martes, 15 de octubre de 2013

War, space, and the evolution of Old World complex societies

How did human societies evolve from small groups, integrated by face-to-face cooperation, to huge anonymous societies of today? Why is there so much variation in the ability of different human populations to construct viable states? We developed a model that uses cultural evolution mechanisms to predict where and when the largest-scale complex societies should have arisen in human history. The model was simulated within a realistic landscape of the Afroeurasian landmass, and its predictions were tested against real data. Overall, the model did an excellent job predicting empirical patterns. Our results suggest a possible explanation as to why a long history of statehood is positively correlated with political stability, institutional quality, and income per capita.

War, space, and the evolution of Old World complex societies
Peter Turchin, Thomas E. Currie, Edward A. L. Turner, and Sergey Gavrilets


The detection of intermediate-level emergent structures and patterns

Artificial life is largely concerned with systems that exhibit different emergent phenomena; yet, the identification of emergent structures is frequently a difficult challenge. In this paper we introduced a system to identify candidate emergent mesolevel dynamical structures in dynamical networks. This method is based on an extension of a measure introduced for detecting clusters in biological neural networks; its main novelty in comparison to previous application of similar measures is that we used it to consider truly dynamical networks, and not only fluctuations around stable asymptotic states. The identified structures are clusters of elements that behave in a coherent and coordinated way and that loosely interact with the remainder of the system. We have evidence that our approach is able to identify these "emerging things" in some artificial network models and in more complex data coming from catalytic reaction networks and biological gene regulatory systems (A.thaliana). We think that this system could suggest interesting new ways in dealing with artificial and biological systems.

The detection of intermediate-level emergent structures and patterns Marco Villani, Alessandro Filisetti, Stefano Benedettini, Andrea Roli, David Avra Lane, Roberto Serrae
ECAL 2013 Best Paper Award


viernes, 23 de agosto de 2013

Life as we know it

This paper presents a heuristic proof (and simulations of a primordial soup) suggesting that life—or biological self-organization—is an inevitable and emergent property of any (ergodic) random dynamical system that possesses a Markov blanket. This conclusion is based on the following arguments: if the coupling among an ensemble of dynamical systems is mediated by short-range forces, then the states of remote systems must be conditionally independent. These independencies induce a Markov blanket that separates internal and external states in a statistical sense. The existence of a Markov blanket means that internal states will appear to minimize a free energy functional of the states of their Markov blanket. Crucially, this is the same quantity that is optimized in Bayesian inference. Therefore, the internal states (and their blanket) will appear to engage in active Bayesian inference. In other words, they will appear to model—and act on—their world to preserve their functional and structural integrity, leading to homoeostasis and a simple form of autopoiesis.

Life as we know it
Karl Friston

J. R. Soc. Interface 6 September 2013 vol. 10 no. 86 20130475

miércoles, 17 de julio de 2013

Self-extinction through optimizing selection

Evolutionary suicide is a process in which selection drives a viable population to extinction. So far, such selection-driven self-extinction has been demonstrated in models with frequency-dependent selection.


Constraint and Contingency in Multifunctional Gene Regulatory Circuits


Many essential biological processes, ranging from embryonic patterning to circadian rhythms, are driven by gene regulatory circuits, which comprise small sets of genes that turn each other on or off to form a distinct pattern of gene expression. Gene regulatory circuits often have multiple functions. This means that they can form different gene expression patterns at different times or in different tissues. We know little about multifunctional gene regulatory circuits. For example, we do not know how multifunctionality constrains the evolution of such circuits, how many circuits exist that have a given number of functions, and whether tradeoffs exist between multifunctionality and the robustness of a circuit to mutation. Because it is not currently possible to answer these questions experimentally, we use a computational model to exhaustively enumerate millions of regulatory circuits and all their possible functions, thereby providing the first comprehensive study of multifunctionality in model regulatory circuits. Our results highlight limits of circuit designability that are relevant to both systems biologists and synthetic biologists.
 
Payne JL, Wagner A (2013) Constraint and Contingency in Multifunctional Gene Regulatory Circuits. PLoS Comput Biol 9(6): e1003071.http://dx.doi.org/10.1371/journal.pcbi.1003071

Can Life Evolve from Wires and Plastic?


In a laboratory tucked away in a corner of the Cornell University campus, Hod Lipson’s robots are evolving. He has already produced a self-aware robot that is able to gather information about itself as it learns to walk.
 
Hod Lipson reports: "We wrote a trivial 10-line algorithm, ran it on big gaming simulator, put it in a big computer and waited a week. In the beginning we got piles of junk. Then we got beautiful machines. Crazy shapes. Eventually a motor connected to a wire, which caused the motor to vibrate. Then a vibrating piece of junk moved infinitely better than any other… eventually we got machines that crawl. The evolutionary algorithm came up with a design, blueprints that worked for the robot."
 
The computer-bound creature transferred from the virtual domain to our world by way of a 3D printer. And then it took its first steps. Was this arrangement of rods and wires the machine-world’s equivalent of the primordial cell? Not quite: Lipson’s robot still couldn’t operate without human intervention. ‘We had to snap in the battery,’ he told me, ‘but it was the first time evolution produced physical robots. Eventually, I want to print the wires, the batteries, everything. Then evolution will have so much freedom. Evolution will not be constrained.’
 
