computational complexity and the evolution of homo sapiens

Computational complexity and the

evolution of Homo sapiens

John F Hoffecker

Institute of Arctic and Alpine Research

University of Colorado at Boulder

American Anthropological Association

Washington DC • December 2014

HYPOTHESIS:

Homo sapiens is characterized by a faculty for

performing computations with symbols (words and

numbers) in the brain on a more complex level than

other forms of Homo.

The appearance of the modern human anatomy in the

fossil record reflects an increase in computational

complexity related to epigenetic changes in the timing

and pattern of early brain growth.

www.ks.uiuc.edu/Research/magsense/ms.html

computation in modern humans

sundaycomicsdebt.blogspot.com/2010/09/

“A complex train of thought can no more be carried on

without the aid of words, whether spoken or silent, than a

long calculation without the use of figures or algebra”

Charles Darwin (1871: 57–58)

“. . . the material structures of language both reflect,

and then systematically transform, our thinking and

reasoning about the world”

Andy Clark (2011: 59)

language as cognitive scaffolding

words & numbers = “material symbols”

“. . . the fundamental purpose of brains is to produce future”

Daniel C. Dennett (1991: 177)

kangaratmurdersoc.wordpress.com/2010/12/13/

“material symbols” of

language allow

computation about

objects and events

outside immediate

spatial and temporal

setting of individual

VOCALIZATIONS (WORDS AND NUMBERS)

SYNAPTIC CONNECTIONS (NEURONAL INFORMATION)

CODONS/BASE PAIR TRIPLETS (GENETIC INFORMATION)

how is complexity measured?

Simon (1962) proposed a

hierarchical measure of complex

systems

Chomsky (2006: 129)

syntactic language as computation

LEVEL 1

LEVEL 2

LEVEL 3

www.seawolfkayak.com/sb-workshops

gatesofthearctic.areaparks.com/

modern humans also perform

computations through visual-

tactile coordination of the

hands with material objects

as with the products of the

computations that underlie

syntactic language, artifacts and

features may exhibit a complex

hierarchical structure and

potentially infinite variations

LEVEL 1

LEVEL 2

LEVEL 3

Conard 2009: 248, fig. 1

LEVEL 1

LEVEL 2

LEVEL 3

adapted from Sato 2009: 33

Udehe snare (Russian Far East)

LEVEL 1

LEVEL 2

LEVEL 3

VOCALIZATIONS (WORDS AND NUMBERS)

SYNAPTIC CONNECTIONS (NEURONAL INFORMATION)

CODONS/BASE PAIR TRIPLETS (GENETIC INFORMATION)

alarm calls: matching sound and meaning

evolutionary roots of language in Homo

http://www.daviddarling.info/childrens_encyclopedia/Speak_Chimpanzee_Chapter2

http://open.jorum.ac.uk/xmlui/bitstream/handle/123456789/964/Items/SD226_2_section4

KNM-ER 1470: ~1.9 million years old

1470 endocast: reorganization of frontal lobe (third inferior

frontal convolution, Broca’s area) (Tobias 1987; Holloway 1995;

Falk et al. 2000)

early Homo expansion into less productive habitat ~2 mya

Dominguez-Rodrigo et al. 2010: 322, fig. 6

FLK Zinj main

excavation

(Leakey 1971)

Beekman and Lew

(2007) addressed

problem of “when

does it pay to

dance?”

● dancing beneficial

when it allows

colony to focus on

high-quality patches

ecological modeling & information-center foraging strategy:

honeybee colony foraging

Primary kin

Primary kin

Hill et al. 2011: 1288, fig. 2

Lieberman 2011:

505, fig. 12.9

Lalueza-Fox et al. 2011: 251, table 1

Lalueza-Fox et al. 2011: 251, table 1

“social brain hypothesis” (Dunbar 1996, 1998)

H. sapiens in sub-Saharan

Africa 200–75 ka

(1367–1510 cm3)

1250–1299 cm3

adapted from Lieberman 2011: 566, fig. 13.12a

Homo sapiens

(Jebel Irhoud, Morocco)

~160,000 years old

Smith et al. 2007: figs. 1 & fig. 2

Coqueugniot et al. 2004:

299–300, figs. 1 & 2

Homo erectus

(Modjokerto, Java)

~1.8 million years old

1.0–1.5 years old:

brain volume = 72–84%

Gunz et al. 2011: fig. 5

archaeology of the social brain

Clark 1993: 155, fig. 1 Bouzouggar et al. 2007:

9967, fig. 3

VOCALIZATIONS (WORDS AND NUMBERS)

SYNAPTIC CONNECTIONS (NEURONAL INFORMATION)

CODONS/BASE PAIR TRIPLETS (GENETIC INFORMATION)

NEW FORMS OF INFORMATION: WRITING etc.