August 19, 2016

From Toy Models to Quantifying Mosaic Development

Time travel in the Terminator metaverse. COURTESY: Michael Talley.

Almost two years ago, Richard Gordon and I published a paper in the journal Biosystems called "Toy Models for Macroevolutionary Patterns and Trends" [1]. Now, almost exactly two years later [2], we have published a second paper (not quite a follow-up) called "Quantifying Mosaic Development: towards an evo-devo postmodern synthesis of the evolution of development via differentiation trees of embryos". While the title is quite long, the approach can be best described as computational/ statistical evolution of development (evo-devo).

Sketch of a generic differentiation tree, which figures prominently in our theoretical synthesis and analysis. COURTESY: Dr. Richard Gordon.

This paper is part of a special issue in the journal Biology called "Beyond the Modern Evolutionary Synthesis- what have we missed?" and a product of the DevoWorm project. The paper itself is a hybrid theoretical synthesis/research report, and introduces a variety of comparative statistical and computational techniques [3] that are used to analyze quantitative spatial and temporal datasets representing early embryogenesis. Part of this approach was previewed in our most recent public lecture to the OpenWorm Foundation.

The comparative data analysis involves investigations within and between two species from different parts of the tree of life: Caenorhabditis elegans (Nematode, invertebrate) and Ciona intestinalis (Tunicate, chordate). The main comparison involves different instances of early mosaic development, or a developmental process that is deterministic with respect to cellular fate. We also reference data from the regulative developing Axolotl (Amphibian, vertebrate) in one of the analyses. All of the analyses involve the reuse and analysis of secondary data, which is becoming an important part of the scientific process for many research groups.

One of the techniques featured in the paper is an information-theoretic technique called information isometry [4]. This method was developed within the DevoWorm group, and uses a mathematical representation called an isometric graph to visualize cell lineages organized in different ways (e.g. a lineage tree vs. a differentiation tree). This method is summarized and validated in our paper "Information Isometry Technique Reveals Organizational Features in Developmental Cell Lineages" [4]. Briefly, each level of the cell lineage is represented as an isoline, which contains points of a specific Hamming distance. The Hamming distance is the distance between that particular cell in two alternative cell lineage orderings (the forementioned lineage and differentiation trees).

An example of an isometric graph from Caenorhabditis elegans, taken from Figure 12 in [5]. The position of a point representing a cell is based on the depth of its node in the cell lineage. The positions of all points are rotated 45 degrees clockwise from a bottom-to-top differentiation tree (in this case) ordering, where the one-cell stage is at the bottom of the graph.

A final word on the new Biology paper as it related to the use of references. Recently, I ran across a paper called "The Memory of Science: Inflation, Myopia, and the Knowledge Network" [6], which introduced me to the statistical definition of citation age. This inspired me to calculate the citation age of all journal references from three papers: Toy Models, Quantifying Mosaic Development, and a Nature Reviews Neuroscience paper from Bohil, Alicea (me), and Biocca, published in 2011. This was used as an analytical control -- as it is a review, it should contain papers which are older than the contemporary literature. Here are the age distributions for all three papers.

Distribution of Citation Ages from "Toy Models for Macroevolutionary Patterns and Trends" (circa 2014).

Distribution of Citation Ages from "Quantifying Mosaic Development: Towards an Evo-Devo Postmodern Synthesis of the Evolution of Development Via Differentiation Trees of Embryos" (circa 2016).

Distribution of Citation Ages from "Virtual Reality in Neuroscience Research and Therapy" (circa 2011).

What is interesting here is that both "Toy Models" and "Quantifying Mosaic Development" show a long tail with respect to age, while the review article shows very little in terms of a distributional tail. While there are differences in topical literatures (the VR and associated perceptual literature is not that old, after all) that influence the result, it seems that the recurrent academic Terminators utilize the literature in a way somewhat differently than most contemporary research papers. While the respect for history is somewhat author and topically dependent, it does seem to add a extra dimension to the research.

[1] the Toy Models paper was part of a Biosystems special issue called "Patterns in Evolution".

[2] This is a Terminator metaverse reference, in which the Terminator comes back every ten years to cause, effect, and/or stop Judgement Day.

