selection (2)

Selection is based on ability to createoffspring

Survival is a precondition for procreation

But other factors play a role

Sexual selection, among others

What does selection consist of in language? Acceptability to other language users?


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Variation/Selection

Functional changes Things that are easier to say are preferred by speakers

Things that are easier to understand are preferred by listeners

Contradictory forces

Ethnic identity Language is a very powerful factor in defining identity andsolidarity

Slang and jargon serve to distinguish oneself

Taboo Vocabularies can change rapidly when words can become taboo

Innovation Introduction ofnew words for new items

Or poetic innovation


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Complications

Multilingualism

Because a speaker uses multiple languages,these languages start to interfere

Famous example: Kupwar (India) Influences grammarand morphology

Loan words

W

ords for new objects, or words that havehigher prestige enterthe language

Influences lexicon


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More complications

Standards

Speakers adapt their speech to conform to acertain standard

Usually the standard has a certain prestige

Modern complications

Standardized education Mass media


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Evolution and tinkering

(Francois Jacob, Science 1977)

Evolution works with what is already there

This sometimes results in solutions that are less thanoptimal

Other terms are: Exaptation (cf. adaptation, the use of existing

structures for new purposes) Spandrels (Gould): Structures that have developed as

a side-effect of other adaptive functions, but that arenot necessarily adaptive themselves.


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Misconceptions about Evolution

Evolution always results in optimal

solutions

Evolution is goal-oriented

Evolution is an extremely slow process


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Evolution and teleology

Evolution is not teleological(goal directed) This is sometimes thought (e.g.

humans are the crown onevolution)

However there is somethingcalled the ratchet effect When a certain level of

complexity is reached, there isno turning back.

Example: once hard bodiedanimals evolve, soft bodiedones are at a strongdisadvantage (Ediacaran tolate pre-Cambrian transition)

Ediacaran fauna

Burgess shale fauna


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Evolution is slow?

Biological evolution tends to beslow

Because mutations are randomand most are bad

But in large populations,

adaptation can be quick Think antibiotic resistant bacteria

Some researchers claim evolutiongoes in fits and bursts

Punctuated equilibrium (Eldredgeand Gould 1972)

Cultural evolution can beextremely rapid

1977

2011


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Evolution Summary

Evolution is:

Transfer of information

Variation

Selection

Can be biological, cultural

There are important differences

Co-evolution also occurs The idea is simple, but the effects can be

very subtle.


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The evolutionary perspective (1)

Nothing in biology makes sense exceptin the light of evolution

Theodosius Dobzhansky (1973)

That does not mean that onlyan evolutionary perspective

is interesting Just that you need an evolutionary

perspective to understand ultimate causes


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The evolutionary perspective (2)

An evolutionary perspective is implicit in most

thinking about linguistic cognition

Consider:

A brain is necessary to

use language

But even flatworms have

brains

So what makes our brains

special, compared to otherbrains?

Dugesia sp.

Photo: Roberto Petracini


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Particulars of language evolution

Language needs strong cooperation

An interesting problem how this evolved

Co-evolution of culturally transmitted

language and biological adaptations crucial

A mutation for language is useless if no others

have it

Cultural system must already be present for

biological adaptation to work


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Evolution of language (2)

How can we study evolution of language?

No fossilized speech

and olderthan historical sources But data on: Modern human behavior

Fossils (Tuesdays class topic)

Animal behavior

Genetics (Wednesdays class topic) But there are questions we cannot answer

R. C. Lewontin (1998) The Evolution ofCognition: Questions wewill never answer


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Modern Language

Are there primitive languages?

No, not if native

No data on language evolution

But data on possibilities of language

But: pidgin-languages

Jargons, second language etc.

And creolisation

Oremergence of new language Nicaraguan sign language

Idea: proto-language

Bickerton


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When did language

emerge? Two extremes:

Late emergence (~30 000 years ago)

Early emergence (A. africanus)


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Symbolic explosion?

