Psychology 337

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Psychology 337

• Section 1 BackgroundA. Introduction

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LANGUAGE

• LANGUAGE FANCIEST CAPABILITY OF LIVING FORMS
• MAIN OBVIOUS DEFINING BEHAVIOR OF HUMANS WHO ARE
  THE MOST ADVANCED SPECIES
  
• ALLOWS UNIVERSAL COMMUNICATION OF MEANINGS
• ANOTHER NEW HUMAN STEP MATERIAL CULTURE HUGE
  SIGNIFICANCE
  
• MOST RECENTLY (5,000 YA) WRITTEN LANGUAGE

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LANGUAGE PLUS CULTURE

• GIVE STUPENDOUS INTERGENERATIONAL KNOWLEDGE
  TRANSMISSION
  
• A NEW FORM OF EVOLUTION WITH COMPOUND INTEREST
• WE STAND ON THE SHOULDERS OF GIANTS (NEWTON)

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PSYCHOLINGUISTICS

• SCIENTIFIC STUDY NEW (1962) AND PRELIMINARY
• PSYCHOLINGUISTICS DEFINITION THE SCIENCE OF
  HUMAN LANGUAGE PRODUCTION, COMPREHENSION AND
  ACQUISITION (LEVELT, 1989)
  
• SPEECH - LANGUAGE DISTINCTION SPEECH IS THE
  NORMAL PRIMARY MEDIUM OF LANGUAGE. (NOTE ALSO
  SIGN LANGUAGE OF THE DEAF) READING AND WRITING
  CONSTITUTE A SECONDARY (TAUGHT) MEDIUM

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• THE COURSE IS ORGANIZED AROUND A FUNDAMENTAL
  DIFFERENCE OF OPINION BETWEEN TWO SCHOOLS OF
  THOUGHT 1.FORMALISM AND 2.NEODARWINIANISM
  
• 1.FORMALISM
• ALTERNATELY
• ESSENTIALISM, RATIONALISM, OBJECTIVISM. LONG
  HISTORY A.PLATO, B.DESCARTES, AND C. CHOMSKY
  
• THESISTHE FORM OF THINGS IS A'PRIORI

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• A) PLATO THINGS HAVE ESSENCES (TRIANGLE)
• B) DESCARTES ALL KNOWLEGE AMENABLE TO
  MATHEMATICALLY DRIVEN REASON (OF HUMANS)
  
• C) CHOMSKY LANGUAGE RESULTS FROM INNATE
• UNIVERSAL GRAMMAR

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• 2.NEODARWINIANISM IS A MODERN CONSENSUS ON
  DARWIN'S THEORY OF EVOLUTION BY NATURAL
  SELECTION.
  
• THESIS FORM OF ALL LIVING THINGS ARISES FROM
  SUCCESSFUL FUNCTION (SURVIVAL OF THE FITTEST)
  

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THE 2 SCHOOLS OF THOUGHT
1. FORMALISM LANGUAGE GENETICALLY SPECIFIED
EXPERIENCE TRIVIAL.
2. NEODARWINIANISM INTERACTION WITH WORLD
CRUCIAL
(INCLUDING CULTURE).
Environment
Environment
Organism
Organism
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• THESE TWO VIEWS ARE INCOMPATIBLE, AND IN THE
  ABSENCE OF OTHER ALTERNATIVES, ONE OF THEM IS
  PROBABLY RIGHT.
  
• I THINK DARWIN WAS RIGHT
• THE FORCE OF THE FORMALIST ARGUMENT ABOUT
  LANGUAGE COMES MAINLY FROM POINTING TO LINGUISTIC
  PHENOMENA, LARGELY IN LANGUAGE ACQUISITION, THAT
  AREN'T PRESENTLY UNDERSTANDABLE IN ANY OTHER WAY
  THAN INVOKING A'PRIORI FORM.