Not many people would call creatures bred of plastic, wires and metal beautiful. Yet to see them toddle deliberately across the laboratory floor, or bend and snap as they pick up blocks and build replicas of themselves, brings to mind the beauty of evolution and animated life.
 
One could imagine Lipson’s electronic menagerie lining the shelves at Toys R Us, if not the CIA, but they have a deeper purpose. Lipson hopes to illuminate evolution itself. Just recently, his team provided some insight into modularity—the curious phenomenon whereby biological systems are composed of discrete functional units.
 
Though inherently newsworthy, the fruits of the Creative Machines Lab are just small steps along the road towards new life. Lipson, however, maintains that some of his robots are alive in a rudimentary sense. ‘There is nothing more black or white than alive or dead,’ he said, ‘but beneath the surface it’s not simple. There is a lot of grey area in between.’
 
The robots of the Creative Machines Lab might fulfill many criteria for life, but they are not completely autonomous—not yet. They still require human handouts for replication and power. These, though, are just stumbling blocks, conditions that could be resolved some day soon—perhaps by way of a 3D printer, a ready supply of raw materials, and a human hand to flip the switch just the once.
 
According to Lipson, an evolvable system is ‘the ultimate artificial intelligence, the most hands-off AI there is, which means a double edge. All you feed it is power and computing power. It’s both scary and promising.’ What if the solution to some of our present problems requires the evolution of artificial intelligence beyond anything we can design ourselves? Could an evolvable program help to predict the emergence of new flu viruses? Could it create more efficient machines? And once a truly autonomous, evolvable robot emerges, how long before its descendants make a pilgrimage to Lipson’s lab, where their ancestor first emerged from a primordial soup of wires and plastic to take its first steps on Earth?

In the light of evolution VII: The human mental machinery

This collection of colloquium papers aims to survey what has been learned about the human “mental machinery” since Darwin's insights. The colloquium brought together leading scientists who have worked on brain and mental traits. Their 16 contributions focus the objective of better understanding human brain processes, their evolution, and their eventual shared mechanisms with other animals. The articles are grouped into three primary sections: current study of the mind/brain relationships; the primate evolutionary continuity; and the human difference: from ethics to aesthetics.
 
In the light of evolution VII: The human mental machinery
Camilo J. Cela-Conde, Raúl Gutiérrez Lombardo, John C. Avise, and Francisco J. Ayala
http://dx.doi.org/10.1073/pnas.1307207110 
PNAS June 18, 2013 vol. 110 no. Supplement 2 10339-10342

Earth is surrounded by a 'bubble' of live bacteria - at 33 000 feet


Earth’s upper atmosphere—below freezing, nearly without oxygen, flooded by UV radiation—is no place to live. But last winter, scientists from the Georgia Institute of Technology discovered that billions of bacteria actually thrive up there. Expecting only a smattering of microorganisms, the researchers flew six miles above Earth’s surface in a NASA jet plane. There, they pumped outside air through a filter to collect particles. Back on the ground, they tallied the organisms, and the count was staggering: 20 percent of what they had assumed to be just dust or other particles was alive. Earth, it seems, is surrounded by a bubble of bacteria.
 
Scientists don’t yet know what the bacteria are doing up there, but they may be essential to how the atmosphere functions, says Kostas Konstantinidis, an environmental microbiologist on the Georgia Tech team. For example, they could be responsible for recycling nutrients in the atmosphere, like they do on Earth. And similar to other particles, they could influence weather patterns by helping clouds form. However, they also may be transmitting diseases from one side of the globe to the other. The researchers found E. coli in their samples (which they think hurricanes lifted from cities), and they plan to investigate whether plagues are raining down on us. If we can find out more about the role of bacteria in the atmosphere, says Ann Womack, a microbial ecologist at the University of Oregon, scientists could even fight climate change by engineering the bacteria to break down greenhouse gases into other, less harmful compounds.

jueves, 3 de enero de 2013


Adapting to a warmer world: No going back

Just a decade ago, 'adaptation' was something of a dirty word in the climate arena — an insinuation that nations could continue with business as usual and deal with the mess later. But greenhouse-gas emissions are increasing at an unprecedented rate and countries have failed to negotiate a successor to the Kyoto Protocol climate treaty. That stark reality has forced climate researchers and policy-makers to explore ways to weather some of the inevitable changes.
Descripción: http://www.scoop.it/rv?p=3596482547&tp=Topic



On the Foundations of the Theory of Evolution
Darwinism conceives evolution as a consequence of random variation and natural selection, hence it is based on a materialistic, i.e. matter-based, view of science inspired by classical physics. But matter in itself is considered a very complex notion in modern physics. More specifically, at a microscopic level, matter and energy are no longer retained within their simple form, and quantum mechanical models are proposed wherein potential form is considered in addition to actual form. In this paper we propose an alternative to standard Neodarwinian evolution theory. We suggest that the starting point of evolution theory cannot be limited to actual variation whereupon is selected, but to variation in the potential of entities according to the context. We therefore develop a formalism, referred to as Context driven Actualization of Potential (CAP), which handles potentiality and describes the evolution of entities as an actualization of potential through a reiterated interaction with the context.

