Compilado AZyNE 28-12

To Group or Not to Group?, Science

Summary: The phenomenon of cooperation between potentially competing individuals raises an interesting question related to evolution: Why should a competitor favor someone else's fitness at the expense of its own? One way to approach this question is through insights on how cooperation and population structure coevolve.

• Source: To Group or Not to Group?, Eörs Szathmáry, DOI: 10.1126/science.1209548, Science Vol. 334 no. 6063 pp. 1648-1649, 2011/12/23

Antonio Damasio: The quest to understand consciousness, TED.com

About this talk: Every morning we wake up and regain consciousness -- that is a marvelous fact -- but what exactly is it that we regain? Neuroscientist Antonio Damasio uses this simple question to give us a glimpse into how our brains create our sense of self.

• Source: Antonio Damasio: The quest to understand consciousness, TED.com, 2011/12
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Evolution and development of Brain Networks: From Caenorhabditis elegans to Homo sapiens, arXiv

Abstract: Neural networks show a progressive increase in complexity during the time course of evolution. From diffuse nerve nets in Cnidaria to modular, hierarchical systems in macaque and humans, there is a gradual shift from simple processes involving a limited amount of tasks and modalities to complex functional and behavioral processing integrating different kinds of information from highly specialized tissue. However, studies in a range of species suggest that fundamental similarities, in spatial and topological features as well as in developmental mechanisms for network formation, are retained across evolution. 'Small-world' topology and highly connected regions (hubs) are prevalent across the evolutionary scale, ensuring efficient processing and resilience to internal (e.g. lesions) and external (e.g. environment) changes. Furthermore, in most species, even the establishment of hubs, long-range connections linking distant components, and a modular organization, relies on similar mechanisms. In conclusion, evolutionary divergence leads to greater complexity while following essential developmental constraints.

• Source: Evolution and development of Brain Networks: From Caenorhabditis elegans to Homo sapiens, Marcus Kaiser and Sreedevi Varier, arXiv:1112.5449, 2011/12/22

The Diversity Paradox: How Nature Resolves an Evolutionary Dilemma, arXiv

Excerpt: Adaptation to changing environments is a hallmark of biological systems. Diversity in traits is necessary for adaptation and can influence the survival of a population faced with novelty. In habitats that remain stable over many generations, stabilizing selection reduces trait differences within populations, thereby appearing to remove the diversity needed for heritable adaptive responses in new environments. Paradoxically, field studies have documented numerous populations under long periods of stabilizing selection and evolutionary stasis that have rapidly evolved under changed environmental conditions. In this article, we review how cryptic genetic variation (CGV) resolves this diversity paradox by allowing populations in a stable environment to gradually accumulate hidden genetic diversity that is revealed as trait differences when environments change. (…)

• Source: The Diversity Paradox: How Nature Resolves an Evolutionary Dilemma, James M. Whitacre and Sergei P. Atamas, arXiv:1112.3115, 2011/12/14

Facing Complexity: Prediction vs. Adaptation, arXiv

Abstract: One of the presuppositions of science since the times of Galileo, Newton, Laplace, and Descartes has been the predictability of the world. This idea has strongly influenced scientific and technological models. However, in recent decades, chaos and complexity have shown that not every phenomenon is predictable, even if it is deterministic. If a problem space is predictable, in theory we can find a solution via optimization. Nevertheless, if a problem space is not predictable, or it changes too fast, very probably optimization will offer obsolete solutions. This occurs often when the immediate solution affects the problem itself. An alternative is found in adaptation. An adaptive system will be able to find by itself new solutions for unforeseen situations.

• Source: Facing Complexity: Prediction vs. Adaptation, Carlos Gershenson, arXiv:1112.3843, 2011/12/16

Compilado AZyNE 12-12

Cheryl Hayashi: The magnificence of spider silk, TED.com

About this talk: Cheryl Hayashi studies spider silk, one of nature's most high-performance materials. Each species of spider can make up to 7 very different kinds of silk. How do they do it? Hayashi explains at the DNA level -- then shows us how this super-strong, super-flexible material can inspire.