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BEWARE HELMONTS ERROR

• BUT NOT UNDERSTANDABLE DOESNT MEAN IT MUST BE
  APRIORI
  
• CONSIDER HELMONTS ERROR
• HE DID AN EXPERIMENT THAT SHOWED THAT TREES
  GROW BY WATER ALONE
  
• HE LEFT OUT 2 CRUCIAL BUT NON-OBVIOUS
  VARIABLES
  
• SUNLIGHT AND AIR

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SELF ORGANIZATION

• ANOTHER POSSIBILITY FOR THE CREATION OF FORM.
• DEFINITION A SELF ORGANIZING SYSTEM IS ONE IN
  WHICH SOME KIND OF HIGHER ORDER PATTERN EMERGES
  FROM THE INTERACTIONS OF MULTIPLE SIMPLE
  COMPONENTS WITHOUT THE BENEFIT OF A LEADER,
  CONTROLLER OR ORCHESTRATOR. (CLARK, 1997)
• SELF-ORGANIZATION IS FOUND IN PHYSICAL AND
  BIOLOGICAL WORLDS
  

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EXAMPLES OF SELF-ORGANIZATION

• EXAMPLE 1 HEXAGONAL CELLS IN BEEHIVES
• (SEE READING ON THE CAUSES OF FORM IN NATURE)
• EXAMPLE 2 ELEVATOR PRINCIPLE OF VOWEL SYSTEMS

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MY CONCLUSION

• AS EVERY OTHER MAJOR ASPECT OF LIFE FORMS EVOLVED
  BY NATURAL SELECTION, LANGUAGE PROBABLY DID TOO.
  
• BUT WHOEVER IS RIGHT, THE CONTEST BETWEEN THESE
  APPROACHES IS A MAJOR ASPECT OF CURRENT COGNITIVE
  SCIENCE.
  

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BRAIN-LANGUAGE FOCUS

• CROSS-SPECIES COMPARISON OF BRAIN EVOLUTION
  TOGETHER WITH BEHAVIORAL EVOLUTION GIVES A MORE
  COMPLETE EVOLUTIONARY PICTURE.
  
• HELPS COMPENSATE FOR THE FACT THAT LANGUAGE
  DOESN'T FOSSILIZE.
  
• OTHER PRIMATES (PROSIMIANS, MONKEYS AND APES) CAN
  BE TAKEN TO BE SIMILAR TO OUR ANCESTORS.

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BASIC PROPOSITION OF THIS COURSE

• HUMAN LANGUAGE IS UNIQUE, BUT NEVERTHELESS MUST
  HAVE EVOLVED FROM NONLINGUISTIC CAPABILITIES
  (A'PRIORI FORM IS ALSO UNEXPLAINABLE FORM)
  
• FIGURING OUT HOW WILL ULTIMATELY LEAD TO THE BEST
  UNDERSTANDING OF PSYCHOLINGUISTICS. SO WE SHOULD
  TRY TO DO IT
  
• THIS IS THE "ULTIMATE CAUSES" PERSPECTIVE OF MAYR

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Psychology 337

• Section 1 BackgroundB. Language Definition

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LANGUAGE DEFINITION

• DEFINITION (SPOKEN) FEWER THAN 150 SOUNDS
  (CONSONANTS AND VOWELS MODE 30. RANGE 11-141)
  WHICH ARE INDIVIDUALLY MEANINGLESS, ARE
  CONCATENATED (PUT TOGETHER), NOT IN ALL POSSIBLE
  WAYS, TO PRODUCE SOME HUNDREDS OF THOUSANDS OF
  MEANINGFUL MORPHEMES (MEANING UNITS WORDS OR
  PARTS OF WORDS) WHICH HAVE MEANINGS THAT ARE
  ARBITRARILY ASSIGNED, AND THEY ARE CONCATENATED
  BY RULE TO YIELD AN INFINITE SET OF SENTENCES,
  HAVING MEANINGS THAT CAN BE DERIVED."
• (ROGER BROWN - WITH MODIFICATIONS)

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LANGUAGE4 IMPORTANT PROPERTIES

• 1. ARBITRARINESS LACK OF A PRINCIPLED RELATION
  BETWEEN A CONCEPT AND THE SOUND PATTERN THAT GOES
  WITH IT.
  