On the Foundations of the Theory of Evolution
Diederik Aerts, Stan Bundervoet, Marek Czachor, Bart D'Hooghe, Liane Gabora, Philip Polk, Sandro Sozzo


Is Science Mostly Driven by Ideas or by Tools?
We are standing now as we stood in the 1950s, between a Kuhnian dream of sudden illumination and a Galisonian reality of laborious exploring. On one side are string theory and speculations about multiverses; on the other are all-sky surveys and observations of real black holes. The balance today is more even than it was in the 1950s. String theory is a far more promising venture than Einstein's unified field theory. Kuhn and Galison are running neck and neck in the race for glory. We are lucky to live in a time when both are going strong.

Is Science Mostly Driven by Ideas or by Tools?
Freeman J. Dyson
Science 14 December 2012: 
Vol. 338 no. 6113 pp. 1426-1427 
http://dx.doi.org/10.1126/science.1232773Descripción: http://www.scoop.it/rv?p=3718006105&tp=Topic


Individual memory and the emergence of cooperation

The social brain hypothesis states that selection pressures associated with complex social relationships have driven the evolution of sophisticated cognitive processes in primates. We investigated how the size of cooperative primate communities depends on the memory of each of its members and on the pressure exerted by natural selection. To this end we devised an evolutionary game theoretical model in which social interactions are modelled in terms of a repeated Prisoner's Dilemma played by individuals who may exhibit a different memory capacity. Here, memory is greatly simplified and mapped onto a single parameter m describing the number of conspecifics whose previous action each individual can remember. We show that increasing m enables cooperation to emerge and be maintained in groups of increasing sizes. Furthermore, harsher social dilemmas lead to the need for a higher m in order to ensure high levels of cooperation. Finally, we show how the interplay between the dilemma individuals face and their memory capacity m allows us to define a critical group size below which cooperation may thrive, and how this value depends sensitively on the strength of natural selection.

Individual memory and the emergence of cooperation
João Moreira, Jeromos Vukov, Cláudia Sousa, Francisco C. Santos, André F. d'Almeida, Marta D. Santos, Jorge M. Pacheco
Animal Behaviour
Available online 4 December 2012
In Press, Corrected Proof
http://dx.doi.org/10.1016/j.anbehav.2012.10.030Descripción: http://www.scoop.it/rv?p=3716586824&tp=Topic





miércoles, 12 de septiembre de 2012


A Creation Story for Humanity
Edward O. Wilson is not afraid to ask big questions—questions that religions, the creative arts, and philosophy have wrestled with for centuries. What is it that makes humans what they are? How did our human condition develop? How did nature give rise to something so unusual as ourselves—a species that feels empathy and guilt, cares for the old and sick, and tries to intellectually understand itself and its origins—with our languages, religions, arts, and cultures? With The Social Conquest of Earth, Wilson endeavors to uncover the creation story of humanity. (...) Wilson suggests visualizing the evolution of a species as a journey through a maze presented by the environment, a maze that can itself change with time. (...) Wilson argues that a multilevel selection perspective offers the best approach to understanding the human condition.

A Creation Story for Humanity
Rudolf Griss
Science 31 August 2012:
Vol. 337 no. 6098 p. 1041
http://dx.doi.org/10.1126/science.1225640


On the evolutionary origins of the egalitarian syndrome
The evolutionary emergence of the egalitarian syndrome is one of the most intriguing unsolved puzzles related to the origins of modern humans. Standard explanations and models for cooperation and altruism—reciprocity, kin and group selection, and punishment—are not directly applicable to the emergence of egalitarian behavior in hierarchically organized groups that characterized the social life of our ancestors. Here I study an evolutionary model of group-living individuals competing for resources and reproductive success. In the model, the differences in fighting abilities lead to the emergence of hierarchies where stronger individuals take away resources from weaker individuals and, as a result, have higher reproductive success. (...)

On the evolutionary origins of the egalitarian syndrome
Sergey Gavrilets


The automatic chemist
Bartosz Grzybowski of Northwestern University in Illinois, US – who has already established himself as one of our most inventive chemists – has unveiled a ‘chemo-informatic’ scheme, Chematica, that can stake a reasonable claim to being paradigm-changing. Grzybowski and his colleagues have spent years assembling the transformations that link chemical species into a vast network that codifies and organises the known pathways through chemical space. The nodes of the network – molecules, elements and chemical reactions – are linked together by connecting reactants to products via the nexus of a known reaction. The full network contains around 7 million compound nodes and about the same number of reaction nodes. Grzybowski calls it a ‘collective chemical brain’.

The automatic chemist
Philip Ball
Chemistry World 22 August 2012


Criticality Is an Emergent Property of Genetic Networks that Exhibit Evolvability
Dynamically critical systems are those which operate at the border of a phase transition between two behavioral regimes often present in complex systems: order and disorder. Critical systems exhibit remarkable properties such as fast information processing, collective response to perturbations or the ability to integrate a wide range of external stimuli without saturation. Recent evidence indicates that the genetic networks of living cells are dynamically critical. This has far reaching consequences, for it is at criticality that living organisms can tolerate a wide range of external fluctuations without changing the functionality of their phenotypes. Therefore, it is necessary to know how genetic criticality emerged through evolution. Here we show that dynamical criticality naturally emerges from the delicate balance between two fundamental forces of natural selection that make organisms evolve: (i) the existing phenotypes must be resilient to random mutations, and (ii) new phenotypes must emerge for the organisms to adapt to new environmental challenges. The joint effect of these two forces, which are essential for evolvability, is sufficient in our computational models to generate populations of genetic networks operating at criticality. Thus, natural selection acting as a tinkerer of evolvable systems naturally generates critical dynamics.

