The Laws of the Web. Patterns in the Ecology of Information

Review of The Laws of the Web. Patterns in the Ecology of Information / Huberman, Bernardo A. The Laws of the Web. Patterns in the Ecology of Information. Cambridge, Mass: The MIT Press, 2001

The Metabolism and Growth of Web Forums

We view web forums as virtual living organisms feeding on user's attention and investigate how these organisms grow at the expense of collective attention. We find that the "body mass" ($PV$) and "energy consumption" ($UV$) of the studied forums exhibits the allometric growth property, i.e., $PV_t \sim UV_t ^ \theta$. This implies that within a forum, the network transporting attention flow between threads has a structure invariant of time, despite of the continuously changing of the nodes (threads) and edges (clickstreams). The observed time-invariant topology allows us to explain the dynamics of networks by the behavior of threads. In particular, we describe the clickstream dissipation on threads using the function $D_i \sim T_i ^ \gamma$, in which $T_i$ is the clickstreams to node $i$ and $D_i$ is the clickstream dissipated from $i$. It turns out that $\gamma$, an indicator for dissipation efficiency, is negatively correlated with $\theta$ and $1/\gamma$ sets the lower boundary for $\theta$. Our findings have practical consequences. For example, $\theta$ can be used as a measure of the "stickiness" of forums, because it quantifies the stable ability of forums to convert $UV$ into $PV$, i.e., to remain users "lock-in" the forum. Meanwhile, the correlation between $\gamma$ and $\theta$ provides a convenient method to evaluate the `stickiness" of forums. Finally, we discuss an optimized "body mass" of forums at around $10^5$ that minimizes $\gamma$ and maximizes $\theta$.Comment: 6 figure

Scaling Behaviors of Weighted Food Webs as Energy Transportation Networks

Food webs can be regarded as energy transporting networks in which the weight of each edge denotes the energy flux between two species. By investigating 21 empirical weighted food webs as energy flow networks, we found several ubiquitous scaling behaviors. Two random variables $A_i$ and $C_i$ defined for each vertex $i$, representing the total flux (also called vertex intensity) and total indirect effect or energy store of $i$, were found to follow power law distributions with the exponents $\alpha\approx 1.32$ and $\beta\approx 1.33$, respectively. Another scaling behavior is the power law relationship, $C_i\sim A_i^\eta$, where $\eta\approx 1.02$. This is known as the allometric scaling power law relationship because $A_i$ can be treated as metabolism and $C_i$ as the body mass of the sub-network rooted from the vertex $i$, according to the algorithm presented in this paper. Finally, a simple relationship among these power law exponents, $\eta=(\alpha-1)/(\beta-1)$, was mathematically derived and tested by the empirical food webs

A review of data on abundance, trends in abundance, habitat use and diet of ice-breeding seals in the Southern Ocean

The development of models of marine ecosystems in the Southern Ocean is becoming increasingly important as a means of understanding and managing impacts such as exploitation and climate change. Collating data from disparate sources, and understanding biases or uncertainties inherent in those data, are important first steps for improving ecosystem models. This review focuses on seals that breed in ice habitats of the Southern Ocean (i.e. crabeater seal, Lobodon carcinophaga; Ross seal, Ommatophoca rossii; leopard seal, Hydrurga leptonyx; and Weddell seal, Leptonychotes weddellii). Data on populations (abundance and trends in abundance), distribution and habitat use (movement, key habitat and environmental features) and foraging (diet) are summarised, and potential biases and uncertainties inherent in those data are identified and discussed. Spatial and temporal gaps in knowledge of the populations, habitats and diet of each species are also identified

Understanding evolutionary processes during past Quaternary climatic cycles: Can it be applied to the future?

Climate change affected ecological community make-up during the Quaternary which was probably both the cause of, and was caused by, evolutionary processes such as species evolution, adaptation and extinction of species and populations

The Living World in the curriculum: ecology, an essential part of biology learning

Argues that biology should be learnt in the living world not in the classroom. Field ecological education is essential. Ecology is ideal candidate for implementing proposed transformations in science curricula. Ecology education is the missing link in educational reform . Crucial in developing biological literacy for citizen

Web Science emerges

The relentless rise in Web pages and links is creating emergent properties, from social networks to virtual identity theft, that are transforming society. A new discipline, Web Science, aims to discover how Web traits arise and how they can be harnessed or held in check to benefit society. Important advances are beginning to be made; more work can solve major issues such as securing privacy and conveying trust

The strategic and the stratigraphic: a working paper on the dynamics of organisational evolution.

Despite large debates over fundamental issues a broadly evolutionary paradigm of organisations is growing in legitimacy. It may though be preferable to replace the metaphor of the organisation as an organism with the literal assertion that both social organisations are ecologies (Weeks and Galunic, 2003). They are still classes of complex systems maintained, and specified by, replicators (or schemata Gell Mann 1994) but the interactor is not necessarily the individual organisation, or population of organisations. Conceptual evolution has been argued as a post-Kuhnian analysis of the scientific process (Hull 1988), a rival economic paradigm (references in Hodgson 1993), a view of strategy (e.g. Lloyd 1990) and an explanation of organisational transformation and learning (Price and Evans 1993, Price 1994, 1995).My concern in this paper is to compare strategic extinction and speciation events in both systems. The stratigraphic record shows a dominant pattern of extinctions and radiative speciations which then settle to stabilised ecosystems. The historical and commercial (or strategigraphic?) record illustrates a similar pattern (Rothschild 1990, Tylecote 1993, Arthur 1994). The causes of extinction events may be genuinely external to the system affected (e.g. asteroid impacts interrupting a reptilian dominated system cannot plausibly be traced to feedback processes in any coupled eco/ lithosphere) or they may be internal when the success of a particular replicator system disturbs a wider systemic balance (e.g. ice-house glaciations terminating plant dominated episodes of earth history). Strategic scale parallels of both forms of extinction event can be seen in commercial and technological history. Keywords Organisational evolution, Punctuated equilibrium, Narrative ecology, memetics