• ENGLISH "CHURCH" FRENCH "EGLISE" ETC
• CONTRAST THIS WITH ICONICITY SIGNAL RESEMBLE
  CONCEPT. E.G. SOME SIGNS IN SIGN LANGUAGE
  
• HISTORY OF THOUGHT ON THIS PROBLEM
• PREDARWINIAN IN "ADAMIC LANGUAGE" THERE WAS A
  PRINCIPLED RELATION BETWEEN CONCEPTS AND SOUND
  PATTERNS. THEN CAME THE TOWER OF BABEL.
  
• DARWIN FORMS MUST ARISE FROM USE

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• LANGUAGE IS NOT ENTIRELY ARBITRARY
• AND IT COULDNT HAVE STARTED ARBITRARY
• 1. ONOMATOPOEIA
• 2. PHONETIC SYMBOLISM LOW FREQUENCY SOUNDS FOR
  BIG OBJECTS AND VICE VERSA
  
• 3. "MAMA" CONTRIBUTED BY BABIES
• BUT THIS DOESN'T ACCOUNT FOR MUCH

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• THERE MUST HAVE BEEN A LOT OF INVENTION OF WORDS
  BY CHIEFS, WITCH DOCTORS ETC
  
• ALSO METAPHOR MUST HAVE PLAYED EVENTUALLY PLAYED
  A HUGE ROLE. E.G. CONCRETE TO ABSTRACT
  
• MY THEORY THE INITIAL RAW MATERIAL FOR WORDS WAS
  LIKE THE BABBLING OF BABIES
  
• IN FACT THE VERY FIRST WORDS MIGHT HAVE BEEN
  INVENTED IN A BABY TALK SITUATION
  
• ONE IMPORTANT IMPLICATION OF ARBITRARINESS
• INFANTS MUST LEARN THE WORDS OF LANGUAGE X
  ONE-BY-ONE - THE LINKAGES CANT BE INNATE
  

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• 2. DISPLACEMENT
• THE SUBJECT MATTER OF LANGUAGE IS NOT RESTRICTED
  TO THE HERE AND NOW
  
• WE CAN TALK ABOUT OTHER PLACES AND TIMES, AND
  EVEN ABOUT THE NON-REAL
  
• THIS SETS LANGUAGE APART FROM OTHER OTHER FORMS
  OF ANIMAL COMMUNICATION

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• 3. DUALITY TWO LEVELS OF ORGANIZATION
• A. MEANINGLESS SOUNDS INTO MEANINGFUL MORPHEMES
  (PHONOLOGY)
  
• B. MORPHEMES INTO SENTENCES

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• 4. PRODUCTIVITY CONCATENATION AT EACH OF THE TWO
  LEVELS, EACH WITH RULES OF COMBINATION.
  (COMBINATION AN ORDERED SEQUENCE)
  
• EXAMPLES IN ENGLISH
• PHONOLOGY (3 SOUNDS - 3 POSSIBILITIES)
• "CAT", "TACK", "ACT"
• SYNTAX "JOHN HIT MARY" "MARY HIT JOHN" OR
  "BLIND VENETIAN" "VENETIAN BLIND"
  

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• MORE ON PRODUCTIVITY
• NOTE THE POWER OF COMBINATION TO "PRODUCE (OR
  GENERATE) LARGE NUMBERS OF ENTITIES.
  
• THE NUMBER OF POSSIBLE COMBINATIONS OF N UNITS
  USED ONCE IN EACH SET IS N! (N FACTORIAL)
  EXAMPLES FOLLOW.
  
• 3 UNITS A B C
• COMBINATIONS (6) ABC ACB BAC BCA CAB CBA
• 3! 3 X 2 X 1 6
• 4! 4 X 3 X 2 X 1 24.
• 10! 10 X 9 X 8 ... 3.628.800 ETC

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• NOW IMAGINE THE POSSIBILITIES IF YOU COULD USE
  EACH UNIT MORE THAN ONCE, IN SETS OF VARIOUS
  SIZES, NOT JUST SIZE 3 AS IN THE ABOVE EXAMPLE.
  