• Source: Cheryl Hayashi: The magnificence of spider silk, TED.com, 2011/12
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Impact of epistasis and pleiotropy on evolutionary adaptation, Proc. R. Soc. B

Excerpt: Evolutionary adaptation is often likened to climbing a hill or peak. While this process is simple for fitness landscapes where mutations are independent, the interaction between mutations (epistasis) as well as mutations at loci that affect more than one trait (pleiotropy) are crucial in complex and realistic fitness landscapes.

• Source: Impact of epistasis and pleiotropy on evolutionary adaptation, Østman B, Hintze A, Adami C, DOI: 10.1098/rspb.2011.0870, Proc. R. Soc. B vol. 279 no. 1727: 247-256, December 2011

Energetics and the evolution of human brain size, Nature

Excerpt: The human brain stands out among mammals by being unusually large. The expensive-tissue hypothesis1 explains its evolution by proposing a trade-off between the size of the brain and that of the digestive tract, which is smaller than expected for a primate of our body size. Although this hypothesis is widely accepted, empirical support so far has been equivocal. Here we test it in a sample of 100 mammalian species, including 23 primates, by analysing brain size and organ mass data. We found that, controlling for fat-free body mass, brain size is not negatively correlated with the mass of the digestive tract or any other expensive organ, thus refuting the expensive-tissue hypothesis.

• Source: Energetics and the evolution of human brain size, Ana Navarrete, Carel P. van Schaik & Karin Isler, DOI: 10.1038/nature10629, Nature 480, 91�"93, 2011/12/01

Compilado AZyNE 25-11

Lynn Margulis 1938-2011 "Gaia Is A Tough Bitch", Edge.org

Excerpt: Biologist Lynn Margulis died on November 22nd. She stood out from her colleagues in that she would have extended evolutionary studies nearly four billion years back in time. Her major work was in cell evolution, in which the great event was the appearance of the eukaryotic, or nucleated, cell �" the cell upon which all larger life-forms are based. Nearly forty-five years ago, she argued for its symbiotic origin: that it arose by associations of different kinds of bacteria. Her ideas were generally either ignored or ridiculed when she first proposed them; symbiosis in cell evolution is now considered one of the great scientific breakthroughs.

• Source: Lynn Margulis 1938-2011 "Gaia Is A Tough Bitch", John Brockman, Edge.org, 2011/11/23

The role of sex separation in neutral speciation, arXiv

Abstract: Neutral speciation mechanisms based on isolation by distance and sexual selection, termed topopatric, have recently been shown to describe the observed patterns of abundance distributions and species-area relationships. Previous works have considered this type of process only in the context of hermaphrodic populations. In this work we extend a hermaphroditic model of topopatric speciation to populations where individuals are explicitly separated into males and females. We show that for a particular carrying capacity speciation occurs under similar conditions, but the number of species generated decreases as compared to the hermaphroditic case. Evolution results in fewer species having more abundant populations.

• Source: The role of sex separation in neutral speciation, Elizabeth M. Baptestini, Marcus A.M. de Aguiar, Yaneer Bar-Yam, arXiv:1111.4643, 2011/11/20

Evolutionary Time Travel, Science

Summary: With clever and challenging lab experiments, researchers are forcing species to become multicellular, develop new energy sources, and start having sex.

• Source: Evolutionary Time Travel, Elizabeth Pennisi, DOI: 10.1126/science.334.6058.893, Science Vol. 334 no. 6058 pp. 893-895, 2011/11/18

Compilado AZyNE 12-11

Social Network Size Affects Neural Circuits in Macaques, Science

Abstract: It has been suggested that variation in brain structure correlates with the sizes of individuals’ social networks. Whether variation in social network size causes variation in brain structure, however, is unknown. To address this question, we neuroimaged 23 monkeys that had been living in social groups set to different sizes. Subject comparison revealed that living in larger groups caused increases in gray matter in mid-superior temporal sulcus and rostral prefrontal cortex and increased coupling of activity in frontal and temporal cortex. Social network size, therefore, contributes to changes both in brain structure and function. The changes have potential implications for an animal’s success in a social context; gray matter differences in similar areas were also correlated with each animal’s dominance within its social network.