Symbolic culturalartifacts are found inNeandertals andH

. sapiens They are much olderthan previouslythought

T

hey appear anddisappearin the fossilrecord Second Bull, Lascaux cave

Photo: N. Aujoulat MCC-CNP


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Against late emergence

How can complex language evolve soquickly?

How does one explain biological

adaptations to language?

Homo sapiens started to spread muchearlierthan 5070 000 years ago

Would language have emerged in differentplaces?


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Deep history of language

Historical linguistics can reconstruct olderforms of a language (e.g. indo-european)

Traditional linguistics up to ~8000 years ago

But: Ruhlen claims proto-world

Very unlikely

Human expansion started about 150120 KAago

After this time all similarities are gone


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A summary of our knowledge

Language >100 000 years old

No primitive languages exist, and we know little abouthow they spread very long ago But we can observe emergence of new languages

That all have certain special properties

We can also observe incomplete languages

Language probably emerged as primitive proto-language Why is an interesting, but hard-to-answer question

How did it spread, how did it emerge? Cannot be reconstructed from fossils

But possible to model

And possible to compare to animal communication


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Comparative data (1)

Vocal behavior in other species can aid

understanding of speech

Precursors Primate vocal behavior the starting point

Parallel evolution

Song birds

Whales

Bats (?)


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Comparative data (2)

Interesting when trying to establish how

language can have evolved

Less interesting if only to establish

humans uniqueness

Sooner or later you will find similarbehavior in

other animals, or in other parts of cognition


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Hocketts

design-

features


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Ape Cognitive abilities

They can co-author

scientific papers


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They are, howeververy smart animals

They can learn impressive lexicons

Mostly directed towards requests Their abilities to combine words are disputed

No rules, no recursion


Sue Savage Rumbaugh & KanziPhoto: http://kanzi-superstar.blogspot.com/


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Chimpanzees use large sets of vocal signals

But mostly innate

Not discrete

Chimpanzees and gorillas use gestures

But dyadic

Some learned through

ritualization (not imitation)



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Gibbon song

Geissman, 2002


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Vocal culture in chimpanzees

(Crockford et al. 2004)

Some vocal learning in orangutans

Kuypers-Jrgens hypo-

thesis: control over mouth

but not over larynx

(Fitch 2010, 347-355)

Washington Post 4/3/2009

Bonnie


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Ability to cooperate is limited

But some cooperative hunting in chimps

And elaborate knowledge ofsocial hierarchy

Chimps appear to be much less altruistic

Some degree oftheory-of-mind

But much more limited than in humans



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Recursion Tamarin monkeys (Fitch & Hauser 2004): no

Starlings (Gentner et al. 2006): yes

Zebra finches (van Heijningen et al. 2009): no

Pirah: no

Brazilian Portuguese (university): yes

Brazilian Portuguese (illiterate): no

What is recursion anyway?


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Songbirds (1)

Doupe & Kuhl 1999


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Songbirds (2)

Many species Comparative studies possible

Crossing studies possible (wild and domesticatedbengalese finches)

Manipulation possible (fewer ethical concerns) Great diversity

Song complexity

Degree of learning

But different Neurologically Anatomically


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Humpback whale song

Payne & McVay (1971)


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Whales and dolphins

Humpback whales have complex, learned

songs

But these appear to be fixed per season

Some dolphin species show very complex

vocal behavior

Signature whistles

Hard to study, and relatively little is known


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Less well-known vocalizers

Pinnipeds

(Seals etc.)

Are capable ofimitation

For learning mating songs

Bats

Echolocation But also social vocalizations

Learned in some species

Phyllostomus hastatus


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Finally

Both biological and cultural evolution were

important for language evolution

Modern language tells us about ourabilities, notabout ourhistory (unfortunately)

Other species have complex vocal behavior,apes have many necessary precursors for

language, but no vocal imitation

Documents

LOT 1 - Introduction