• THUS, HUNDREDS OF THOUSANDS OF MORPHEMES ARE
  POSSIBLE.
  
• AN INFINITE NUMBER OF SENTENCES IS MADE
  MATHEMATICALLY POSSIBLE BY MEANS OF RECURSION THE
  SAME STRUCTURE CAN RECUR IN A SINGLE SENTENCE.
  TAKE THE FOLLOWING EXAMPLE

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• 1.This is the house that Jack built.
• 2.This is the mouse that lived in the house that
  Jack built.
  
• 3.This is the rat that worried the mouse that
  lived in the house that Jack built."
  
• 4.This is the cat that ...etc.
• WITH EACH NEW "THAT" WHICH OCCURS SUBSEQUENT TO
  SENTENCE 1, A RELATIVE CLAUSE RECURS.
  
• THOUGH WE DON'T USUALLY DO MANY RELATIVE CLAUSES
  AT A TIME IN ONE SENTENCE, ITS EASY TO SEE, FROM
  THE PROPERTIES OF COMBINATION THAT WE CAN PRODUCE
  AN INDEFINITE NUMBER OF SENTENCES, AND WHY
  HOCKETT SAID THAT MOST SENTENCES THAT ARE UTTERED
  WERE NEVER UTTERED BEFORE AND WILL NEVER BE
  UTTERED AGAIN.

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• NOTE THE CONSEQUENCES OF THIS FOR OUR
  UNDERSTANDING OF LANGUAGE ACQUISITION.
  
• INFANTS COULDN'T LEARN EACH OF THEIR INDIVIDUAL
  SENTENCES (E.G. BY IMITATION). THEY MUST LEARN
  RULES FOR SENTENCE CONSTRUCTION.
  
• AN ANALOGY HAS BEEN MADE BETWEEN LANGUAGE
  STRUCTURE AND GENETIC STRUCTURE.
  
• GENES (100,000 IN HUMANS) ARE MADE UP OF DNA
  WHICH CONSISTES BASICALLY OF UNLIMITED
  COMBINATIONS OF JUST FOUR COMPOUNDS ADENOSINE,
  THYMIDINE, CYTOSINE AND GUANINE.
• THERE IS ALSO AN ANALOGY WITH THE ELEMENTS OF
  CHEMISTRY.
  

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THE PARTICULATE PRINCIPLE

• THE PRINCIPLE BY WHICH UNITS ARE CONCATENATED
  INTO FORMS THAT HAVE PROPERTIES OF THEIR OWN,
  OVRE AND ABOVE THE PROPERTIES OF THE UNITS THAT
  COMPOSE THEM IS KNOWN AS THE PARTICULATE PRINCIPLE

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Psychology 337

• Section 1 BackgroundC. Evolution

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COMPARISON OF LANGUAGE WITH VOCAL COMMUNICATION
IN OTHER PRIMATES

• OTHER PRIMATES HAVE A REPERTOIRE OF ABOUT 30
  CALLS WITH ONE CALL PER MEANING UNDER NATURAL
  CONDITIONS (WE WILL DEAL WITH ATTEMPTS TO TEACH
  OTHER PRIMATES LANGUAGE LATER).
• THUS, OTHER PRIMATES HAVE NEITHER DUALITY NOR
  PRODUCTIVITY. LITTLE DISPLACEMENT EITHER.
  

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• UNLIKE HUMANS, EACH OF WHOM LEARNS THE LANGUAGE
  OF THEIR PARTICULAR COMMUNITY, OTHER PRIMATES,
  SEEM TO HAVE NEGLIGIBLE VOCAL LEARNING CAPACITY.
  
• (THIS IS SHOWN BY CROSS-FOSTERING MONKEY INFANTS
  OF DIFFERENT SPECIES THE INFANTS DO NOT LEARN
  THE CALLS OF THEIR FOSTER PARENTS.)
  
