The wave-of-advance model was introduced to describe the spread of advantageous genes in a population. It can be adapted to model the uptake of any advantageous technology through a population, such as the arrival of neolithic farmers in Europe, the domestication of the horse, and the development of the wheel, iron tools, political organization, or advanced weaponry.

Any trait that preexists alongside the advantageous one could be carried along with it, such as genetics or language, regardless of any intrinsic superiority. Decoupling of the advantageous trait from other "hitchhiking" traits depends on its adoption by the preexisting population.

Here, we adopt a similar wave-of-advance model based on food production on a heterogeneous landscape with multiple populations. Two key results arise from geographic inhomogeneity: the "subsistence boundary," land so poor that the wave of advance is halted, and the temporary "diffusion boundary" where the wave cannot move into poorer areas until its gradient becomes sufficiently large. At diffusion boundaries, farming technology may pass to indigenous people already in those poorer lands, allowing their population to grow and resist encroachment by farmers.

Ultimately, this adoption of technology leads to the halt in spread of the hitchhiking trait and establishment of a permanent "cultural boundary" between distinct cultures with equivalent technology.

If you don't have access to PNAS, you can download a preprint of the paper.

For a visual demonstration:

This page contains the test site applet for the Neolithic farming simulation in an environment with a Gaussian shaped hill in the middle.

The upper panels show the populations of Farmers, Hunter Gatherers and converts as the wave travels from left to right. Populations are suppressed in the central region.

Lower panels show the integrated fraction of the various populations (white). With the default settings, the wave of advance of the farmers outcompetes the hunter-gatherers, a few converts are formed, but rapidly overwhelmed. The wave is it is slowed by the hills, and Shortly after crossing the hills the converts become the dominant population, with a sharp cultural boundary between them and the original Farmers.

The timestep is hardcoded at 1 year, and the length unit is 1km. For fast moving waves these fixed scales lead to a numerical instability in the diffusion equation, which could be fixed by reducing the timestep (at the expense of slowing the applet)

Cultural hitchhiking on the wave of advance of beneficial technologies

And to think I was just miles from this museum yesterday!

You come upon a pastoral scene undreamt of by any natural history museum. Two prehistoric children play near a burbling waterfall, thoroughly at home in the natural world. Dinosaurs cavort nearby, their animatronic mechanisms turning them into alluring companions, their gaping mouths seeming not threatening, but almost welcoming, as an Apatosaurus munches on leaves a few yards away.

What is this, then? A reproduction of a childhood fantasy in which dinosaurs are friends of inquisitive youngsters? The kind of fantasy that doesn’t care that human beings and these prefossilized thunder-lizards are usually thought to have been separated by millions of years? No, this really is meant to be more like one of those literal dioramas of the traditional natural history museum, an imagining of a real habitat, with plant life and landscape reproduced in meticulous detail.

Adam and Eve in the Land of the Dinosaurs

The central thesis of The Web's Awake is that the phenomenal growth and complexity of the web is beginning to outstrip our capability to control it directly. Many have worked on the concept of emergent properties within highly complex systems, concentrating heavily on the underlying mechanics concerned. Few, however, have studied the fundamentals involved from a sociotechnical perspective. In short, the virtual anatomy of the Web remains relatively uninvestigated. The Web's Awake attempts to seriously explore this gap, citing a number of provocative, yet objective, similarities from studies relating to both real world and digital systems. It presents a collage of interlinked facts, assertions, and coincidences, which boldly point to a Web with powerful potential for life.

The author, Philip Tetlow, is a researcher at IBM.

Read his paper, SOA, Glial and the Autonomic Semantic Web Machine, on developerWorks:

Our industry is drowning in a sea of complexity, with software complexity in particular causing significant complications. The natural sciences have been studying complexity for far longer that we could ever pretend. In many of these chaotic patterns, feedback is an essential component for the supporting mechanisms to be sustained. Such self-organising, or autonomic, systems are relatively commonplace in nature and many of their axiomatic workings have now been captured and formalised using abstract models. This paper therefore presents the proposition that such models may be used to address complexity issues within IT problem spaces. In particular it investigates the use of Semantic Web technologies as a means of reducing ambiguity in the design and implementation of automatic solutions for addressing complexity at a number of points in the Software Life Cycle. Additionally, Glial, an eXtensible Markup Language (XML) based prototype language, is introduced for the implementation of such autonomic solutions, including SOA systems.

Last year, the Web Science collaboration was launched by MIT and U. Southampton.

The Web's Awake: An Introduction to the Field of Web Science and the Concept of Web Life

Welcome to the Darwin Correspondence Project’s new web site. The main feature of the site is an Online Database with the complete, searchable, texts of around 5,000 letters written by and to Charles Darwin up to the year 1865. This includes all the surviving letters from the Beagle voyage - online for the first time - and all the letters from the years around the publication of Origin of species in 1859.

