This document reanalyzes anatomical changes that have been attributed to the evolution of language. It argues that the descent of the larynx and loss of laryngeal air sacs were not necessarily driven by speech. The descent of the larynx may have initially occurred for size exaggeration and improved breathing before language. Evidence for when laryngeal air sacs were lost is inconclusive, and their loss could have been advantageous for directional calling and breathing efficiency regardless of language. Overall, the document concludes there are no irrefutable anatomical changes that can be traced specifically to the evolution of language abilities.

1. A Reanalysis of Anatomical Changes for Language Richard Littauer University of Edinburgh richard.littauer@gmail.com @richLitt

2. Outline Anatomical evolution driven by speech

3. Outline Anatomical evolution driven by speech Descent of the larynx

4. Outline Anatomical evolution driven by speech Descent of the larynx Loss of laryngeal air sacs and the hyoid bone

5. Outline Anatomical evolution driven by speech Descent of the larynx Loss of laryngeal air sacs and the hyoid bone Other reasons

6. Outline Anatomical evolution driven by speech Descent of the larynx Loss of laryngeal air sacs and the hyoid bone Other reasons Phonological realisation in whistle languages

7. Outline Anatomical evolution driven by speech Descent of the larynx Loss of laryngeal air sacs and the hyoid bone Other reasons Phonological realisation in whistle languages Conclusion

8. Evolution of Homo sapiens 15mya – Hominidae(from gibbons)

9. Evolution of Homo sapiens 15mya – Hominidae(from gibbons) 10mya – Hominini(from gorilla)

10. Evolution of Homo sapiens 15mya – Hominidae(from gibbons) 10mya – Hominini(from gorilla) 4.6mya – Ardipithicus(arboreal)

11. Evolution of Homo sapiens 15mya – Hominidae(from gibbons) 10mya – Hominini(from gorilla) 4.6mya – Ardipithicus(arboreal) 3.3mya – Austrolopithecusafarensis (bipedal)

12. Evolution of Homo sapiens 15mya – Hominidae(from gibbons) 10mya – Hominini(from gorilla) 4.6mya – Ardipithicus(arboreal) 3.3mya – Austrolopithecusafarensis (bipedal) 1.2mya – Homo neanderthalensis

13. Evolution of Homo sapiens 15mya – Hominidae(from gibbons) 10mya – Hominini(from gorilla) 4.6mya – Ardipithicus(arboreal) 3.3mya – Austrolopithecusafarensis (bipedal) 1.2mya – Homo neanderthalensis 600kya – Homo heidelbergensis

14. Evolution of Homo sapiens 15mya – Hominidae(from gibbons) 10mya – Hominini(from gorilla) 4.6mya – Ardipithicus(arboreal) 3.3mya – Austrolopithecusafarensis (bipedal) 1.2mya – Homo neanderthalensis 600kya – Homo heidelbergensis 200kya – Homo sapiens

15. Descent of the Larynx Leibermanet al. (1969) – for speech

16. Descent of the Larynx However, Fitch (1994) argued otherwise:

17. Descent of the Larynx However, Fitch (1994) argued otherwise: Two reasons for descent of the human larynx:

18. Descent of the Larynx However, Fitch (1994) argued otherwise: Two reasons for descent of the human larynx: Early, for size exaggeration

19. Descent of the Larynx However, Fitch (1994) argued otherwise: Two reasons for descent of the human larynx: Early, for size exaggeration Later, giving 2-chamber vocal tract

20. Descent of the Larynx However, Fitch (1994) argued otherwise: Two reasons for descent of the human larynx: Early, for size exaggeration Later, giving 2-chamber vocal tract “Improved speech is no longer the only plausible evolutionary explanation for laryngeal descent, as previously assumed (Lieberman 1984), and it is possible that the descended larynx in adults evolved before spoken language.” Fitch (2009, 293)

21. Descent of the Larynx What does this mean?

22. Descent of the Larynx What does this mean? That the evolutionary timeline is loose.

23. Descent of the Larynx What does this mean? That the evolutionary timeline is loose. Case and point; the hyoid bone.

24. Descent of the Larynx What does this mean? That the evolutionary timeline is loose. Case and point; the hyoid bone. Specimens from A. afarensisand H. heidelbergensis

25. Laryngeal Air Sacs Air sacs are cavities that are attached to the vocal apparatus. They are present in many mammals (Frey et al., 2007).