• THUS TO ME, THE MAIN PROBLEM IN THE EVOLUTION OF
  LANGUAGE IS TO EXPLAIN HOW WE EVOLVED FROM
  ANIMALS THAT DID NOT HAVE DUALITY, PRODUCTIVITY
  OR DISPLACEMENT IN THEIR COMMUNICATION SYSTEM TO
  ANIMALS THAT DO, ACQUIRING A GREATER LEARNING
  CAPACITY AND MORE INDEPENDENCE OF COMMUNICATIVE
  SIGNALS FROM EMOTIONAL STATES IN THE PROCESS.

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WHAT DO ANIMALS HAVE?

• BUT NOTICE THAT MANY OTHER ANIMALS HAVE
  NONLINGUISTIC COGNITIVE CAPACITIES THAT POWER
  LANGUAGE IN HUMANS.
  
• TO TAKE SOMETHING THAT OCCURS IN HUMAN AND OTHER
  PRIMATE ENVIRONMENTS, FECES IS SOMETHING THAT ALL
  PRIMATES HAVE A CONCEPT OF, OR A SPECIFIC
  CATEGORY FOR. WORDS MUST ATTACH TO SUCH
  NONLINGUISTIC CONCEPTS OR CATEGORIES TO HAVE
  MEANING.

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• SECOND, LINGUISTIC EVENTS ARE TYPICALLY TAILORED
  TO THEIR SOCIAL ENVIRONMENT ("PRAGMATICS" IS THE
  STUDY OF THIS) BUT BEHAVIOR IN GENERAL, IN
  HUMANS, AND OTHER PRIMATES IS TYPICALLY TAILORED
  TO THE SOCIAL ENVIRONMENT.
• THUS, LANGUAGE MUST INTERFACE WITH NONLANGUAGE IN
  TWO MAIN WAYS, AND WE MUST STUDY HOW.
  

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EVOLUTION

• DARWIN'S THEORY OF EVOLUTION BY NATURAL SELECTION
  IS AS POWERFUL AND IMPORTANT AS ANY THEORY IN THE
  HISTORY OF SCIENCE (E.G. NEWTON'S EINSTEIN'S).
  
• IT PROVIDES A POSSIBLE EXPLANATION (EITHER
  ALREADY AVAILABLE OR IN PRINCIPLE) OF THE ORIGIN
  AND NATURE OF ALL LIVING FORMS. (THEREFORE - IN
  PRINCIPLE - FOR LANGUAGE).

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OPINIONS ON THE THEORY

• 1. "HISTORICAL PERIODS ARE DOMINATED BY DISTINCT
  SETS OF IDEAS. GREEK PHILOSOPHY, CHRISTIANITY,
  RENAISSANCE THOUGHT, THE SCIENTIFIC REVOLUTION,
  AND THE ENLIGHTENMENT ARE SETS OF IDEAS THAT
  DOMINATED THEIR HISTORICAL PERIOD. ... THE
  CHANGES ... ARE OFTEN REFERRED TO AS REVOLUTIONS.
  THE MOST FAR REACHING OF ALL THESE INTELLECTUAL
  UPHEAVALS WAS THE DARWINIAN REVOLUTION."
• ERNST MAYR - MOST EMINENT LIVING EVOLUTIONARY
  THEORIST
  

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• 2. ON DARWIN - "A BRILLIANT MIND, GREAT
  INTELLECTUAL BOLDNESS, AND AN ABILITY TO COMBINE
  THE BEST QUALITIES OF A NATURALIST-OBSERVER,
  PHILOSOPHICAL THEORETICIAN, AND EXPERIMENTALIST -
  THE WORLD HAS SO FAR SEEN SUCH A COMBINATION ONLY
  ONCE, AND IT WAS IN THE MAN CHARLES DARWIN.
• MAYR
• 3. DARWIN'S THEORY -"OUTLINED THE ESSENTIAL
  FEATURE OF THE SECRET OF LIFE."
  
