Language

Question 1

What are the 3 key hypotheses presented in lectures regarding the emergence of language?
Give a brief description of each

Answer 1

Why Only Us hypothesis (Berwick & Chomsky, 2016): language restricted to Homo sapiens and emerged in the last 300 000 years.

• Gradual hypothesis: language emerged within Homo with Mode 2 technology around 1.75 Ma.
• ‘The Much Older hypothesis’: before 1.75 Ma?

Question 2

What are the 3 key areas that can be explored in the fossil record which can be used to examine the emergence of language in detail

Answer 2

auditory capacity

cognition

vocal tract

Question 3

What do you call brain mapping

Answer 3

Brain parcellation

Question 4

What are cortical areas

Answer 4

Cortical areas: regions defined by their microstructural architecture, functional specialization, connectivity or topographic organization (Brodmann’s areas, BA).

Question 5

What are the key parts of the brain associated with language?

Where are they located ?

Answer 5

Broca’s cap: located in the inferior frontal gyrus and formed by BA 44 (pars opercularis) and BA 45 (pars triangularis).

• Wernicke’s area: located in the posterior part of the superior temporal gyrus, and part of BA 22.
• Both located in the dominant cerebral hemisphere for language (right/left, left in 95% of living humans).

Question 6

What are the structural and shape characteristics of the Broca’s cap and the Wernicke’s area?

Answer 6

Broca’s cap: ascending and horizontal branches of the lateral fissure delineate BA 44 and 45.

Wernicke’s area: proximity of the lateral end of the lateral fissure.

Asymmetries: the Broca’s cap and the Wernicke’s area (represented by the planum temporale) are larger in the dominant hemisphere for language.

Question 7

Can we see symmetries in Broca’s areas in non-human animals?

Answer 7

Asymmetries of the Broca’s cap and planum temporale in other great apes.

BUT a different organization of the Broca’s cap in other great apes (fronto-orbital sulcus).

Question 8

What is the organization of Broca’s cap in sediba

Answer 8

Australopithecus sediba (2.0 Ma) - chimpanzee-like pattern (fronto-orbital sulcus (Carlson et al., 2011))

Question 9

Do early Homo show human-like pattern

Answer 9

Homo rudolfensis
(2.1-1.8 Ma) - two branches (Falk, 1983)

Homo habilis - (2.6-1.7 Ma) - fronto-orbital sulcus (Falk, 1983)

Question 10

What are the language centres like in later Homo brains

Answer 10

Neandertals
(0.197-0.039 Ma)
two branches
(Bruner et al., 2008)

Homo naledi
(0.3-0.2 Ma)
two branches
(Holloway et al., 2018)

Question 11

Describe the pattern of asymmetries in hominin evolution

Answer 11

Gradual increase in the degree of expression of asymmetries of the Broca’s cap:
same pattern as in extant humans and great apes but different magnitude!

Question 12

Why is Wernicke’s area hard to track in human evolution?

What can we tell?

Answer 12

Temporo-parietal region poorly represented in the fossil record.

• Strong development of the inferior parietal lobule (including Wernicke’s area)
in Homo habilis? (Tobias, 1987)

Question 13

Summarise the evidence for language from the endocast in australopithecines, early Homo, and later Homo

Answer 13

Australopithecus:
primitive Broca’s cap
some asymmetry of Broca’s cap
N/A regarding Wernicke’s area

early Homo: Broca’s cap organisation is a mix of primitive and derived
increased asymmetry of Broca’s cap
Wernicke’s area appears to be more derived (as seen in habilis skull)

later Homo:
derived Broca’s cap
pronounced asymmetry
little information on Wernicke’s area

Question 14

What is an audiogram

What does a modern human audiogram look like

Why is this important

Answer 14

Audible thresholds for specific frequencies.

• Modern human audiogram: lowered high-frequency cutoff and high sensitivity
in the low to mid-frequencies as compared to other primates

Hearing variability partly related to forms of vocalization

Question 15

What is interesting about earlier hominin ossicles

Why is this important

Answer 15

Australopithecus africanus and Paranthropus robustus ossicles: a derived malleus with primitive incus and stapes.

Primitive incus: decrease in auditory sensitivity shared with the other primates
except humans.

Question 16

Describe Neanderthal ossicles

What does this suggest

Answer 16

same functional parameters of the ossicles than in anatomically modern humans but different morphology.