Criticality Is an Emergent Property of Genetic Networks that Exhibit Evolvability
Christian Torres-Sosa, Sui Huang, Maximino Aldana
PLoS Comput Biol 8(9): e1002669. http://dx.doi.org/10.1371/journal.pcbi.1002669

Predatory Fish Select for Coordinated Collective Motion in Virtual Prey
Movement in animal groups is highly varied and ranges from seemingly disordered motion in swarms to coordinated aligned motion in flocks and schools. These social interactions are often thought to reduce risk from predators, despite a lack of direct evidence. We investigated risk-related selection for collective motion by allowing real predators (bluegill sunfish) to hunt mobile virtual prey. By fusing simulated and real animal behavior, we isolated predator effects while controlling for confounding factors. Prey with a tendency to be attracted toward, and to align direction of travel with, near neighbors tended to form mobile coordinated groups and were rarely attacked. These results demonstrate that collective motion could evolve as a response to predation, without prey being able to detect and respond to predators.

Predatory Fish Select for Coordinated Collective Motion in Virtual Prey
C. C. Ioannou, V. Guttal, I. D. Couzin
Science 7 September 2012:
Vol. 337 no. 6099 pp. 1212-1215
http://dx.doi.org/10.1126/science.1218919

ENCODE Project Writes Eulogy for Junk DNA
This week, 30 research papers, including six in Nature and additional papers published online by Science, sound the death knell for the idea that our DNA is mostly littered with useless bases. A decade-long project, the Encyclopedia of DNA Elements (ENCODE), has found that 80% of the human genome serves some purpose, biochemically speaking. Beyond defining proteins, the DNA bases highlighted by ENCODE specify landing spots for proteins that influence gene activity, strands of RNA with myriad roles, or simply places where chemical modifications serve to silence stretches of our chromosomes.

ENCODE Project Writes Eulogy for Junk DNA
Elizabeth Pennisi
Science 7 September 2012:
Vol. 337 no. 6099 pp. 1159-1161
http://dx.doi.org/10.1126/science.337.6099.1159


How Culture Drove Human Evolution
The main questions I've been asking myself over the last couple years are broadly about how culture drove human evolution. Think back to when humans first got the capacity for cumulative cultural evolution—and by this I mean the ability for ideas to accumulate over generations, to get an increasingly complex tool starting from something simple. One generation adds a few things to it, the next generation adds a few more things, and the next generation, until it's so complex that no one in the first generation could have invented it. This was a really important line in human evolution, and we've begun to pursue this idea called the cultural brain hypothesis—this is the idea that the real driver in the expansion of human brains was this growing cumulative body of cultural information, so that what our brains increasingly got good at was the ability to acquire information, store, process and retransmit this non genetic body of information.
Descripción: http://www.scoop.it/rv?p=2590829309&tp=Topic



sábado, 18 de agosto de 2012

Osvaldo Reig


INFATIGABLE. OSVALDO REIG.

Por Ignacio Soto,
Laboratorio de Evolución, DEGE, FCEN, UBA


Nota publicada originalmente en la revista ADN (http://www.revista-adn.com.ar)


Perfil de Osvaldo Reig, uno de los más grandes biólogos evolutivos de nuestro país que supo combinar compromiso político, crítica científica y excelencia académica.
Pasados 20 años desde su fallecimiento, hay generaciones de biólogos y paleontólogos que se formaron sin conocerlo, pero su legado académico y humano se reconoce en multitud de ámbitos apenas se comienza a indagar sobre él. ¿Quién fue ese mentor que enorgullece a sus discípulos y que no dudó en cambiar de disciplina científica en el momento que sintió que su curiosidad no estaba siendo satisfecha? 




“Por más que sea gratificante alcanzar un deseable reconocimiento internacional, la verdadera satisfacción del científico con su quehacer profesional surgirá cuando su propio país le proporcione legitimidad y arraigo”  
O.A. Reig, 1992.