26. Laryngeal Air Sacs Air sacs are cavities that are attached to the vocal apparatus. They are present in many mammals (Frey et al., 2007). Only lateral ventricle air sacs occur in the ape line (Hewitt et al., 2002).

27. Laryngeal Air Sacs Air sacs are cavities that are attached to the vocal apparatus. They are present in many mammals (Frey et al., 2007). Only lateral ventricle air sacs occur in the ape line (Hewitt et al., 2002). Homo sapiens no longer have air sacs, except in rare pathological cases and in certain specific circumstances involving irregular behavior-caused modification of the vocal tract.

28. Laryngeal Air Sacs

29. Laryngeal Air Sacs Justifications for loss:

30. Laryngeal Air Sacs Justifications for loss: ‘Airsacculitis’: infection of the air sac.

31. Laryngeal Air Sacs Justifications for loss: ‘Airsacculitis’: infection of the air sac. The ability to modify breathing patterns

32. Laryngeal Air Sacs Justifications for loss: ‘Airsacculitis’: infection of the air sac. The ability to modify breathing patterns Reduction of the need for a device that would prevent hyperventilating (Hewitt et al., 2002)

33. Laryngeal Air Sacs Justifications for loss: ‘Airsacculitis’: infection of the air sac. The ability to modify breathing patterns Reduction of the need for a device that would prevent hyperventilating (Hewitt et al., 2002) Disadvantageous for subtle, timed, and distinct sounds, which are necessary for human speech. (de Boer 2010)

34. Laryngeal Air Sacs Two arguments for recent loss (less than 600kya):

35. Laryngeal Air Sacs Two arguments for recent loss (less than 600kya): Anatomical herniation

36. Laryngeal Air Sacs Two arguments for recent loss (less than 600kya): Anatomical herniation Size/Loss correlation

37. Laryngeal Air Sacs Anatomical evidence for the hyoid bone and the bulla as the sole indicators of air sacs is poor.

38. Laryngeal Air Sacs Anatomical evidence for the hyoid bone and the bulla as the sole indicators of air sacs is poor. Laryngeal air sacs can regularly project between, reposition, and herniate muscles in the larynx (Giovannielloet al., 1970)

39. Laryngeal Air Sacs Anatomical evidence for the hyoid bone and the bulla as the sole indicators of air sacs is poor. Laryngeal air sacs can regularly project between, reposition, and herniate muscles in the larynx (Giovannielloet al., 1970) In primates, “A maximum of four types of [laryngeal] air sac (lateral ventricular, subhyoid, infraglottal and dorsal) have been identified, but no single source describes the morphology and summarises the distribution of all the types of air sac.” (Hewitt et al., 2002; 71)

40. Laryngeal Air Sacs Anatomical evidence for the hyoid bone and the bulla as the sole indicators of air sacs is poor. Laryngeal air sacs can regularly project between, reposition, and herniate muscles in the larynx (Giovannielloet al., 1970) In primates, “A maximum of four types of [laryngeal] air sac (lateral ventricular, subhyoid, infraglottal and dorsal) have been identified, but no single source describes the morphology and summarises the distribution of all the types of air sac.” (Hewitt et al., 2002; 71) Laryngocoeles can occur due to excessive build up in pressure in the glottis, which stretches the internal wall to form a sac.

41. Laryngeal Air Sacs In 75% of studies involving air sac loss in primates, they were lost coincidentally with size reduction. (Hewitt et al. 2002)

42. Laryngeal Air Sacs In 75% of studies involving air sac loss in primates, they were lost coincidentally with size reduction. (Hewitt et al. 2002) This was a synchronic study, and so Homo sapiens was considered an exception

43. Laryngeal Air Sacs In 75% of studies involving air sac loss in primates, they were lost coincidentally with size reduction. (Hewitt et al. 2002) This was a synchronic study, and so Homo sapiens was considered an exception But – Homo heidelbergensiswas taller and more robust than Homo sapiens. (Churchhillet al. 2000)

44. Laryngeal Air Sacs Two justifications for loss itself:

45. Laryngeal Air Sacs Two justifications for loss itself: Call directionality

46. Laryngeal Air Sacs Two justifications for loss itself: Call directionality Regular breathing

47. Laryngeal Air Sacs Call directionality:

48. Laryngeal Air Sacs Call directionality: The linguistic niche of hunting in the environment in which early hominin hunters (1.2mya) have been posited to exist is the savannah.