• Similar auditory sensitivity, same hearing capacities, same vocal communication?

Question 17

What was the bandwidth like in later Homo

Answer 17

Broad bandwith in Homo heidelbergensis and modern humans with similar means

Question 18

What is interesting about Paranthropus’ inner ear

Answer 18

increase in the oval window area and specific cochlear shape.

• Functional adaptations for hearing sensitivity?

Very different to Homo - May need to distinguish between Paranthropines and humans

Question 19

Describe the Oval window and cochlea in Homo erectus and modern Homo

What does this suggest

Answer 19

large cochlea and oval window,

increased low frequency sensitivity emerged less than 2 Ma

Longer-range communication?

Question 20

What can cochlear length be used to estimate

Answer 20

a good estimate of low-frequency sensitivity

Question 21

How do Premodern (Homo erectus) and modern human cochleae differ from australopiths and catarrhines

why is this special

Answer 21

cochlear relative lengths and oval window areas
larger than expected for their body mass, two features corresponding to increased low-frequency sensitivity

uniqueness of the “hypertrophied” cochlea in the genus Homo (quotation from

Question 22

How does the Cochlea in Homo heidelbergensis compare to modern humans

What does this suggest functionally

Answer 22

small cochlear volume.

• Higher upper limit of hearing compared to modern humans (lower high frequency cutoff)?

Martinez et al., 2019

Question 23

What did Conde-Valverde et al., 2021 find in relation to the Neanderthal inner ear? What is the functional significance of this?

Answer 23

results show that the occupied bandwidth of Neanderthals was greater than the Sima de los Huesos hominins and similar to extant humans, implying that Neanderthals evolved the auditory capacities to support a vocal communication system as efficient as modern human speech

Question 24

Give a review of the auditory capacities of fossil hominins

Address middle and inner ear and how this will impact auditory capacity

Answer 24

early hominins:
primitive middle ear
specific inner ear to different species
capacity is primitive with some specificities

early Homo:
middle ear generally unclear
inner ear: derived
capacity: emergence of the lowered high-frequency cutoff

later Homo:
middle ear - derived
inner ear - derived
capacity - same vocal communication?

Question 25

What does the vocal tract consist of

What is its structure in extant humans

Answer 25

supralaryngeal vocal tract composed of the oral cavity (OC) and the pharynx (P).

OC and P should be the same lenght for producing some vowels: short OC and
low position of the P in extant humans

Question 26

How can we reconstruct the pharynx from fossils

Answer 26

Proxy for reconstructing P in fossil hominins: flexion of the cranial base, neck length, position of the hyoid bone.

Question 27

What has been suggested about the vocal tract in Neanderthals

Answer 27

Human-like proportions of the neck and position of the hyoid bone.

• Basicranial flexion? (Lieberman, 2012)

Question 28

What does the hyoid bone suggest about speech in afarensis

Answer 28

Australopithecus afarensis: chimpanzee-like bulla (middle of hyoid) (presence of laryngeal air sacs attached to the vocal apparatus?).

Presence of laryngeal air sac which would prevent language/ speech like ours

Question 29

What do Homo hyoid bones suggest about speech capabilities in Homo

Answer 29

Homo heidelbergensis and Neandertals: same shape and size as in modern
humans (characteristics involved in speak presence emerged at least 500, 000
years ago?)

Question 30

Summarise the evidence of speech from the reconstruction of the vocal tract from hominin fossils

Answer 30

structure of vocal tract unknown in australopithecus and early homo but derived in later homo

hyoid is primitive in australopiths, unclear in early homo, and derived in later Homo

Question 31

How can we use molecular data to assess speech capabilities of hominins

Answer 31

FOXP2 gene related to language: evolutionary changes shared by Neandertals
and extant humans (Krause et al., 2007).

Also have to be aware FOXP2 is present in a range of non-human species including mice

Question 32

How can stone tool tech be used to support emergence of language

Answer 32

Morgan (2015) tested the efficacy of transmission of Oldowan tool-making skills along chains of adult human participants (n= 184) using five different transmission mechanisms.