Los biólogos de mi generación no conocimos personalmente a Osvaldo Reig. Para aquellos que comenzamos a cursar en la Facultad de Ciencias Exactas a finales de la década del 90, Reig es un nombre en una placa de un aula. En ese sentido, tan etéreo e inasible como “Amos”, “Leloir” o “Burkart” por nombrar otros apellidos que custodian lugares de esta Facultad. Entonces, escribir sobre Osvaldo no responde, en mi caso, a una admiración desarrollada por interacción con su persona en vida o a querer preservar en escrito vivencias personales que lo incluyen. Probablemente sea más bien una indagación sobre quien fue ese científico cuya ausencia tiene tanto de reciente que genera esa incómoda idea de que fue solo por poco que uno se perdió de conocer. Si hoy rescatamos este nombre de una placa es porque tiene una vigencia innegable y es una cantera formidable de conocimiento y principios para aprovechar, pero por sobre todo, por ser un ejemplo de superación de dificultades. Una persona que siendo reconocida mundialmente buscaba la legitimidad y el arraigo en su país.
Aquellos que se adentran en el estudio de la zoología, paleontología o biología evolutiva, tarde o temprano llegan a su obra. Su pensamiento enseguida rodea y acompaña a aquellos que indagan sobre el desarrollo de la biología y paleontología argentina del siglo XX.
Los aportes científicos de Reig comenzaron muy tempranamente en su vida. La biblioteca familiar tenía obras de Darwin y de Ameghino que Osvaldo no tardó en apreciar. De adolescente fue un aficionado autodidacta de la Paleontología. En 1945, iba a publicar junto con su amigo Jorge Kraglievich y con tan solo 16 años su primer trabajo científico, una descripción de un carpincho fósil, en las Notas del Museo de la Plata. Por la misma época era expulsado del Colegio Nacional Buenos Aires por sus cuestionamientos al autoritarismo del gobierno local y el fascismo europeo. Esta dinámica entre logros científicos y avatares políticos será una constante que lo acompañará por el resto de sus días.
Reig comenzó los estudios universitarios en 1950 en la Universidad de La Plata, pero no pudo completarlos allí. Su militancia progresista le había significado maltratos, persecuciones, cárcel y torturas. A los dos años se estaba yendo a Buenos Aires a trabajar en el Museo Argentino Bernardino Rivadavia y retomar brevemente sus estudios, ahora en la Universidad de Buenos Aires.
Su crecimiento profesional continuará firme. En 1955 reporta un descubrimiento de gran relevancia. Analizando la morfología dentaria y otras características esqueletarias concluye que el marsupial conocido como Monito del Monte (Dromiciops australis), habitante de nuestros bosques patagónicos, pertenecía al grupo de los microbiotéridos, descriptos por Florentino Ameghino y considerado un grupo de mamíferos marsupiales extintos hacía millones de años. La Argentina tenía su propio fósil viviente. Por otro lado, sus estudios sobre anuros fósiles del género Nothobatrachus, de los más antiguos conocidos en ese momento, le brinda un mayor prestigio internacional. En 1957 es electo Presidente de la Asociación Paleontológica Argentina. Esta consolidación de su reputación como paleontólogo, lejos de anquilosarlo, lo lleva a ampliar sus investigaciones. Es un convencido de que el estudio de los fósiles es incompleto si no incluye un marco más amplio brindado por la biología evolutiva. Cuando en 1959 discute en Holmbergia si la Paleontología pertenece al campo de la Biología o de la Geología (él era un acérrimo defensor de lo primero) se encarga de aclarar que no es una discusión meramente formal. Entendía que era un problema que debía encararse ya que “de la adecuada resolución de este litigio de pertenencia depende la médula racional, el fundamento conceptual necesario para un adecuado planteo de los objetivos del trabajo del investigador interesado por los organismos del pasado.” Años más tarde definiría como enriquecedor y gratificante el “salto” de la Paleontología hacia la Genética Evolutiva aunque lo percibió más bien como una integración de enfoques: “exigida por la propia dinámica de la maduración de mi indagación sobre los procesos evolutivos
El otro aspecto relevante para apreciar la obra de Reig es su faceta de fundador de grupos de investigación. En 1958, con un cargo de Profesor en la Universidad de Tucumán funda, en el Instituto Fundación Miguel Lillo, el Laboratorio de Vertebrados Fósiles y en paralelo uno de herpetología. Organiza con Galileo Scaglia expediciones a Ischigualasto, San Juan, con la colaboración de varios paleontólogos del país entre los que se encontraba José Bonaparte que luego continuará con esa labor. Estas expediciones ponen al Valle de la Luna en el mapa de la paleontología mundial aportando valiosos datos sobre la fase temprana de la evolución de los dinosaurios y preservando muchos especímenes de campañas norteamericanas a la misma zona que sacaban del país a los fósiles encontrados.
En 1960 es contratado por la Universidad de Buenos Aires y vuelve a la Facultad de Ciencias Exactas como Profesor. Su trabajo en la FCEyN, en el Departamento de Ciencias Biológicas, se centrará en estudios evolutivos de los mamíferos sudamericanos. En 1961 gana por concurso un cargo de Profesor Titular a pesar de no contar con un título de grado y gracias a sus evidentes méritos científicos (el famoso paleontólogo George Gaylord Simpson formaba parte del jurado). En 1962 funda el LIHUBA, Laboratorio de Investigaciones Herpetológicas de la Universidad de Buenos Aires, y en 1963 comienza a coordinar el grupo de Biología Evolutiva de Vertebrados en el Departamento de Ciencias Biológicas. La Genética y Ecología de Poblaciones comienzan a ser el campo central de sus investigaciones.  
