Tag: bipedalism

New Book. New Ideas?

A new book is to be published on May the 24th. By John F. Hoffecker the book is entitled “Landscape of the Mind: Human Evolution and the Archaeology of Thought” – it aims to look at the emergence of human thought and language through archaeological evidence

Archeologists often struggle to find fossil evidence pertaining to the evolution of the brain. Thoughts are a hard thing to fossilize. However, John Hoffecker claims that this is not the case and fossils and archaeological evidence for the evolution of the human mind are abundant.

Hoffecker has developed a concept which he calls the “super-brain” which he hypothesises emerged in Africa some 75,000 years ago. He claims that human’s ability to share thoughts between individuals is analogous to the abilities of honey bees who are able to communicate the location of food both in terms of distance and direction. They do this using a waggle-dance. Humans are able to share thoughts between brains using communicative methods, the most obvious of these being language.

Fossil evidence for the emergence of speech is thin on the ground and, where it does exist, is quite controversial. However, symbols emerging in the archaeological record coincides with an increase in evidence of creativity being displayed in many artifacts from the same time. Creative, artistic designs scratched on mineral pigment show up in Africa about 75,000 years ago and are thought to be evidence for symbolism and language

Hoffecker also hypothesises that his concept of the super-brain is likely to be connected to things like bipedalism and tool making. He claims that it was tool making which helped early humans first develop the ability to represent complex thoughts to others.

He claims that tools were a consequence of bipedalism as this freed up the hands to make and use tools. Hoffecker pin points his “super-brain” as beginning to emerge 1.6 million years ago when the first hand axes began to appear in the fossil record. This is because hand axes are thought to be an external realisation of human thought as they bear little resemblance to the natural objects they were made from.

By 75,00 years ago humans were producing perforated shell ornaments, polished bone awls and simple geometric designs incised into lumps of red ochre.

Humans are known to have emerged from Africa between 60,00 to 50,000 years ago based on archeological evidence. Hoeffecker hypothesises that – “Since all languages have basically the same structure, it is inconceivable to me that they could have evolved independently at different times and places.”

Hoeffecker also lead a study in 2007 that discovered a carved piece of mammoth ivory that appears to be the head of a small figurine dating to more than 40,000 years ago. This is claimed to be the oldest piece of figurative art ever discovered. Finds like this illustrate the creative mind of humans as they spread out of Africa.

Figurative art and musical instruments which date back to before 30,000 years ago have also been discovered in caves in France and Germany.

This looks to be nothing new but archaeological evidence is something which a lot of people interested in language evolution do not often discuss. I also don’t really know what to think of Hoeffecker’s claim that “all languages basically have the same structure”. What do you think?

Bipedalism: New Fossil Evidence and Language Evolution

Published in Science today, 11.02.2011 (yey! palidromic date!) is a report on the find of a Complete Fourth Metatarsal and Arches in the Foot of Australopithecus afarensis.

New fossil evidence from Hadar, Ethiopia suggests that our ancestors from 3.2 million years ago (Australopithecus afarensis (better known as Lucy)) had arches in their feet.

Arched feet are an essential part of the bipedal way that modern humans walk.

Although the skeleton of Lucy was found in 1974, until now important foot bones in all of the specimens uncovered to date have made it difficult for researchers to understand precisely how well adapted for bipedalism a. afarensis were.

Why should people interested in Language Evolution care about bipedalism? Well, here’s some food for thought:

1) Bipedalism likely had an impact on our cognitive abilities. As climbing as a form of locomotion became less common, different ways to cognitively represent space and distance probably had to be found. These new systems could have involved imitation (mirror neuron alarm bells start ringing). By adding imitative abilities to already existing spacial awareness that are seen in modern, non-human primates, this may have created mechanisms which allowed hominins to visualise themselves walking across plains (McWhinney 2005). This may have been the original selective pressure for imitative ability and therefore could have some implications for the imitative abilities which exist within language.

2) Upright posture would free up forelimbs which may have had communicative advantages as it would free the hands up for gesture. This theory has been somewhat rubished in that  the first apes to adapt a bipedal posture were probably cognitively not much different from today’s apes (assumed from evidence of skull size). However even if this was not the selective pressure FOR bipedalism it doesn’t stop it being relevant to the discussion.

3) Free hand movement would also lead to making tools. Stone tools getting more complex and language developing as evolution took place may show a close relationship between enhanced motor movement and language. Deficits in motor control are also often linked to aphasia so there is a strong connection between manual activity and speech communication.

4) When Chimpanzees and Gorillas are socializing in groups they go from a ‘knuckle walk’ to sitting in circles, this allows apes to keep eye contact with each other in social situations,  bipedalism would also allow one to keep eye contact at all times, even when in motion, and so the this may have been a selective pressure. Stanford (2003)

5) Evolution of the cortico-striatal neural circuits (basal ganglia) that regulate human language may have been shaped by the demands of upright bipedal locomotion. (Lieberman, 2001)

A lot of this debate is quite controversial but I thought I’d put some thoughts/theories out there in celebration of exciting new finds!

References

Lieberman, P. (2001) On the subcortical bases of the evolution of language. In Jurgan Trabant and Sean Ward, editors, New Essays on the Origins of Language, pages 21–40. Berlin-New York:Mouton de Gruyter.

McWhinney, B. (2005) Language Evolution and Human Development. In Bjorklund, D. and Pellegrini, A. (Eds.). Origins of the Social Mind: Evolutionary Psychology and Child Development (pp 383-410). New York: Guilford Press.

Stanford, C. B. (2003). Upright: The evolutionary key to becoming human. New York: Houghton Mifflin

Ward, C. V., W. H. Kimbel & D. C. Johanson (2011) Complete Fourth Metatarsal and Arches in the Foot of Australopithecus afarensis. Science: 331 (6018), 750-753.