49. Laryngeal Air Sacs Call directionality: The linguistic niche of hunting in the environment in which early hominin hunters (1.2mya) have been posited to exist is the savannah. This would have been better suited to higher frequency, directional calls as opposed to lower frequency, multidirectional calls.

50. Laryngeal Air Sacs Call directionality: The loss of air sacs would have then been directly advantageous, as lower frequencies produced by air sac vocalisations over bare ground have been shown to favor multidirectional over targeted utterances (Frey and Gebler, 2003; 469).

51. Laryngeal Air Sacs Regulated Breathing:

52. Laryngeal Air Sacs Regulated Breathing: Laryngeal ventricular air sacs, as seen in apes, open into the vocal tract above the vocal folds.

53. Laryngeal Air Sacs Regulated Breathing: Laryngeal ventricular air sacs, as seen in apes, open into the vocal tract above the vocal folds. This means that, as air is passed into the lungs, air is drawn from the sac, and as it is exhaled, the sac fills with air.

54. Laryngeal Air Sacs Regulated Breathing: Laryngeal ventricular air sacs, as seen in apes, open into the vocal tract above the vocal folds. This means that, as air is passed into the lungs, air is drawn from the sac, and as it is exhaled, the sac fills with air. The air sac would serve as a sink of already-used air that would continually be reused while breathing, an inefficient mechanism that would be disadvantageous in cases of sustained oxygen depletion.

55. Laryngeal Air Sacs The point being?

56. Laryngeal Air Sacs The point being? There are paralinguistic reasons for loss of air sacs, as well. Claims otherwise are speculative.

57. Other Anatomical Changes Other anatomical changes for speech:

58. Other Anatomical Changes Other anatomical changes for speech: Hypoglossal canal

59. Other Anatomical Changes Other anatomical changes for speech: Hypoglossal canal (debunked: DeGustaet al. 1999)

60. Other Anatomical Changes Other anatomical changes for speech: Hypoglossal canal (debunked: DeGustaet al. 1999) Voluntary breathing control

61. Other Anatomical Changes Other anatomical changes for speech: Hypoglossal canal (debunked: DeGustaet al. 1999) Voluntary breathing control (1.2–100kya: McLarnon and Hewitt 1999)

62. Other Anatomical Changes Other anatomical changes for speech: Hypoglossal canal (debunked: DeGustaet al. 1999) Voluntary breathing control (1.2–100kya: McLarnon and Hewitt 1999) Specialisedhearing

63. Other Anatomical Changes Other anatomical changes for speech: Hypoglossal canal (debunked: DeGustaet al. 1999) Voluntary breathing control (1.2–100kya: McLarnon and Hewitt 1999) Specialised hearing (Related to what you produce: Hauser and Anderson 1994)

64. Other Anatomical Changes Other anatomical changes for speech: Hypoglossal canal (debunked: DeGustaet al. 1999) Voluntary breathing control (1.2–100kya: McLarnon and Hewitt 1999) Specialised hearing (Related to what you produce: Hauser and Anderson 1994) Mirror neurons

65. Other Anatomical Changes Other anatomical changes for speech: Hypoglossal canal (debunked: DeGustaet al. 1999) Voluntary breathing control (1.2–100kya: McLarnon and Hewitt 1999) Specialised hearing (Related to what you produce: Hauser and Anderson 1994) Mirror neurons (As far back as Pan)

66. Other Anatomical Changes Other anatomical changes for speech: Hypoglossal canal (debunked: DeGustaet al. 1999) Voluntary breathing control (1.2–100kya: McLarnon and Hewitt 1999) Specialised hearing (Related to what you produce: Hauser and Anderson 1994) Mirror neurons (As far back as Pan) FOX2P

67. Other Anatomical Changes Other anatomical changes for speech: Hypoglossal canal (debunked: DeGustaet al. 1999) Voluntary breathing control (1.2–100kya: McLarnon and Hewitt 1999) Specialised hearing (Related to what you produce: Hauser and Anderson 1994) Mirror neurons (As far back as Pan) FOX2P (In mice and orangutans.)

68. Other Anatomical Changes So, what remains?

69. Other Anatomical Changes So, what remains? The conclusion that there are no major specific anatomical changes that can be traced irrefutably to language.