Darwin Correspondence Project

Looks like some good stuff here.

From cell biologists to quantum physicists, researchers are struggling to work out how systems involving large numbers of interacting entities work as a whole. In this collection of Essays, scientists explain how a systems approach, in parallel with the reductionism that dominated twentieth-century science, promises to yield fresh insight, and in some cases, to challenge the most widely held concepts of their field.

Subscription required for access to full text.

Connections: Essays in Nature

Some fundamental principles of colour vision, deduced from perceptual studies, have been understood for a long time. Physiological studies have confirmed the existence of three classes of cone photoreceptors, and of colour-opponent neurons that compare the signals from cones, but modern work has drawn attention to unexpected complexities of early organization: the proportions of cones of different types vary widely among individuals, without great effect on colour vision; the arrangement of different types of cones in the mosaic seems to be random, making it hard to optimize the connections to colour-opponent mechanisms; and new forms of colour-opponent mechanisms have recently been discovered. At a higher level, in the primary visual cortex, recent studies have revealed a simpler organization than had earlier been supposed, and in some respects have made it easier to reconcile physiological and perceptual findings.

This article is freely available (with registration).

The machinery of colour vision

Failure is a Good Thing.

A number of advocates have supported the establishment of an oath for life scientists as a way to address concerns about potential future bioterrorists.

Should life scientists make an oath ... that they will "do no harm" once they utter the hallowed words?

...

The main obstacle to becoming a physician is acceptance into medical school. Once accepted, students can perform poorly and still make it through the system, emerging on the other side to practice medicine on unsuspecting patients.

Unlike medical students who can repeat failed exams and courses many times, life sciences graduate students ... can fail ...

Failure makes you safer.

A code of conduct for the life sciences?

This is an edited version of a longer interview.

Benny Peiser of Liverpool John Moores University recently interviewed Freeman Dyson about his views on science, hope and the future.

...

Dyson: The principle of maximum diversity says that life evolves to make the universe as interesting as possible.

The principle of maximum diversity operates both at the physical and at the mental level. It says that the laws of nature and the initial conditions are such as to make the universe as interesting as possible. As a result, life is possible but not too easy. Always when things are dull, something new turns up to challenge us and to stop us from settling into a rut.

Examples of things which make life difficult are all around us: comet impacts, ice ages, weapons, plagues, nuclear fission, computers, sex, sin and death. Not all challenges can be overcome, and so we have tragedy. Maximum diversity often leads to maximum stress. In the end we survive, but only by the skin of our teeth.

-- Freeman Dyson, “Infinite in All Directions”

Peiser: How can young scientists develop intellectual independence and autonomy in a bureaucratic world of funding dependency?

Dyson: I like to remind young scientists of examples in the recent past when people without paper qualifications made great contributions. ... Amateurs and small companies will have a growing role in the future of science.

Peiser: How do you feel belonging to a tiny minority of scientists who dare to voice their doubts openly?

Dyson: I am always happy to be in the minority. Concerning the climate models, I know enough of the details to be sure that they are unreliable.

Dyson: Yes, the western academic world [today] is very much like Weimar Germany ...

Dyson: I see the discovery of HAR1 as a seminal event in the history of science, marking the beginning of a new understanding of human evolution and human nature.

Dyson: My view of the prevalence of doom-and-gloom in Cambridge is that it is a result of the English class system.

That last one is an interesting comment ...

Check out this RAND report:

Antisocial behavior is a costly and growing concern in the United Kingdom, with Britain’s Home Office logging around 66,000 reports of antisocial behavior each day. Vandalism alone is estimated to cost victims and the criminal justice system around £1.3 billion ($2.5 billion) annually. Other commonly reported forms of antisocial behavior include intimidation, drunkenness, begging, drug dealing, prostitution, rowdiness, graffiti, littering, and dumping rubbish in public places.

Rebel with a Cause: The Optimistic Scientist

“Listening to Noam Chomsky,” said a psychologist in her 50s, “always turns me on.”

This psychologist is by no means alone. A few months ago, in the Harvard Coop, a 20-something customer explained to her friends as they all walked past the cash registers, "I have such a crush on Noam Chomsky!"

A plethora of new findings, however, suggest that the experience of desire may be less a forerunner to sex than an afterthought, the cognitive overlay that the brain gives to the sensation of already having been aroused by some sort of physical or subliminal stimulus ...

Seeking the Keys ...

Nicholas Humphrey's latest book on the mystery of consciousness travelled with me to Crete, Latvia and America. And the intellectual journey it took me on has half-persuaded me that his evolutionary approach will one day provide an answer

'The mystery of consciousness' by Paul Broks | Prospect