They found transmission improves with teaching, and particularly with language, but not with imitation or emulation

They concluded:
(i) low-fidelity social transmission, such as imitation/emulation, may have contributed to the B700,000 year stasis of the Oldowan technocomplex, and (ii) teaching or proto-language may have been pre-requisites for the appearance of Acheulean technology

This work supports a gradual evolution of language,
with simple symbolic communication preceding behavioural modernity by hundreds of thousands of years

Question 33

What did (Martínez et al., 2013) find with regards to bandwidth in Homo heidelbergensis from Atapuerca

Answer 33

Atapuerca SH hominins were similar to modern humans in this aspect, falling within the lower half of the range of variation, and clearly distinct from chimpanzees

The presence of a complete cervical segment of the spinal column associated with Cranium 5 from the Sima de los Huesos Middle Pleistocene site (Sierra de Atapuerca, Spain) makes it possible to estimate the vocal tract proportions in H. heidelbergensis - found to be similar to the reconstructed vocal tract in the La Ferrassie 1 Neandertal individual, which has been suggested to have been capable of producing the full range of sounds emitted during modern human spoken language. These results in the Atapuerca (SH) hominins are consistent with other recent suggestions for an ancient origin for human speech capacity.

Question 34

Give examples of scholars who believed language is too amazing to have evolved

Answer 34

Alfred Russel Wallace invoked divine intervention

Chomsky declared give the complexity of language that it could not possibky have evolved via natural selection

Question 35

Summarise Ramachandran’s theory for the evolution of language

Answer 35

the representation of certain lip and tongue movements in motor brain maps may be mapped in non-arbitrary ways onto certain sound inflections and phonemic representations in auditory regions and the latter in turn may have non-arbitrary links to an external object’s visual appearance

The stage is then set for a sort of ‘resonance’ or bootstrapping in the co-evolution of these factors, thereby making the origin of proto-language seem much less mysterious than people have assumed

lip and tongue movements and other vocalizations may be
synaesthetically linked to objects and events they refer to in closer ways than we usually assume and this may have been especially true early in the evolution of the proto-language of ancestral hominids

an important factor may be synaesthesia caused by cross-activation between two motor maps rather than between two sensory maps

Question 36

When did Darwin note synkinaesia

How did Ramachandran link this to the evolution of proto-language

Answer 36

Darwin (1872) noted that when cutting something with a pair of scissors we often
unconsciously clench and unclench our jaws, as if to sympathetically mimic the
hand movements

could perhaps be synkinaesia between the motor maps for the mouth and hand, which are right next to each other in the Penfield motor homunculus of the pre-central gyrus

when pointing I use my index finger to point outward to you. I also produce a partial outward pout with my lips (as in English ‘you’, French ‘tu’ or ‘vous’ and Tamil ‘thoo’), whereas when I point inward to myself, my lips and tongue move inwards (as in English ‘me’, French ‘moi’ and Tamil ‘naan’) In this manner a primitive vocabulary of gesture and pantomime could evolve through
synkinaesia into a corresponding vocabulary of tongue/palate/lip movements (causing vocalizations, especially if accompanied by guttural utterances).

Question 37

What is the key take away from Ramachandran’s theory of evolution of proto-language

Answer 37

each of these different effects (synaesthesia between object appearance and sound contour, between sound contour and vocalizations, and synkinaesia) in isolation may have been too small to have exerted adequate selection pressure for the emergence of proto-language, but a bootstrapping between all of them acting together may have indeed been sufficient

Question 38

Give an example of non-human primates can learn language

Answer 38

Washoe was a female common chimpanzee who was the first non-human to learn to communicate using American Sign Language (ASL) as part of an animal research experiment on animal language acquisition

However, subsequent experiments to perform similar results with other chimps have failed - suggesting it may have been a ‘Clever Hans’ effect

Question 39

Give an example of Washoe understanding ASL using quotes

Answer 39

Washoe: “You, Me out go”.

Human: ‘OK but first clothes’

(Washoe puts on jacket.)

Question 40

Give an example of Washoe understanding language and human emotion

Answer 40

People who should be there for her and aren’t are often given the cold shoulder—her way of informing them that she’s miffed at them. Washoe greeted Kat [the caretaker] in just this way when she finally returned to work with the chimps. Kat made her apologies to Washoe, then decided to tell her the truth, signing “MY BABY DIED”. Washoe stared at her, then looked down. She finally peered into Kat’s eyes again and carefully signed “CRY”, touching her cheek and drawing her finger down the path a tear would make on a human (Chimpanzees don’t shed tears). Kat later remarked that one sign told her more about Washoe and her mental capabilities than all her longer, grammatically perfect sentences

Question 41

Give quote about biology and evolution

Answer 41

As Dobzhansky (1973) put it, “Nothing in biology makes sense except in the light of evolution.”

