1 Speech and Language Dr Derakhshandeh, PhD

3 Thinking and Language Language is the ability to encode ideas into signals for communication Nothing is more human than speech

4 Language is the most complex everyday human behavior 100 muscles work at any given time for speech For each of these there are about 100 nerve endings We produce 14 sounds per second (100 x 100 x 14=140,000 nerve-to-muscle events each second of conversational speech

5 How complex? …linguistic knowledge

6 more than 6,000 languages exist it is incomprehensible to suggest: language could be viewed as some sort of simple, clear-cut addition to human physiology made possible by an enlarged brain unique to Homo sapiens

7 The central ideas of evolution The life has a history Changed over time Different species share common ancestors

8 DNA (deoxyribonucleic acid) DNA is the double-stranded molecule that contains the genetic code Jared Diamond suggests: –the amount of DNA similarity is a key indicator of the closeness to other primates, esp., the Bonobos

9 Almost us!

10 Common and pygmy chimps differ in 0.7% DNA »Gorillas differ in 2.3%

11 Humans and chimps differ in 1.6% (98.4% the same) Gorillas separated from chimps before humans did

12 DNA One of the ways we determine closeness with other primates Closest primates are: – Bonobo (pygmy) –chimpanzees –Gorilla –Orangutan

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14 the genetic distances between Hominoids Chimpanzees are actually closer to humans genetically than to Orangutans and the same genetic distance from Gorillas Orangutans are the most different from humans genetically yet relatively closer to Chimpanzees

15 Hominoids

16 A polygenetic or monogenetic linguistic origin? Monogenesis? –A single location from which all humans emerged Polygenesis? –More than one location –but similar development in each site

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18 Speech begins… When? By at least 30,000 years ago: – humans speech was fully modern Begins between Australopithecines and Homo habilus (between 4M B.P. and 700,000B.P.)

19 Were there other human species? Homo habilis About 5 foot tall average brain size 650cc, much larger than Australopithecines Brain organization may have included an area for speech (Broca's area)

20 H. habilis

21 Australopithecus afarensis 3.5 to 4 foot tall, known as "Lucy“ Pelvis and legs more like humans but skull chimp like Protruding mouth, small brained, canines project slightly

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24 One possible relationship to other hominids

25 Basic biological aspects of human language: Brain Cerebral Left hemisphere Corpus callosum Neo-Cortex Broca’s Area Wernicke’s Area Angular Gyrus

26 Comprehension of speech Controls the muscles of the lips, jaw, tongue, vocal cord,…

27 Basic biological aspects of human language: Voice Box Hyoid Bone Larynx Trachea Tongue Oral/Nasal Cavity

28 Voice Box

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32 Sound Sound is produced when air flowing from the lungs passes into the voice box through the gap made by the vocal cords, which open and close like a valve During speech, the vocal cords vibrate as air passes through them releasing a rapid series of puffs into the vocal tract determines the pitch of a person's voice the faster the rate, the higher the pitch

33 Sound systems The human upper respiratory tract made speech possible as the high larynx seen in species like the chimp dropped creating an expanded pharynx in human

34 Sound systems

35 Unfortunately: "speech does not fossilize" notes anthropologist John Shea of the State University of New York: Writing appears 6000 years ago there is scant evidence for the existence of notation before 13,000 years ago How long might LANGUAGE have been around before that?

36 Fossils: the brain capacity Is raw for complex LANGUAGE with the necessary mouth and throat anatomy were probably in place before 150,000 years ago But most of the behaviors thought to depend on LANGUAGE did not appear until 40,000 years ago tools, burials, living sites, and occasional hints of art and social organization "Everybody would accept that by 40,000 years ago, LANGUAGE is everywhere" (Stanford University archaeologist Richard Klein)

37 Delayed takeoff. The anatomy needed for speech was in place before 150,000 years ago, but the signs of complex language don't proliferate until around 40,000 years ago

38 Where/When was the first Language? What does comparative linguistics tell us? What does an analysis of human mitochondrial DNA tell us?

39 The term Proto-World language the hypothetical latest common ancestor of all the world's languages an ancient language all modern languages and language families Including all known dead languages would have been spoken roughly 200,000 years ago

40 The Origin of Language Merritt Ruhlen: Suggests that if you go systematically back and compare cognates you can eventually find a common relationship among all languages Says that mitochondrial DNA analysis suggests that it is true Critics suggest: that it is too easy to mistake words that are not cognatic as cognates

41 Proto-World language Chinese shui'water' Quechua sut'u'wet' French suée'sweat' Greek hudor 'water' Dutch schuit'boat' Turkish su 'water'

42 Proto-World language Chinesenü'woman' Quechuañusta'princess' Dutchnuf'aloof girl' Greek(gy)ne'woman' Latin (femi)na'woman' Frenchnana'woman' German-infem. suffix

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44 Blood factor Rhesus negative

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46 Are there any answers in language acquisition theory? Critical Age hypothesis: Order of language development Babbling One-word stage Two-word stage Telegraphic speech Orderly addition of grammar Orderly addition of cognitive concepts

47 A new stage in human evolution The origin of language the beginning of culture, including art, desire, and the sacred new forms of social organization which are radically different from animal language is so radically different from animal communication systems its origin must have been a singular event Since this event leaves no fossil record only hypothesize about the conditions of its origin

48 For archaeologists eager to learn how we became human when and how LANGUAGE emerged is a crucial question

49 “Speech” is a wonderful gift from God