• Source: Social Network Size Affects Neural Circuits in Macaques, J. Sallet, DOI: 10.1126/science.1210027, Science Vol. 334 no. 6056 pp. 697-700, 2011/11/4

Evolutionary biology: The path to sociality, Nature

Excerpt: (…) some hints about the sequence of events that led to the evolution of human social systems are emerging. The latest evidence comes from Shultz et al.1, who (…) trace the evolution of complex sociality within the order Primates. Their data provide a strong foundation for modelling the origins of hominid mating systems by constraining the range of likely trajectories of social change.

• Source: Evolutionary biology: The path to sociality, Joan B. Silk, DOI: 10.1038/479182a, Nature 479, 182�"183, 2011/11/9

Stepwise evolution of stable sociality in primates, Nature

Excerpt: (…) This supports suggestions that social living may arise because of increased predation risk associated with diurnal activity. Sociality based on loose aggregation is followed by a second shift to stable or bonded groups. This structuring facilitates the evolution of cooperative behaviours5 and may provide the scaffold for other distinctive anthropoid traits including coalition formation, cooperative resource defence and large brains.

• Source: Stepwise evolution of stable sociality in primates, Susanne Shultz, Christopher Opie & Quentin D. Atkinson, DOI: 10.1038/nature10601, Nature 479, 219�"222, 2011/11/9

Martin Hanczyc: The line between life and not-life, TED.com

About this talk: In his lab, Martin Hanczyc makes "protocells," experimental blobs of chemicals that behave like living cells. His work demonstrates how life might have first occurred on Earth ... and perhaps elsewhere too.

• Source: Martin Hanczyc: The line between life and not-life, TED.com, 2011/11
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Daniel Wolpert: The real reason for brains, TED.com

About this talk: Neuroscientist Daniel Wolpert starts from a surprising premise: the brain evolved, not to think or feel, but to control movement. In this entertaining, data-rich talk he gives us a glimpse into how the brain creates the grace and agility of human motion.

• Source: Daniel Wolpert: The real reason for brains, TED.com, 2011/11

Mathematics: Alice in time, Nature

Excerpt: Time haunts both Alice books. Lewis Carroll, author of Alice's Adventures in Wonderland (1865) and Through the Looking-Glass (1871), was also Charles Dodgson, mathematician and logician, and so was aware of the disturbing arguments, new in the mid-nineteenth century, that suggested our view of the geometry of space and time was not universal.
As Dodgson, he was a devout Euclidean, believing that planes are flat and parallel lines never meet. As Lewis Carroll, he stepped across those boundaries.

• Source: Mathematics: Alice in time, Gillian Beer, DOI: 10.1038/479038a, Nature 479, 38�"39, 2011/11/2

Mental problems gave early humans an edge - life - 07 November 2011 - New Scientist

Mental problems gave early humans an edge - life - 07 November 2011 - New Scientist

Compilado AZyNE 31-10

Dynamical modeling of collective behavior from pigeon flight data: flock cohesion and dispersion, arXiv

Excerpt: Several models of flocking have been promoted based on simulations with qualitatively naturalistic behavior. In this paper we provide the first direct application of computational modeling methods to infer flocking behavior from experimental field data. We show that this approach is able to infer general rules for interaction, or lack of interaction, among members of a flock or, more generally, any community. Using experimental field measurements of homing pigeons in flight we demonstrate the existence of a basic distance dependent attraction/repulsion relationship and show that this rule is sufficient to explain collective behavior observed in nature.
See Also: Hierarchical group dynamics in pigeon flocks

• Source: Dynamical modeling of collective behavior from pigeon flight data: flock cohesion and dispersion, Graciano Dieck Kattas, Xiao-Ke Xu and Michael Small, arXiv:1110.1739, 2011/10/8

Stuart Kauffman - The End Of A Physics Worldview: Heraclitus and the Watershed of Life, NECSI

Excerpt: At the dawn of Western philosophy and science, some 2,700 years ago, Heraclitus, declared that, "the world bubbles forth." There is, in this fragment of thought, a natural magic, a creativity beyond the entailing laws of modern physics. I believe Heraclitus was right about the evolution of the biosphere and human life. We live beyond entailing law in a natural magic we co-create.

