Round-up: Music, Pinker & Bloom, tool use
I've been rather swamped this week, off to the NZ Phylogenetics Meeting in a few hours, and have to finish writing my talk. So - just a quick round-up of interesting links to keep you all occupied!
- Music reliably evokes common colors - a fascinating demo by cognitive daily.
- The great blog, Shared Symbolic Storage has a nice post on the influence of Steven Pinker and Paul Bloom's 1990 paper "Natural Language and Natural Selection":
The paper had a tremendous impact. In the open peer commentary, Jim Hurford (1990) hailed it as a "Liberation!" and saw it as the crucial step "Beyond the roadblock in linguistic evolution studies" most clearly represented by the 1866 ban on papers about language origin by the Linguistic Society of Paris and the rumored "Gentleman's Agreement" with a similar notion by the Linguistic Society of America (Indeed, no paper about the topic appeared in the society's journal, 'Language' until 2000 (Newmeyer 2003)), while Philip Lieberman (1990) (rightly) argued that he was making the same claim for years. To others, however, for example Richard Lewontin (Lewontin 1990: 740) and Massimo Piattelli-Palmarini (Piattelli-Palmarini 1990: 754), language still appeared as "a system of such complexity that its selective value [still was] difficult to imagine" (Studdert-Kennedy/Knight/Hurford 1998: 3)
-
A promising tool-use paper: Setting tool use within the context of animal construction behaviour:
Tool use and manufacture are given prominence by their rarity and suggested relation to human lineage. Here, we question the view that tool use is rare because cognitive abilities act as an evolutionary constraint and suggest that tools are actually seldom very useful compared with anatomical adaptations. Furthermore, we argue that focussing on animal tool use primarily in terms of human evolution can lead to important insights regarding the ecological and cognitive abilities of non-human tool users being overlooked. We argue that such oversight can best be avoided by examining tools within the wider context of construction behaviours by animals (such as nest building and trap construction).
Early human use of marine resources and pigment in South Africa during the Middle Pleistocene
Today in Nature, Early human use of marine resources and pigment in South Africa during the Middle Pleistocene:
Genetic and anatomical evidence suggests that Homo sapiens arose in Africa between 200 and 100 thousand years (kyr) ago and recent evidence indicates symbolic behaviour may have appeared approx135–75 kyr ago. From 195–130 kyr ago, the world was in a fluctuating but predominantly glacial stage (marine isotope stage MIS6); much of Africa was cooler and drier, and dated archaeological sites are rare.
Here we show that by approx 164 kyr ago (+/-12 kyr) at Pinnacle Point (on the south coast of South Africa) humans expanded their diet to include marine resources, perhaps as a response to these harsh environmental conditions. The earliest previous evidence for human use of marine resources and coastal habitats was dated to approx 125 kyr ago.
Coincident with this diet and habitat expansion is an early use and modification of pigment, probably for symbolic behaviour, as well as the production of bladelet stone tool technology, previously dated to post-70 kyr ago. Shellfish may have been crucial to the survival of these early humans as they expanded their home ranges to include coastlines and followed the shifting position of the coast when sea level fluctuated over the length of MIS6.
Boston Globe: How bird brains are shaking up science
Jonah Lehrer in The Boston Globe:
THE NEW CALEDONIAN crow is surprisingly smart about its food. Its favorite insects live in tiny crevices that are too narrow for its beak. So the crow takes a barbed leaf and, using its beak and claws, fashions a primitive hook. It then lowers the hook down into the cracks, almost like a man fishing, and draws up a rich meal. Some scientists even suggest that crows are more sophisticated tool builders than chimps, since they can transmit their knowledge on to successive generations and improve the tools over time. These birds have a culture.
Meta-tool use in New Caledonian Crows
Everyone thinks that chimpanzees and other primates are good candidates for finding complex cognitive capabilities in non-human animals. Unfortunately, they're just not that smart, really. Sure, they can use sticks to fish termites out of holes, however, there's another animal which can go a bit further.
The New Caledonian Crow (Corvus moneduloides) is known to manufacture a number of different tool types for to extract grubs from rotting logs. For example, they can trim down a twig into a fish-hook shaped device, or they slice off a strip of Pandanus leaf (a flax-like plant) and use the barbs on the leaf as hooks. The actions they go through here are far more complex than anything observed in any other non-human animal, including chimps.
Today, some good friends of mine Alex Taylor, Gavin Hunt, Jenny Holzhaider, and my boss, Russell Gray, have a paper out in Current Biology which shows that these crows can spontaneously use a tool, to get another tool, to get some food. This trick, known as "meta-tool use", is quite amazing as it suggests that the birds actually understand what's going on and have some form of analogical reasoning happening. This is a big deal - chimps, for example, often don't understand the physical properties of their tools (see for example, Daniel Povinelli's work on "Folk Physics"), but just appear to have learnt a sequence of actions.
To test this, Alex, Gavin, Jenny and Russell set up an experiment with two boxes containing tools; one short and one long. Only one of the tools could be used to get food out of a second box:
(image from Press Release [PDF])
Russell says:
Six out of seven birds tried to get the long stick with the short stick at their first attempt at solving the problem. To do this, they had to inhibit their normal response of trying to get the food directly with the short stick, and realize that they could use the short stick to get the long stick."
The website for this research group is here, and it has plenty of video clips, including this one, where Gypsy does the task the very FIRST time she sees it:
The abstract is available at Current Biology, "Spontaneous Metatool Use by New Caledonian Crows" (doi):
A crucial stage in hominin evolution was the development of metatool use—the ability to use one tool on another. Although the great apes can solve metatool tasks, monkeys have been less successful. Here we provide experimental evidence that New Caledonian crows can spontaneously solve a demanding metatool task in which a short tool is used to extract a longer tool that can then be used to obtain meat.
Six out of the seven crows initially attempted to extract the long tool with the short tool. Four successfully obtained meat on the first trial. The experiments revealed that the crows did not solve the metatool task by trial-and-error learning during the task or through a previously learned rule. The sophisticated physical cognition shown appears to have been based on analogical reasoning. The ability to reason analogically may explain the exceptional tool-manufacturing skills of New Caledonian crows.
Technorati Tags: crow, new caledonian crow, corvus, tool use