[3] Gittleman, J.L. and Luh, H. (1992). On Comparing Comparative Methods. Annual Review of Ecology and Systematics, 23, 383-404.

[4] Alicea, B., Portegys, T.E., and Gordon, R. (2016). Information Isometry Technique Reveals Organizational Features in Developmental Cell Lineages. bioRxiv, doi:10.1101/062539

[5] Alicea, B. and Gordon, R. (2016). Quantifying Mosaic Development: Towards an Evo-Devo Postmodern Synthesis of the Evolution of Development Via Differentiation Trees of Embryos. Biology, 5(3), 33.

[6] Pan, R.K., Petersen, A.M., Pammolli, F., and Fortunato, S. (2016). The Memory of Science: Inflation, Myopia, and the Knowledge Network. arXiv, 1607.05606.

August 3, 2016

Slate and the Solitary Ethnographic Diagram

While his style and message does not resonate with me at all, I've always thought that Donald Trump's speeches were highly-structured rhetoric. He seems to be using a form of intersubjective signaling [1] understood by a number of constituencies as communicating their values in an authentic manner. Specifically, the speeches have a sentence structure and cadence that can be differentiated from the literalism of contemporary mainstream society or more traditional forms of doublespeak ubiquitous in American politics.

This is why the most recent challenge from Slate Magazine was too good to pass up. The challenge (which has the feel of a Will Shortz challenge): diagram a passage from a Donald Trump speech given on July 21 in Sun City, South Carolina. The passage is as follows:
"Look, having nuclear—my uncle was a great professor and scientist and engineer, Dr. John Trump at MIT; good genes, very good genes, OK, very smart, the Wharton School of Finance, very good, very smart—you know, if you’re a conservative Republican, if I were a liberal, if, like, OK, if I ran as a liberal Democrat, they would say I’m one of the smartest people anywhere in the world—it’s true!—but when you’re a conservative Republican they try—oh, do they do a number—that’s why I always start off: Went to Wharton, was a good student, went there, went there, did this, built a fortune—you know I have to give my like credentials all the time, because we’re a little disadvantaged—but you look at the nuclear deal, the thing that really bothers me—it would have been so easy, and it’s not as important as these lives are (nuclear is powerful; my uncle explained that to me many, many years ago, the power and that was 35 years ago; he would explain the power of what’s going to happen and he was right—who would have thought?), but when you look at what’s going on with the four prisoners—now it used to be three, now it’s four—but when it was three and even now, I would have said it’s all in the messenger; fellas, and it is fellas because, you know, they don’t, they haven’t figured that the women are smarter right now than the men, so, you know, it’s gonna take them about another 150 years—but the Persians are great negotiators, the Iranians are great negotiators, so, and they, they just killed, they just killed us"
Okay, here you go -- an ethnographic-style diagram [2] based on one man, but perhaps instructive of an entire American subculture (click to enlarge). The diagram focuses on the relationship between John and Donald Trump (context-specific braintrust) and a specific worldview of power wielded through nuclear weapons, financial ability, and persuasion.

[1] In this case, intersubjective signaling could be used as a mechanism to reinforce group cohesion, particularly when the group's belief structure is defined by epistemic closure.

[2] Perceived lack of agency shown as red arcs terminated with a dot.

August 1, 2016

Reaction to the Future, part infinity

Alvin Toffler, futurist and author of Future Shock and The Third Wave, died recently at the age of 87. Future Shock and The Third Wave [1] were favorite books of mine when I was in High School, and contains a lot of unexplored themes. The book's main argument was that rapid technological change is accompanied by a number of negative social effects, including reactionary political movements and collective psychocultural responses. As the rate and scope of technological change has increased [2], this shock to human society has become more acute [3]. The Thrid Wave was more directly related to cultural change, and assumed that major observed  transitions in cultural evolution [4] required profound shifts in sociology, economics, and psychology.