70. Phonological Implications Current theoretical studies on the evolution of sounds depend almost entirely on complex phonemic inventories

71. Phonological Implications Current theoretical studies on the evolution of sounds depend almost entirely on complex phonemic inventories These do not exist a priori, but rather appear through cultural evolutionary processes

72. Phonological Implications Current theoretical studies on the evolution of sounds depend almost entirely on complex phonemic inventories These do not exist a priori, but rather appear through cultural evolutionary processes Self-organisation

73. Phonological Implications Current theoretical studies on the evolution of sounds depend almost entirely on complex phonemic inventories These do not exist a priori, but rather appear through cultural evolutionary processes Self-organisation Phenomena of the third kind (Invisible hand)

74. Phonological Implications Most current theoretical studies on the evolution of sounds depend almost entirely on complex phonemic inventories These do not exist a priori, but rather appear through cultural evolutionary processes Self-organisation Phenomena of the third kind (Invisible hand) With bounded constraints (production, perception)

75. Phonological Implications However, they take it for a given that these sounds shaped anatomy, rather than are artefacts of it.

76. Phonological Implications However, they take it for a given that these sounds shaped anatomy, rather than are artefacts of it. “The investigation of the interaction between vocal fold interactions and vocal tracts with air sacs presented here, although preliminary and incomplete, supports the hypothesis that the evolutionary disappearance of air sacs is related to the emergence of complex vocal communication.” (de Boer, 2010)

77. Phonological Implications If complex phonemic inventories did not shape their anatomical mechanisms of production (as I’ve suggested), then other modes of communication may be equally weighted in protolanguage theories

78. Phonological Implications If complex phonemic inventories did not shape their anatomical mechanisms of production (as I’ve suggested), then other modes of communication may be equally weighted in protolanguage theories These would include:

79. Phonological Implications If complex phonemic inventories did not shape their anatomical mechanisms of production (as I’ve suggested), then other modes of communication may be equally weighted in protolanguage theories These would include: Whistled/hummed language

80. Phonological Implications If complex phonemic inventories did not shape their anatomical mechanisms of production (as I’ve suggested), then other modes of communication may be equally weighted in protolanguage theories These would include: Whistled/hummed language Gesture and signed language

81. Phonological Implications If complex phonemic inventories did not shape their anatomical mechanisms of production (as I’ve suggested), then other modes of communication may be equally weighted in protolanguage theories These would include: Whistled/hummed language Gesture and signed language Non-arbitrary phonemic language

82. Phonological Implications Whistled languages:

83. Phonological Implications Whistled languages: Copy the tone, formants, intonation of regular language

84. Phonological Implications Whistled languages: (Meyer 2008) Copy the tone, formants, intonation of regular language Are more common and more unimodal in tonal languages

85. Phonological Implications Whistled languages: (Meyer 2008) Copy the tone, formants, intonation of regular language Are more common and more unimodal in tonal languages Suitable for different environments (as clicks are (Knight et al. 2003)

86. Phonological Implications Whistled languages: (Meyer 2008) Copy the tone, formants, intonation of regular language Are more common and more unimodal in tonal languages Suitable for different environments (as clicks are (Knight et al. 2003) Interchangeable with regular language

87. Phonological Implications Non-arbitrariness in language: (Cuskley 2008)

88. Phonological Implications Non-arbitrariness in language: (Cuskley 2008) Iconicity

89. Phonological Implications Non-arbitrariness in language: (Cuskley 2008) Iconicity Phonesthemes

90. Phonological Implications Non-arbitrariness in language: (Cuskley 2008) Iconicity Phonesthemes Infant directed speech

91. Phonological Implications Non-arbitrariness in language: (Cuskley 2008) Ideophones (Voeltz & Killian-Hatz, 2001) Phonesthemes (Bergen, 2001) Infant directed speech (Nygaard et al, 2009) Statistical correspondences (Tamariz, 2005)

92. Conclusion To sum up:

93. Conclusion To sum up: The major reasons cited for the evolution of speech mechanisms are somewhat unsubstantiated

94. Conclusion To sum up: The major reasons cited for the evolution of speech mechanisms are somewhat unsubstantiated This results in a re-appraisal of language evolution to a more recent time period – or suggests that different language-internal pressures were present in protolanguage

95. Conclusion To sum up: Multimodality is an integral part of otherwise solely-phonological speech

96. Conclusion To sum up: Multimodality is an integral part of otherwise solely-phonological speech Given this, reducing justifications for anatomical change to phonemic systems is unjustified, and a reanalysis of evolutionary phonology is warranted.

97. Conclusion Thank you. References available upon request.