Question 42

How does the outer/middle ear in Neanderthals and Australopiths compare to humans

Answer 42

• no statisti-cally significant differences between the Neanderthal (from 130kya, Krapina sample) and modern human means in any of the anatomical variables based on estimates of middle and outer ear such as concha, middle ear cavity, and ear canal

o not similar in the early hominin taxa Australopithecus africanus and Paranthropus robustus from South Africa
showed that the OBW in the early hominins was quite similar to Pan troglodyte

Question 43

Describe the cochlear of H. hiedelbergensis

What about Australopiths

Answer 43

 SH hominins differ from modern humans in two aspects of their hearing pattern: a slightly narrower band of maximum sensitivity in the midrange frequencies (1e5 kHz) and a slightly higher upper limit of the audible frequency range. Both of these aspects would appear to be primitive features of the hearing abilities in the SH hominins.

o Length in Australopithecus and Paranthropus are well-predicted for their estimated BM and, thus, show the primitive condition for hominids.

o Ear evolved in a mosaic pattern in Homo

Question 44

When did 1:1 vocal tract emerge

Answer 44

• Lieberman stresses that Skhul did not have 1:1 so therefore even ‘modern’ humans did not have our speech capabilities
o This maybe true but see below – different type of speech – Lieberman also stresses that language arose before human vocal tract
 Perhaps with different species being able to communicate, there was a greater selective pressure to develop more efficient speech, even at the cost of greater choking risk

Question 45

Could hiedelbergensis speak

What did their anatomy for the evolution of speech

Answer 45

• Although SH humans did not have the 1:1 SVT proportion characteristic of adult modern humans, their vocal tracts were fully capable of producing the human quantal vowels
• the first step, already present H. heidelbergensis, represents a clear improvement beyond the communicative capacities of a chimpanzee. In turn, modern humans may represent a further specialization in the efficiency of oral communication - Although a ratio of SVTv:SVTh less than 1.0 does not prevent the production of human quantal vowels

o Absence of air sacs and presence of humanlike hyoid

Question 46

Why might language have evolved before human vocal tract

Answer 46

o Language may have begun to develop before presence of humanlike low larynx due to risk of choking

Question 47

Give a study linking language and tool-making skills in evolution

Answer 47

increased demands for effective visuomotor coordination and hierarchical action organization in more advanced toolmaking.

This includes an increased activation of ventral premotor and inferior parietal elements of the parieto-frontal praxis circuits in both the hemispheres and of the right hemisphere homologue of Broca’s area.

The observed patterns of activation and of overlap with language circuits suggest that toolmaking and language share a basis in more general human capacities for complex, goal-directed action.

Stout (2008)

Question 48

What did Haekel call the hypothetical ‘missing link’

Answer 48

Pithecanthropus alalus

instructed his students such as Richard and Oskar Hertwig to go and find it.

Question 49

How does Turkana Boy (KNM-WT 15000) compare to Lucy in vertebrae

Answer 49

Vertebrae: speech requires a complex coordination of breathing muscles to vary pitch and produce long sentences.
Lucy and Turkana boy’s relatively narrow spinal cord compared to modern humans indicates that they lacked the nerves responsible for this fine control of the muscles that coordinate breathing during speech.

Question 50

Evidence of language in chimps

Answer 50

chimps in Tai national park were able to organise vocal units into different structured sequences, possibly indicating different meanings - similar to sentence construction

Question 51

Describe the ossicles in Australopiths and Paranthropus

Inner ear?

Answer 51

all have human-like malleus –> deep origin

robustus’ incus is shaped so functionally has similar sensitivity to non-human haplorrhines

cochlear length predicted by body mass (ape-like)

Question 52

Describe the ossicles of Neanderthals

How does the middle ear differ for SH and Krapina Neanderthals

Answer 52

humans and N have different ossicle morphology but same functional outcome
different brain evolution but pressure to keep function same for language?

SH -> smaller CL suggests higher upper limit than humans but still shift away from chimps
Krapina (130kya) -> no significant difference between middle ear here and in humans