On the Evolution of Language

1. Linguistic Anthropology Onthe Evolution of Language

2. Found in all human groups • Develops along similar lines in all children • Can even develop in individuals with impairments • A product of human evolution Language is a Human Universal

3. Fossil record Archaeological record types of Paleo-evidence

4. Anatomical Bases of spoken language

5. Pharynx • Back of throat • space for tongue • Larynx • Location of vocal cords The Human Vocal Tract

6. Human infants born with high larynx • Begins to lower at three months • Reaches adult location by 3-4 years • Except in adult males: further descent at adolescence. The human vocal tract

7. The Human Vocal Tract • Lowering of the larynx • Adult humans cannot breathe and swallow at the same time • Lengthening of the pharynx • Provides more space for tongue • Enables increased vowel resonance • Differentiation of vowels: [i] [a] [u]

8. The hyoid bone a.k.a. the ”lingual bone” Does not directly articulate with other bones

9. The hyoid bone

10. The Hyoid Bone in other animals Red Howler Monkey (Alouatta seniculus)

11. The Hyoid Bone in other animals Position of hyoid bones (shaded) with tongue retracted (A) and extended (B), shown in the hairy woodpecker (Dendrocopos villosus). Northern Flicker (Colaptes auratus) The hyoid apparatus and skull of a flicker (Colaptes sp.)

12. The neanderthal hyoid bone Torso (left) and hyoid bone (above) of Neanderthal individual known as Kebara 2 ca. 60,000 B.P. (Kebara Cave, Israel)

13. Comparing the Hyoids

14. Morphology of hyoid bone is essentially modern Lack of preserved soft tissue makes it difficult to assess whether the rest of the Neanderthal vocal apparatus was like that of modern humans The short answer: we cannot yet say… Could the neanderthals speak?

15. The Human Brain • Cortex • Convoluted surface of the brain • Two millimeters thick • Surface area 1.5 square yards • Contains 100 million neurons • Oldest part of cortex • Controls long term memory • and emotion • Newer part of cortex • “Neocortex” • Controls language • 80% of human brain • Divided (by sulci) into lobes • Frontal • Temporal • Parietal • Occipital

16. Broca’s area • Clarity of speech • Function words • Some word order • Wernicke’s area • Understanding words • Producing sentences Language Areas of the Brain

17. Brain endocasts Fossilized face (left) and cranial endocast (right) of the “Taung” child(Australopithecus africanus)

18. Brain endocasts • Reveal details of the brain case, which in turn reflect some detail of the brain’s surface • Do not provide an indication of the internal structures or architecture of the brain Endocasts of several Australopithecus specimens

19. Brain endocasts • Position of lunate sulcus posterior in Australopithecus • Anterior to lunate sulcus: posterior parietal cerebral cortex • Responsible in humans for object appreciation, facial recognition, and social communication Endocast of Stw 505 (A. africanus) (Sterkfontein, South Africa) (ca. 3 mya – 2 mya)

20. Brain endocasts Above: Virtual endocast of LB1 (Homo Floresiensis) Right: LB1 (middle); mcHS (microcephalic Homo sapiens) HS (Homo sapiens); He (Homo erectus); PT (Pan troglodytes)

21. Brain endocasts • Indicate aspects of brain reorganization that may have led to the development of features now associated with language • Do not demonstrate that these features were used for language Reconstructed brain and endocast of Zhoukoudian V (Homo erectus) (ca. 400,000-500,000 ya)

22. FOXP2 (forkhead Box P2) gene Point mutation in humans results in • defects in the grammatical processing of words • difficulties understanding complex sentence structures • inability to form intelligible speech • defects in the ability to move the mouth and face not associated with speaking • significantly reduced IQ Vernes SC, Oliver PL, Spiteri E, Lockstone HE, Puliyadi R, et al. (2011) Foxp2 Regulates Gene Networks Implicated in Neurite Outgrowth in the Developing Brain. PLoS Genet 7(7) http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002145; accessed 2 Sept. 2013

23. FOXP2 (forkhead Box P2) gene • Chromosome 7 • Codes for transcription factor (protein that regulates neural development) • 715 amino acids • Difference of 2 amino acids in chimpanzee vs. human proteins • Mutation likely arose 10,000-100,000 yBP Image modified from Enard et al, 'Molecular evolution of FOXP2, a gene involved in speech and language', Nature 418, 869 - 872, (2002); found at http://www.evolutionpages.com/FOXP2_language.htm; accessed 2 September 2013.

24. Cultural evidence of language use

25. Cultural evidence - HandAXES 550 kya north-east Norfolk, England How to make a handaxe 250 to 500 kya Franschhoek, South Africa

26. Cultural evidence - art Blombos Cave - Ochre Tablet Ca. 73 kya Blombos Cave Shell Beads ca. 73 kya Acheulean figurine, Israel ca. 230 kya

27. Cultural evidence - art Hyena – Chauvet Cave, France ca. 32 kya

28. Cultural evidence - writing Harappa Ca. 5,500 B.P. Egypt Ca. 5,300 – 5,200 B.P. Left: Cuneiform text, Mesopotamia Ca. 5,100 B.P.

29. What can we say?

30. We cannot clearly determine when human language first emerged • Both anatomical and artifactual material suggests that human intelligence evolved in a series of steps • A gradual emergence? A “final” step? We do not yet know…