• FRANCIS CRICK - NOBEL PRIZE WINNER FOR
  CO-DISCOVERY OF DNA STRUCTURE
  

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• 4. "THIS BOOK IS WRITTEN IN THE CONVICTION THAT
  OUR OWN EXISTENCE ONCE PRESENTED THE GREATEST OF
  ALL MYSTERIES, BUT THAT IT IS A MYSTERY NO LONGER
  BECAUSE IT IS SOLVED. DARWIN AND WALLACE SOLVED
  IT ... I WROTE THIS BOOK BECAUSE I WAS SURPRISED
  THAT SO MANY PEOPLE SEEMED NOT ONLY UNAWARE OF
  THE ELEGANT AND BEAUTIFUL SOLUTION TO THIS
  DEEPEST OF PROBLEMS BUT, INCREDIBLY, IN MANY
  CASES ACTUALLY UNAWARE THAT THERE WAS A PROBLEM
  IN THE FIRST PLACE.
• RICHARD DAWKINS - AUTHOR OF THE BEST MODERN
  DEFENSE OF THE THEORY
  
• 5. "IF I WERE TO GIVE AN AWARD FOR THE SINGLE
  BEST IDEA ANYONE HAS EVER HAD, I'D GIVE IT TO
  DARWIN, AHEAD OF NEWTON, EINSTEIN, AND EVERYONE
  ELSE". DENNETT, 1995, P 21.

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PRESENT STATUS OF THE THEORY

• IN SPITE OF ITS MERITS IT IS OFTEN IGNORED,
  DISPUTED AND MISUNDERSTOOD.
  
• TWO REASONS FOR THIS
• 1. IT CONTRADICTS RELIGIOUS IDEAS. GALLUP 50
  OF AMERICANS (25 OF COLLEGE GRADUATES) BELIEVE
  THE CREATION SCENARIO ("1 NATION UNDER GOD").
  
• 2. IT OPPOSES CONCEIT. MOST HUMANS TEND TO BE
  ANTHROPOCENTRIC - THEY WANT TO BELIEVE THEY ARE A
  CLASS APART FROM ANY OTHER LIFE FORM, (AND
  DESCARTES HAS ENCOURAGED THEM).

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• THERE CERTAINLY SEEM TO BE GOOD REASONS TO
  BELIEVE WE ARE DIFFERENT.
  
• BUT THE QUESTION IS HOW DID WE GET DIFFERENT.
• EVOLUTION IS A FACT AS WELL DOCUMENTED AS
  ANYTHING ELSE WE CALL A FACT.
  
• DENNETT ANYONE WHO DOESN'T KNOW THIS IS SIMPLY
  IGNORANT.
  

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TWO FACTS MAKE EVOLUTION A FACT

• 1. FOSSIL RECORD SIMPLER FORMS IN LOWER
  STRATA MORE COMPLEX BUT OBVIOUSLY RELATED FORMS
  IN HIGHER STRATA.
  
• 2. RADIOACTIVE DATING TECHNIQUES SHOW AGE OF
  STRATA - LOWER STRATA EARLIER.
  
• THEREFORE MORE COMPLEX FORMS EVOLVED FROM MORE
  SIMPLE FORMS IN THE TIME DOMAIN.
  

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DARWINS TWO CONTRIBUTIONS

• 1. HE PRESENTED MOUNTAINS OF EVIDENCE FOR THE
  FACT OF EVOLUTION
  
• THIS FIRST CONTRIBUTION HAS BEEN BASICALLY
  ACCEPTED IN THE SCIENTIFIC COMMUNITY ALMOST FROM
  THE TIME HE MADE IT (1859 "THE ORIGIN OF
  SPECIES".)
• 2. HE SUGGESTED A MECHANISM FOR EVOLUTION -
  NATURAL SELECTION.
  
• THIS HAS REMAINED CONTROVERSIAL BUT IS NOW FOR
  THE MOST PART ACCEPTED, AND THERE IS NO VIABLE
  ALTERNATIVE.
  

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WHAT IS NATURAL SELECTION?

• SHORTHAND "SURVIVAL OF THE FITTEST" (SPENCER).
• MEMBERS OF A SPECIES EXHIBIT VARIATION IN MANY
  ATTRIBUTES (E.G HEIGHT) (DISTRIBUTION OF
  VARIATION NORMAL CURVE).
  
