How did human language evolve?

1. How did human language evolve? Presentation for ANP 840

3. Language Evolution: Basic Questions • What is the difference between language origins and language evolution? • Why do you want to study the origin and evolution of language? • What is the relationship between language/communication and human physiology? • What is the relationship between language and being human? • Answers at the end of the lecture.

4. Evolution of Language versus Origin of Language. • What’s the difference? • Very little done these days on the evolution of language and the evolution of culture. • Why?

5. Early Approaches • The study of evolution of humanity has been approached from: • The evolution of the human body (physical anthropology) • The evolution of culture (sociocultural anthropology) • The evolution of language (linguistics) • Traditionally, each domain each has been studied independently of each other without the awareness that the areas are dialectically interdependent. • Early assumptions based on concepts of • Absolute progress, • Linear development • Eurocentricity • The failure to recognize the interconnectedness of the three areas.

6. The Autonomous Study of The Evolution of Culture • The domain of the cultural anthropologists (Tylor, Morgan, ….) • e.g., savages, barbarians, civilization • Early models • Did not relate to evolution of the body or to language or to culture other than to say a bigger brain implied greater intelligence. • Based on the assumption that Europe represented the most advanced form of cultural evolution. That some societies represented “living fossils”. • Presumed the ability to sign was unique to humans. • Leslie White

7. The Autonomous Study of the Evolution of the Human Body • The domain of the physical anthropologists. • Studies of Brain Development • Bigger brain – smarter animal and capacity for culture. • Unaware of the modular hypothesis, bigger brain – smarter creature. • What is the modular hypothesis? • The development of bipedalism. • Such approaches (2 & 3) did not help us understand our uniqueness of humans.

8. Who Are Our Ancestors? • Australopithecus Afarensis: -4 -3 million • Homo Habilis: -3 to -1 million • Homo Erectus: -1 Million to -200,000 • Homo Sapiens: • Archaic • Neanderthalensis: 300,000 – 50,000 BP • Sapien: 50,000 - Present

9. Brain Size * Evidence of Broca’s and Wernicke’s in HH

10. The Autonomous Study of The Evolution of Language • Early views: Much like the early culture models, primitive languages as living fossils. • Early invention stories. (Yo-heave ho, bow-wow, click-clack) • Psammethicus: Egyptian King (664-610 BC) • Hockett’s linear evolution model • Increasing complexity of message systems • Hill and other’s discontinuity • The ability to speak different from intelligence. • Comparative Primate Studies • Evolution of Language Structure • (surprisingly very few have looked at this)

11. Questions of learning and intelligence • Continuity: Hockett • Focused on the evolution of communication, • Proposed a number of design features found in communication. • Charted their evolutionary sequence. • Communicative competency seen as a function of intelligence/brain size. • Discontinuity, Hill, Chomsky, Lenneberg, Piaget • Language ability is independent of general intelligence. • Adaptive value of language • Comparison of Argentine birds with early humans. (creation of learnable dialects in certain types of birds (passerine) produces smaller breading populations which means a greater potential to adapt to smaller ecological niches.

12. Hockett’s Design Features

13. Comparative Primate Studies • Chimpanzee Studies • Washoe (Gardener and Gardner) • Nim Chimsky (Herbert Terrace) • Others (Yerkees, …) • Monkey Studies • Sefarth on Signing

14. Comparative Primate Studies

15. The motor areas of a monkey and human brain.

16. Comparative Brain Development

17. Chimpanzee Language Studies • Could use the representational signing system of American Sign Language. • Showed the capacity for controlling signs. • Arbitrary association of signifier and signified • Able to prevaricate • Question of face? • Showed ability to create atactic and paratactic sentences.

18. Sefarth’s Studies of Signing Potentials • Basic question, what are the properties of the sign and what are the associated mental abilities use them. • Which of these capacities do our phylogenetic relatives possess?

19. 1. Association of Signifier and Signified 1 Examples of different signs used by monkeys 2. Note range of signifiers.

20. .What does it mean to use a word? Seyfarth identified several abilities an organism must possess in order to use a word. As some of his terminology conflicted with existing linguistic usage, I chose to redefine them without losing the sense.

21. Chimpanzees and Tactic AbilitiesParataxis versus Syntax • Two word Sentences: Parataxis • Case like relationships • Three word sentences • Mean length of utterance • Syntactic signs – the basis for syntax

22. Comparison of Chimp and Human Case-like relationships

24. Analysis of three word sentences Three-word combinations e.g. “Play me. Nim.” could be viewed • as either incipient syntax or • a sequence of a paratactic and atactic sentence. • Play me. + Nim. • Here the second sentence, “Nim.” is seen as emphasizing, or clarifying, the me or the first sentence. But the incipient syntax hypothesis offers no insights.

28. Syntactic Signs and Parts of Speech

29. The Perils of Parataxis The Far Side By Gary Larson

30. Integrated Approaches • New understandings have emerged once we start looking at integrated models. • Once we discover the interactions between the two • The principle of dialectics or coevolution • Body and Culture • Body and Language • Language and Culture

31. Body and Culture • Body Culture • Tools • Other physical manifestations of human culture. • Questions of the interrelatedness of body and culture

32. Australopithecus Afarensis Technology: No tools identified. Architecture: ?? Art and Letters: ?? Religion: ?? Biology: Brain: 375-500 ml. Upright posture.