We can see this effect in our own society, particularly with respect to the economy of mind. As a cultural trend, more young people are pursuing a life of creative and/or mental productivity [5]. While some of this productivity is tangible (see the contemporary focus on applications of University research),  In particular, there is a strain of austerity thinking [6] that has arisen since 2008 which views intellectual expertise more generally and academic activity more specifically as a superfluous fraud. Since many of these pursuits require public (government) funding and/or provide no immediate tangible return, there is ideological bias at play as well. More generally, future shock can manifest itself as a revolt against modernity.

The blogger Drugmonkey, advancing the Mellon Doctrine (among other types of reactionary thinking) in the realm of biomedical science. 

Don't be a neo-reactionary! Hint: you don't need to appeal to religion to take this point of view.

The legacy of Toffler's ideas have gotten a bit muddled [7], and in exposed one of the problems with futurism: namely, it is hard to discern solid predictions from quasi-religious pronouncements. The unfortunate event of Toffler's death also coincides with the 50th Anniversary of the first episode of Star Trek (circa 1966). Star Trek's prime directive is an interesting detail of the Starfleet Academy rulebook consistent with Toffler's argument. The prime directive is more directly related to cultural evolution, and states that Starfleet cannot interfere in the normal trajectory of a given culture's development [8]. It is not clear how this works in practice, however, since mere cultural contact can change the trajectory of cultural evolution more than simple exposure to various foreign technologies [9]. On the other hand, if they are adopted, the introduction of single tools or cultural practices can have profound effects on a culture's trajectory.

This concept will take a long time to become culturally consistent. How long? Probably much longer than predicted by Gene Roddenbery (creator of Star Trek).

Some people who might argue that Toffler and Roddenbery are simply products of their era (the 20th century, a period of rapid technological change). Their views on the outcomes of change (technological advancement and modern cultural mores) are biased towards a historical positivism. In other words, progressive technological change is inevitable, even if we mediate this path to eventual enlightenment. Yet this view ignores the basic outlines of historical complexity -- that cultural and technological complexity does tend to increase, even if the process is painful, chaotic, and uneven [10].

[1] Toffler, A.   Future Shock. Random House, 1970 AND Toffler, A.   The Third Wave. Bantam Books, 1980.

[2] this is not necessarily equivalent to the rate of innovation, but rather has to do with the dynamics of technology adoption. For those of you who are familiar with early period (pre-2005) Wired magazine, ideological constructions around the term "neo-Luddite" characterizes the cultural aspect of this effect. For more, please see: Katz, J.   Return of the Luddites. Wired, June 1, 1995.

[3] this can be observational (such as noticing the preponderance of payphones in an several-decades old movie) or more profound (such as automation-related job losses).

[4] the major transitions of cultural evolution may or may not result from directional trends in cultural complexity.

[5] AKA The "yuccie" manifesto. For more, please see: Infante, D.   The hipster is dead, and you might not like who comes next. Mashable, June 09, 2015.

[6] Austerity thinking is associated with an obsession with debt which is underlain by a number of cultural and epistemic biases. There are a number of cultural antecedents that stress the connections between debt and morality, while most if not all cultural traditions are ill-equipped to deal with the logic and technical details of modern economics and finance. This latter point (an incompatibility between cultural traditions and advanced technology) was addressed in the book "Technopoly" by Neil Postman. A similar conceptual gap is also seen amongst popular responses to technologies such as genetic modification, which comes into conflict with many traditional cultural themes involving cleanliness and purity.

[7] There is a fascinating political subtext to how Toffler's ideas played out in society, namely his association with Newt Gingrich and anti-neo-luddite politics in the 1990s. Not particularly in line with Toffler's own views, but definitely a study in historical context. For more, please see: Murphy, T. Newt's New-Age Love Gurus. Mother Jones, January 30, 2012.

[8] For one interesting dissent on the optimality of the prime directive, please see: Clint, E.   The Prime Directive: Star Trek’s doctrine of moral laziness. Skeptic Ink blog, November 4, 2012.

[9] This statement is consistent with a process called "trans-cultural diffusion". For more, please see. Albrecht, K.   Trans-cultural diffusion. September 13, 2013.

[10] The essential lesson from the emerging field of cliodynamics. For more, please see: Turchin, P.   Arise 'cliodynamics'. Nature, 454, 34-35 (2008).