• MEMBERS IN A CERTAIN SUB-RANGE OF THE RANGE OF
  VARIATION MAY BE BETTER ABLE TO RESPOND TO
  ENVIRONMENTAL PRESSURES THAN OTHERS, AND
  CONSEQUENTLY REPRODUCE MORE OFFSPRING THAN
  OTHERS. OVER A NUMBER OF GENERATIONS THIS TREND
  WILL LEAD TO NEW SPECIES.

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EXAMPLES

• 1. TALLER GIRAFFES CAN FEED OFF LEAVES HIGHER
  IN TREES.
  
• 2. MOTHS CHANGE COLOR TO MATCH TREES AS
  POLLUTION LEVELS CHANGE (CAMOUFLAGE).
  
• 3. FOLLOWING FOOD SHORTAGES ON THE GALAPAGOS
  ISLANDS, SPECIES OF DARWIN'S FINCH WITH BEAK
  CHARACTERISTICS BEST SUITED TO EXPLOITING
  REMAINING FOOD HAD RELATIVELY MORE OFFSPRING IN
  THE NEXT GENERATION (SEE GRANT) THIS IS ON-LINE
  EVOLUTION.

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KEY TERMS

• 1.ENVIRONMENTAL PRESSURES "SELECTION PRESSURES"
• 2. SUCCESSFUL CHANGES "ADAPTATIONS"

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VARIATION (ESSENTIAL)

• 2 SOURCES
• 1. MUTATIONS (CHANGES IN GENES) MOST ARE FATAL.
  LARGE CHANGES IMPOSSIBLE BECAUSE CHANGES MUST BE
  COMPATIBLE WITH EXISTING PROPERTIES FOR THE
  RESULT TO WORK.
• 2. SEXUAL REPRODUCTION. (MORE IMPORTANT) GIVES
  NEW MIXES OF GENES.
  

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The Origin of Species(The modern theory of
biological evolution)
Propagation
Genetic Processes
Variation
Natural Selection
Species
Adaptations
E.g. Mutation, Sex
Selective Pressure
Anatomy Behavior
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THREE PROBLEMS IN UNDERSTANDING THE THEORY
(CRICK)

• 1. HARD TO CONCEIVE THE SLOWNESS OF THE TIME
  SCALE - BIG EFFECTS BY SMALL STEPS. (NOTE HOYLE'S
  PROBLEM OF BOEING 707S FROM JUNKYARDS) BUT,
  SIZEWISE, FROM A MOUSE TO AN ELEPHANT BY 1 1/2
  OZ. STEPS WOULD TAKE 12.000 5 YEAR GENERATIONS
  -HARDLY ANY TIME IN EVOLUTIONARY TERMS.

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• 2. Q HOW CAN RANDOM VARIATION GIVE COMPLEX
  STRUCTURE? A. VARIATION IS RANDOM BUT SELECTION
  IS NOT.
  
• 3. PROBLEM HOW COULD EACH STEP TOWARDS AN "ORGAN
  OF EXTREME COMPLICATION AND PERFECTION" (E.G. THE
  EYE) BE ADAPTIVE? 1 VISION IS BETTER THAN NO
  VISION.

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3.8
EVOLUTION OF LIFE FORMS (LEWIN, CH 1)
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PRIMATE EVOLUTION (LEWIN, CH 4)
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Prosimians
Aye aye
Red-fronted lemur
Tarsier
Slow loris
Sifaka
Ring-tailed lemur
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Gibbons Siamangs
Pigmy marmoset
Golden-lion tamarin
Chimpanzee
Squirrel monkey
Baboon
Orangutan
Mountain gorilla
Spider monkey
Japanese macaque
Colobus monkey
Rhesus macaque
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(possibly 1.2 mya)
HUMAN EVOLUTION (LEWIN, CH 7)
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The Hominid Family Tree

• Question When did the hominid family tree split
  from a common ancestor with chimpanzees?
  
• DNA dating estimate 5-7 mya.
• Recent fossil evidence points more to 7 mya.