33. Homo Habilis: -3 to -1 million Tech: Stone tools (Oldowan), Definite Omnivore Habitat: Savannah Habitat. Arts: Religion: Biology: Brain: 500-800 ml. Evidence of buldge in Broca's area. Homo Erectus: -1 Million to -200,000 Tech: Better made Tool Kit (Acheulean), Fire, Definite Omnivore. Habitat: Moved out of Africa; Varried habitat. Arts: ?? Religion: ?? Biology: Brain: 750-1250 ml. Some evidence of vocal tract development

34. Homo Sapiens Neanderthalensis 300,000 to -50,000 BP Tech: Uniform tools (secondary chipping) Levallois spread rapidly at expense of Erectus. Habitat: Clothing, tent pegs? Arts: Care of aged. Religion: Burial of dead with implements. Some use of red ochre). Biology: Brain: 1100 -1300 ml. (same as HSS)

35. 50,000 Years B.P. Vocal tract in place; brain has modern volume; Stronger evidence of Broca's area; appearance of Homo Sapiens. 37,000 to 22,000 BP Aurignatian Tech: Advanced Hunting techniques, thin blades, chisels, gravers, tools for bone working. Habitat: Iran and Afganistan Arts: Simple animal cave drawings (some areas). Religion: Burial of dead with red ochre. Biology: Modern Man (cromagnon)

36. The Integrated Study of the Body and Language • Language Body • The evolution of the brain • The modular hypothesis and the language processing areas of the brain. • The evolution of the vocal tract • How the (2 tube) vocal tract evolved to produce a more efficient transmitter of information. • Chomsky – the syntax gene. • Was there a genetic change that enabled humans to speak syntactically?

37. Body Questions: The Brain • What is the modular principle? • Why is it relevant to the study of language? • What are the modules relevant to the study of language? • When did they develop?

38. When did Broca's area develop? Endocranial casting of fossil sculls suggests that Broca's area has been evolving for at least 100,000 years. Other Evidence suggests Homo Habilis • When did the Wernicke's Area develop? Also Homo Habilis • When did The Arcuate Fasciculus (nerves connecting Broca's and Wernicke's area. We have concluded that there are significant differences, evident in the fossil record, that distinguish H. habilis from the australopithecines with respect to neurolinguistic preconditions. These include a demarcated Broca's area, an identifiable POT (indicative of Wernicke's area), and asymmetrical development of the cerebral hemispheres indicative of handedness. Wilkins, W.K. & Wakefield, J. (1995). Brain evolution and neurolinguistic preconditions. Behavioral and Brain Sciences 18 (1): 161-226

39. Caveat • Examination of endocasts of fossil hominids has suggested to some researchers that the neurological substrate for the production of language was in place as early as 2 million years ago. Enlarged perisylvian structures (like Broca's and Wernicke's areas), along with increasing cerebral asymmetry (another indication of specialized brain function) act as evidence for the early development of language centers. However, difficulties arise in the interpretation of fossil endocast materials, particularly the accuracy of endocrania, endocasts, and the validity of assuming any kind of continuous function from present to past. Other researchers contend that the emergence of language did not occur until after 100,000 years ago, when the production of the full compliment of human-like sounds was not hindered by the morphology of the throat

40. The evolution of the Vocal Tract • Some evidence of vocal development in Homo Habilis (1-3 million). • The two tube vocal tract fully developed by 50,000 BP • Why did humans shift to a completely vocal representational system. • What activities, events would encourage the vocal tract. • Upright posture?

41. The Production and Recognition of Vowels • Underlying the human vocal system is the dialectical relationship between the production and recognition of vowels. • The recognition of vowels depends on the identification of the first and the second formant. • The production of formants in the vocal tract can be understood as an illustration of the source-filter theory. • What is the source? What is the filter?

42. The recognition of vowels The above picture is a sound spectogram which maps frequency vertically and time horizontally.

43. The Vocal Tract as an acoustic filter The filters include the oral cavity, the pharynx and the nasal cavity. The oral cavity and pharynx are coupled producing a filter 17 cm in length. The source is the voice box or larynx.

44. An Example • Wave lengths • Speed of sound = 33,500 cm per second. • Frequency: number of cycles (highs and lows per second) • Unit = Hertz (Hz). • Wave length = How far a sound at a frequency can travel. • A 1 Hz wave can travel 33,500 cm A 100 Hz wave can travel 335 cm • A 2 Hz wave can travel 16,750 cm A 500 Hz wave can travel 67 cm • A 10 Hz wave can travel 3,350 cm • What’s so great about 67 cm? • 67 is 4 times 17. (16.75) • Whats so great about 17? • Length of human vocal tract.

45. What is the relationship between 17 and 64 • The filter is a simple question of fitting a wave in a tube. • A formant is the frequency of wave that is reinforced by the filter. • Length is the primary consideration • Open, half open and closed tubes function differently. • A full wave fits in a closed tube. • A half a wave fits in a half-closed tube. • A quarter wave fits in an open tube.

46. The significance of the numbers 500 and 17 • The first formant of an open tube 17 cm long is 500 Hertz • 500 Hertz is the first formant of the vowel schwa. • Thus source-filter theory demonstrates that the first formant of the vowel schwa is the simple consequence, a 17 cm long straight tube acting as a filter.

47. Schematic of the vowels a i u

48. Formant 1 versus Formant 2

49. The production of vowelsThe Source-Filter Theory (Acoustics) • The Source of sound to be filtered • Noise = sound at all frequencies • The voice box (a.k.a. larynx • The Filter • Formants are frequencies are those reinforced by the filter. • Non-formants are those not reinforced by the filter. • Formants are primarily dependent on the length of the filter.

50. The reason for a 2 tube vocal tract. • The source-filter theory • The production of vowels • The production of consonants • Why the 2 tube vocal tract works.