• Source: Stuart Kauffman - The End Of A Physics Worldview: Heraclitus and the Watershed of Life, NECSI Seminar, 2011/10/19
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Bombings, beheadings? Stats show a peaceful world, Physorg.com

Excerpt: Yes, thousands of people have died in bloody unrest from Africa to Pakistan, while terrorists plot bombings and kidnappings. Wars drag on in Iraq and Afghanistan. In peaceful Norway, a man massacred 69 youths in July. In Mexico, headless bodies turn up, victims of drug cartels. This month eight people died in a shooting in a California hair salon.
Yet, historically, we've never had it this peaceful.
That's the thesis of three new books, including one by prominent Harvard psychologist Steven Pinker. Statistics reveal dramatic reductions in war deaths, family violence, racism, rape, murder and all sorts of mayhem.

• Source: Bombings, beheadings? Stats show a peaceful world, Seth Borenstein, Physorg.com, 2011/10/22

Evolution of Networks for Body Plan Patterning; Interplay of Modularity, Robustness and Evolvability, PLoS Comput Biol

Excerpt: An important question in evolutionary developmental biology is how the complex organisms we see around us have evolved, and how this complexity is encoded in their DNA. An often heard statement is that the gene regulatory networks underlying developmental processes are modular; that is, different functions are carried out by largely independent network parts. It is argued that this network modularity allows both for robust functioning and evolutionary tinkering, and that selection thus produces modular networks. Here we use a simulation model for the evolution of animal body plan patterning to investigate these ideas. (…)

• Source: Evolution of Networks for Body Plan Patterning; Interplay of Modularity, Robustness and Evolvability, Kirsten H. ten Tusscher, Paulien Hogeweg, DOI: 10.1371/journal.pcbi.1002208, PLoS Comput Biol 7(10): e1002208, 2011/10/6

10 Unsolved Mysteries, Scientific American

Excerpt: 1. How Did Life Begin?
2. How Do Molecules Form?
3. How Does the Environment Influence Our Genes?
4. How Does the Brain Think and Form Memories?
5. How Many Elements Exist?
6. Can Computers Be Made Out of Carbon?
7. How Do We Tap More Solar Energy?
8. What Is the Best Way to Make Biofuels?
9. Can We Devise New Ways to Create Drugs?
10. Can We Continuously Monitor Our Own Chemistry?

• Source: 10 Unsolved Mysteries, Philip Ball, Scientific American, 2011/10

What we learned from 5 million books, TED.com

About this talk: Have you played with Google Labs' Ngram Viewer? It's an addicting tool that lets you search for words and ideas in a database of 5 million books from across centuries. Erez Lieberman Aiden and Jean-Baptiste Michel show us how it works, and a few of the surprising things we can learn from 500 billion words.

• Source: What we learned from 5 million books, TED.com, 2011/09

Change and Aging Senescence as an Adaptation, PLoS ONE

Excerpt: Understanding why we age is a long-lived open problem in evolutionary biology. Aging is prejudicial to the individual, and evolutionary forces should prevent it, but many species show signs of senescence as individuals age. Here, I will propose a model for aging based on assumptions that are compatible with evolutionary theory.

• Source: Change and Aging Senescence as an Adaptation, Martins ACR, DOI: 10.1371/journal.pone.0024328, PLoS ONE 6(9): e24328, September 2011

Diurnal and Seasonal Mood Vary with Work, Sleep, and Daylength Across Diverse Cultures, Science

Abstract: We identified individual-level diurnal and seasonal mood rhythms in cultures across the globe, using data from millions of public Twitter messages. We found that individuals awaken in a good mood that deteriorates as the day progresses�"which is consistent with the effects of sleep and circadian rhythm�"and that seasonal change in baseline positive affect varies with change in daylength. People are happier on weekends, but the morning peak in positive affect is delayed by 2 hours, which suggests that people awaken later on weekends.