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Bipedalism

• Bipedalism with upright posture is considered to
  be the main initial defining property of humans.
  
• It has been considered to have been selected to
  allow early hominids to see better on the
  savanna, to facilitate long journeys, to give
  more protection of the body from the sun, and to
  allow hominids to carry food and weapons.
• All but the last of these has been ruled out by
  recent findings suggesting bipedalism in hominids
  living in the forest close to 5 mya.

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Bipedalism and I.Q.

• Another surprise has been that while logic
  suggests the bipedalism must have been associated
  with an increase in the brain-size to body-size
  ratio--the Encephalization Quotient or E.Q--brain
  size increases didnt begin before Homo Habilis
  at about 2 mya.

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Lumpers vs Splitters

• Paleontologists can be divided in lumpers,
  postulating as few forms as possible, and
  splitters, postulating more forms.
  
• Recent findings suggest more forms than before.
  But there is some evidence of a major split into
  2 lines The Robust line with animals with huge
  prognathous jaws and small brains, and the
  Gracile line with smaller less protruding jaws,
  beginning with Homo Habilis.
• It is thought that the evolution of tool use took
  the burden of food processing off the jaws, but
  the earliest tools have been found at Robust
  sites.

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Out of Africa

• Recent evidence suggests that there have been a
  number of migrations out of Africa, starting
  close to 2 mya and ending with the last one at
  only about 80 tya. The main homo line in Africa
  at about 2 mya is now called Ergaster rather than
  Erectus.
• The term Erectus is reserved for the migrating
  populations, up to about 300 tya, when modern
  Homo Sapiens - our species - first arose.

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Tool Use

• Tool use was taken to be a major defining
  property of humans, but many other animals are
  now known to use tools.
  
• Jane Goodalls chimpanzees, who take leaves off
  twigs before thrusting them into termite mounds
  to get termites, also manufacture tools. Now the
  only defining human characteristic relative to
  tools is that only we make machine tools (tools
  to make tools).

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Brain Size

• The rate of increase in brain size in the last 2
  mya (unprecedented in other life forms) is
  presently not well understood. It cant be tied
  to developments in tool manufacture and use,
  because they go in fits and starts.
• One suggestion Its related to dietary
  improvements involving tubers.
  
• Another suggestion Its related to
  survival-related increases in social
  intelligence. E.g Theory of Mind.
  
• Most recent suggesting It is directly produced
  by genetic changes.

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Use of Fire

• The use of fire, now dated to 1.2 mya (Brain) was
  an important development for protection from
  predation, food preparation and nutrition, and
  the probable socio-cultural developments that
  resulted from groups sitting around camp fires
  for long periods of time.

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When Language Evolved

• Two extreme lines of thought
• 1. Paleontologists (stone and bone people, e.g.
  Holloway) think it might have evolved in Homo
  Habilis, because there is endocast evidence for a
  Brocas area in this taxon.
• 2. Anthropologists (E.G. Klein) think language
  might have evolved in the last 50 tya, because it
  must have accompanied the apparent cultural
  explosion occurring at about this time, judging
  from new tools, cave drawings, figurines, burial
  of the dead with bodily ornaments etc (e.g. at
  Lascaux in southern France and Altamira in
  northern Spain).

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Mono- or Polygenesis of Language

• There is some consensus that there might have
  been a single first language evolving in Africa
  before 80 tya, and subsequently spreading to the
  rest of the world.

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ENCEPHALIZATION QUOTIENT (DONALD, CH 4)
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EVOLUTION OF COMMUNICATION USE OF MEDIA

• OLFACTORY- IMPORTANT IN NOCTURNAL MAMMALS
• VISUAL
• 1. POSTURAL - BASIC IN TETRAPODS
• 2. FACIAL- DEVELOPSIN MAMMALS IMPORTANTINTERRESTRI
  AL PRIMATES
  
• 3. GESTURAL (MANUAL) ONLY IMPORTANT IN HUMANS
• AUDITORY DEVELOPS IN MAMMALS (ISOLATION PEEP)