No estuvo ajeno a una de las etapas más tristes de la historia de la ciencia argentina. Mientras se encontraba en una estadía de investigación en Harvard, en nuestro país se desataba el golpe del 66 y la Noche de los Bastones Largos. Osvaldo Reig renuncia a su cargo de profesor y deja todo su equipo atrás para exiliarse en Venezuela. En la Universidad Central de Venezuela organizará el Grupo de Evolución y Citogenética. También comenzara estudios en Chile donde organizará y, de 1972 a 1973, será el director del Instituto de Genética y Evolución de la Facultad de Ciencias de la Universidad Austral. Allí estudiaba a los ratones de campo y los tuco-tucos.
Osvaldo se doctoró en 1973 en Londres (Área de Zoología y Paleontología, Facultad de Ciencias, University College of London) sin haber terminado una licenciatura en su país natal.
Al regresar a Chile otra vez la política atentará contra su trabajo. El presidente Allende es derrocado en un golpe militar. El perfil de Reig, su militancia, lo pone en la mira del nuevo gobierno. Es secuestrado y encarcelado y su vida realmente corre peligro. Solo la presión y gestión internacional permite su liberación. Vuelve a la Argentina y a la UBA con un cargo en la FCEyN pero nuestro país no es ajeno a la turbulencia política y Osvaldo sentirá el hostigamiento también aquí. Estando en un congreso en México se entera de que el rector interventor Ottalagano lo había echado de la UBA. Ni siquiera regresa a Buenos Aires y vuela directamente a Venezuela, donde es cordialmente recibido por sus colegas pero se enfrenta a un nuevo exilio. Primero en la Universidad de Los Andes en Mérida y luego en la Universidad Simón Bolívar de Caracas, Reig continuará con sus líneas de investigación. Sus estudios en roedores y marsupiales sobre especiación y su correlato con la evolución cromosómica cobran un gran desarrollo. Es uno de los científicos que acompaña los replanteos a algunos postulados básicos de la Síntesis Moderna. Su amistad con Mario Bunge y la enriquecedora influencia de la filósofa Estela Santilli, su mujer y compañera en la vida itinerante, hicieron que siempre fueran muy fuertes sus inquietudes epistemológicas. En uno de sus escritos podemos leer de su propio puño: “Las preocupaciones epistemológicas, los intentos de clasificación de las ciencias, deben valorarse como temas cuyo desarrollo es altamente beneficioso y necesario para el desenvolvimiento de las investigaciones; para encontrar sentido y objetivos a las tareas del científico que, desvinculadas de los intentos interpretativos y de la correcta delimitación de metas, pueden perder jerarquía y desvanecerse en el juego fácil de lo rutinario, en las autosuficiencias de lo meramente analítico y clasificatorio.”
Así Reig suma a su quehacer paleontológico y genético la reflexión sobre los enfoques reduccionistas en la biología evolutiva y sobre la realidad de las especies biológicas. Asimismo, empieza a considerar a la variabilidad que se encuentra entre los individuos de una misma especie como un tópico central para la comprensión de los fenómenos evolutivos. Sus resultados iban a ser discutidos con los de las grandes figuras de la biología evolutiva de esas décadas.
Por esos tiempos entiende que necesita incorporar otro modelo más para terminar de complementar sus líneas de investigación. Así el paleontólogo/mastozoólogo/herpetólogo incorpora a las moscas del género Drosophila como modelo genético evolutivo de sus investigaciones. Por sus características biológicas, estos insectos le permitían la experimentación y puesta a prueba de hipótesis sobre especiación y evolución como ningún otro de sus objetos de estudio. Pero incluso con este modelo clásico tendrá una vuelta de tuerca. Las especies de Drosophila que comienza a estudiar son un grupo particular de moscas neotropicales especializadas en la explotación de los cactus como medio de cría. En otras palabras, un modelo genético clásico e internacional pero aggiornado a problemáticas y eventos biológicos con interés regional.
Volverá a nuestro país en 1983, luego del restablecimiento del orden democrático, como miembro superior del Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Originalmente regresa con un proyecto para hacerse cargo,  reorganizar y modernizar el Museo Argentino de Ciencias Naturales. Si bien cuenta con el apoyo de las autoridades nacionales, algunos sectores conservadores y de la Iglesia Católica montan una campaña mediática (algunos recuerdan a Magdalena Ruiz Guiñazu arengando indignada desde su programa de radio) para que Reig no se instale en el Museo. Finalmente estos sectores se impondrán y otro proyecto de Reig quedará trunco.
La consolidación de tiempos democráticos no significa el cese de la hostilidad por parte de otros colegas. Se instalará finalmente en la facultad de Ciencias Exactas y Naturales de la UBA, donde organiza el Grupo de Investigación en Biología Evolutiva (GIBE) para continuar con sus investigaciones en genética y ecología evolutiva. Los estudios incluirán sus diversos modelos animales, desde tuco-tucos y primates neotropicales hasta las moscas del género Drosophila. Aquí también, quizás por representar vientos de cambio, tendrá que confrontar y sufrir la interacción con los resabios académicos que sobrevivieron los años oscuros del Proceso.   
1986 resulta un año que delinea de manera muy interesante lo que fue parte de su vida. En un mundo bipolar, ordenado por las tensiones de la Guerra Fría, se puede decir que todos los bloques involuntariamente consensuan reconocer la carrera de Reig de manera simultánea. La Academia de Ciencias de la Unión Soviética lo nombra Miembro Honorario mientras que la Academia Nacional de Ciencias de Estados Unidos lo acepta como Miembro Asociado Extranjero. Como si fuera poco, la Academia de Ciencias del Tercer Mundo también lo nombrará miembro. Triple reconocimiento en un mundo dividido.
La cosecha de reconocimientos continuará. En 1989 la Universidad Autónoma de Barcelona le otorga el título de Doctor Honoris Causa y la Universidad de Buenos Aires lo hará en 1991. Un año después la Universidad Simón Bolívar lo nombrará Profesor Honorario.
Algunos pasajes de su discurso de aceptación del título en la Universidad de Barcelona son fieles resúmenes de cuáles fueron sus motivaciones y principios durante su carrera científica:

Ahora está claro que la comprensión de los procesos evolutivos presupone la ampliación permanente del contexto teórico y el trabajo multidisciplinario y en equipo. Eso exige deponer la adhesión a cotos de investigación excluyentes. (…) Habrá siempre quienes se resientan a abandonar los privilegios que presupone practicar una disciplina que pretende ser autosuficiente. Siempre existirán los que traten de explicar mucho con lo poco que saben. El verdadero científico será siempre, empero, aquel que reconoce los límites de su saber, y que sabe convocar el conocimiento ajeno. (…) No hay nada más distante de los enunciados de la ciencia que las afirmaciones apodícticas de certeza, ni nada más contradictorio con la actitud científica que el fundamentalismo y el infabilismo.”

Osvaldo Reig fue un biólogo evolutivo que hizo ciencia de calidad en los contextos más adversos que podemos imaginar. Exiliado y perseguido, su éxodo dejó un semillero de laboratorios y grupos de trabajo en la Patria Grande. Las condiciones políticas lo expulsaron dos veces de nuestra Facultad pero terminó establecido en ella, trabajando a la vanguardia de la biología evolutiva. Su legado está en todos lados.
Hoy, a más de 20 años de planteadas, los laboratorios del GIBE y de Evolución en el Departamento de Ecología, Genética y Evolución continúan respondiendo, desarrollando y ampliando las preguntas de Osvaldo sobre especiación, genética y ecología evolutiva. Osvaldo Reig estableció el dictado de Evolución, Macroevolución y, junto a la Dra Ana Báez, Sistemática Teórica en la carrera de Biología. Siempre consideró que Evolución debía ser una materia básica de la carrera. Algunos de sus becarios y tesistas son ahora investigadores y profesores de esta Facultad y sus ex alumnos son aún más numerosos. Para muestra basta un botón. El Dr. Hernán Dopazo volvió al país el año pasado y ahora dirige el Laboratorio de Genómica Biomédica y Evolución en el Departamento de Ecología, Genética y Evolución. Hernán hizo su tesina de licenciatura en el GIBE de Reig y fue ayudante en sus materias. Consultado sobre sus experiencias directas con su mentor rescata el privilegio que le significó las charlas que entablaban de regreso a sus hogares después de dar clase. Lo considera un maestro porque generaba y transmitía rigor de pensamiento en quienes formó. “Era un gigante”- explica Hernán- “No volví a encontrar una persona así en todos los años de carrera que hice”.                                                                                                                                                                          
Nunca se quedó quieto, nunca se “acomodó” en un tema. No hizo la plancha. No se conformó. Hace 20 años moría Osvaldo Reig.  Este 14 de agosto hubiera cumplido 83 años. Nos deja mucho más que Ischigualasto, el Monito del Monte como fósil viviente, Nothobatrachus, dinosaurios, la biología evolutiva argentina hermanada a su paleontología, ideas sobre el origen de las especies, reflexiones sobre el cómo hacer ciencia y como no hacerla, sobre el despotismo y el abuso del poder, líneas de investigación, decenas de investigadores formados y un ejemplo de compromiso real con las convicciones personales. Sus campos fueron la paleontología, la biología evolutiva, la genética, la sistemática y la biogeografía. Pero con una producción académica de excelencia sus aportes más valiosos quizás no se puedan buscar en papers. El autodenominado “biólogo itinerante” nos dejó una hoja de ruta formidable. Admirador de Ameghino y trabajador incansable, trasmitió la importancia del rigor en cada aspecto de la construcción del conocimiento.
A veces las placas guardan nombres ilustres que trasmiten solemnidad y respeto. A veces no mucho más que eso. Pero cada tanto, el bronce atrapa aunque sea el nombre de gente infatigable, buscadores de verdades, de fósiles, ratones o moscas. Esa gente que años más tarde, a quienes no lo conocimos, todavía nos da la sensación de que nos lo perdimos por poco.

Agradecimientos:
Quiero agradecer al Dr Hernán Dopazo y al Dr. Esteban Hasson por facilitarme experiencias y anécdotas y al Dr. Raúl Gómez por las contribuciones bibliográficas.

Bibliografía consultada (y recomendada para profundizar el tema):
Quintana C.A. 2012. Conociendo a nuestros científicos. Osvaldo Alfredo Reig. Pp 42. Ediciones ULP, Argentina.
Reig, OA. 1959. Acerca de la ubicación de los estudios paleontológicos. Holmbergia 15(4):19-45
Reig, OA. 1989. Doctor Honoris Causa. Discurso leído en la ceremonia de investidura. Facultad de Ciencias, Universidad de Barcelona. Bellaterra.



Surprising finding: Tree's leaves genetically different from its roots


Black cottonwood trees (Populus trichocarpa) can clone themselves to produce offspring that are connected to their parents by the same root system. Now, after the first genome-wide analysis of a tree, it turns out that the connected clones have many genetic differences, even between tissues from the top and bottom of a single tree. The variation within a tree is as great as the variation across unrelated trees. Such somatic mutations — those that occur in cells other than sperm or eggs — are familiar to horticulturalists, who have long bred new plant varieties by grafting mutant branches onto ‘normal’ stocks. But until now, no one has catalogued the total number of somatic mutations in an individual plant.

In one tree, the top buds of the parent and offspring were genetically closer to each other than to their respective roots or lower branches. In another tree, the top bud was closer to the reference cottonwood genome than to any of the other tissues from the same individual.The tissue-specific mutations affected mainly genes involved in cell death, immune responses, metabolism, DNA binding and cell communication. Olds think that this may be because many of the mutations are harmful, and the tree reacts by destroying the mutated tissues or altering its metabolic pathways and the way it controls its genes, which leads to further mutations.

The findings have parallels to cancer studies, which have recently shown that separate parts of the same tumor can evolve independently and build up distinct genetic mutations, meaning that single biopsies give only a narrow view of the tumor’s diversity.


Human cycles: History as science



For the past 15 years, Turchin has been taking the mathematical techniques that once allowed him to track predator–prey cycles in forest ecosystems, and applying them to human history. He has analysed historical records on economic activity, demographic trends and outbursts of violence in the United States, and has come to the conclusion that a new wave of internal strife is already on its way1. The peak should occur in about 2020, he says, and will probably be at least as high as the one in around 1970. “I hope it won't be as bad as 1870,” he adds.

Human cycles: History as science
Laura Spinney
Nature 488, 24–26 (02 August 2012) http://dx.doi.org/10.1038/488024a


Inescapable Pull
Black holes, once the preserve of theory and science fiction, are well-established inhabitants of the universe. Observations of the motions of stars orbiting the center of the Milky Way have proved beyond doubt that a black hole 4 million times as massive as the Sun resides there. Many other galaxies are thought to host similarly heavy or even heavier black holes at their centers. Scattered out beyond the center, there are thought to be millions of lighter, stellar-mass black holes, produced when the most massive stars collapse in on themselves at the end of their lives. This week, Science explores the current state of understanding of black holes with a series of Perspectives and Reviews.

Inescapable Pull
Maria Cruz
Science 3 August 2012:
Vol. 337 no. 6094 p. 535
http://dx.doi.org/10.1126/science.337.6094.535


Measuring the Complexity of Ultra-Large-Scale Evolutionary Systems
Ultra-large scale (ULS) systems are becoming pervasive. They are inherently complex, which makes their design and control a challenge for traditional methods. Here we propose the design and analysis of ULS systems using measures of complexity, emergence, self-organization, and homeostasis based on information theory. We evaluate the proposal with a ULS computing system provided with genetic adaptation mechanisms. We show the evolution of the system with stable and also changing workload, using different fitness functions. When the adaptive plan forces the system to converge to a predefined performance level, the nodes may result in highly unstable configurations, that correspond to a high variance in time of the measured complexity. Conversely, if the adaptive plan is less "aggressive", the system may be more stable, but the optimal performance may not be achieved.

Measuring the Complexity of Ultra-Large-Scale Evolutionary Systems
Michele Amoretti, Carlos Gershenson


Some Computational Aspects of Essential Properties of Evolution and Life
While evolution has inspired algorithmic methods of heuristic optimisation, little has been done in the way of using concepts of computation to advance our understanding of salient aspects of biological phenomena. We argue that under reasonable assumptions, interesting conclusions can be drawn that are of relevance to behavioural evolution. We will focus on two important features of life--robustness and fitness--which, we will argue, are related to algorithmic probability and to the thermodynamics of computation, disciplines that may be capable of modelling key features of living organisms, and which can be used in formulating new algorithms of evolutionary computation.

Some Computational Aspects of Essential Properties of Evolution and Life
Hector Zenil, James A.R. Marshall


Why We Lie
 

Over the past decade or so, my colleagues and I have taken a close look at why people cheat, using a variety of experiments and looking at a panoply of unique data sets—from insurance claims to employment histories to the treatment records of doctors and dentists. What we have found, in a nutshell: Everybody has the capacity to be dishonest, and almost everybody cheats—just by a little. Except for a few outliers at the top and bottom, the behavior of almost everyone is driven by two opposing motivations. On the one hand, we want to benefit from cheating and get as much money and glory as possible; on the other hand, we want to view ourselves as honest, honorable people. Sadly, it is this kind of small-scale mass cheating, not the high-profile cases, that is most corrosive to society.

Introducing the Computable Universe
Some contemporary views of the universe assume information and computation to be key in understanding and explaining the basic structure underpinning physical reality. We introduce the Computable Universe exploring some of the basic arguments giving foundation to these visions. We will focus on the algorithmic and quantum aspects, and how these may fit and support the computable universe hypothesis.

Introducing the Computable Universe
Hector Zenil