• Source: Diurnal and Seasonal Mood Vary with Work, Sleep, and Daylength Across Diverse Cultures, Scott A. Golder, Michael W. Macy, DOI: 10.1126/science.1202775, Science Vol. 333 no. 6051 pp. 1878-1881, 2011/09/30

Neutrality in evolutionary algorithms… What do we know?, Evolving Systems

Abstract: Over the last years, the effects of neutrality have attracted the attention of many researchers in the Evolutionary Algorithms (EAs) community. A mutation from one gene to another is considered as neutral if this modification does not affect the phenotype. This article provides a general overview on the work carried out on neutrality in EAs. Using as a framework the origin of neutrality and its study in different paradigms of EAs (e.g., Genetic Algorithms, Genetic Programming), we discuss the most significant works and findings on this topic. This work points towards open issues, which we belive the community needs to address.

• Source: Neutrality in evolutionary algorithms… What do we know?, Edgar Galván-López, Riccardo Poli, Ahmed Kattan, Michael O’Neill and Anthony Brabazon, DOI: 10.1007/s12530-011-9030-5, Evolving Systems Volume 2, Number 3, 145-163, 2011/09

A Geometric Approach to Complexity, SFI Working Papers

Abstract: We develop a geometric approach to complexity based on the principle that complexity requires interactions at different scales of description. Complex systems are more than the sum of their parts of any size, and not just more than the sum of their elements. Using information geometry, we therefore analyze the decomposition of a system in terms of an interaction hierarchy. In mathematical terms, we present a theory of complexity measures for finite random fields using the geometric framework of hierarchies of exponential families. Within our framework, previously proposed complexity measures find their natural place and gain a new interpretation.

• Source: A Geometric Approach to Complexity, Nihat Ay, Eckehard Olbrich, Nils Bertschinger, Jürgen Jost, DOI: SFI-WP 11-08-039, SFI Working Papers

Lee Cronin: Making matter come alive, TED.com

About this talk: Before life existed on Earth, there was just matter, inorganic dead "stuff." How improbable is it that life arose? And -- could it use a different type of chemistry? Using an elegant definition of life (anything that can evolve), chemist Lee Cronin is exploring this question by attempting to create a fully inorganic cell using a "Lego kit" of inorganic molecules -- no carbon -- that can assemble, replicate and compete.

• Source: Lee Cronin: Making matter come alive, TED.com, 2011/09
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Edward Tenner: Unintended consequences, TED.com

About this talk: Every new invention changes the world -- in ways both intentional and unexpected. Historian Edward Tenner tells stories that illustrate the under-appreciated gap between our ability to innovate and our ability to foresee the consequences.

• Source: Edward Tenner: Unintended consequences, TED.com, 2011/09
• VIDEO - Watch this talk

Compilado AZyNE 20-08

Harnessed: How Language and Music Mimicked Nature and Transformed Ape to Man, BenBella Books

Summary: Cognitive scientist Changizi demonstrates that human speech has been very specifically "designed" to harness the sounds of nature, sounds we've evolved over millions of years to readily understand. Long before humans evolved, mammals have learned to interpret the sounds of nature to understand both threats and opportunities. Our speech-regardless of language-is very clearly based on the sounds of nature. Even more fascinating, Changizi shows that music itself is based on natural sounds. Music-seemingly one of the most human of inventions-is literally built on sounds and patterns of sound that have existed since the beginning of time.

• Source: Harnessed: How Language and Music Mimicked Nature and Transformed Ape to Man, Mark Changizi, BenBella Books, 2011/08/02

Nest Inheritance Is the Missing Source of Direct Fitness in a Primitively Eusocial Insect, Science

Abstract: Animals that cooperate with nonrelatives represent a challenge to inclusive fitness theory, unless cooperative behavior is shown to provide direct fitness benefits. Inheritance of breeding resources could provide such benefits, but this route to cooperation has been little investigated in the social insects. We show that nest inheritance can explain the presence of unrelated helpers in a classic social insect model, the primitively eusocial wasp Polistes dominulus. We found that subordinate helpers produced more direct offspring than lone breeders, some while still subordinate but most after inheriting the dominant position. Thus, while indirect fitness obtained through helping relatives has been the dominant paradigm for understanding eusociality in insects, direct fitness is vital to explain cooperation in P. dominulus.

• Source: Nest Inheritance Is the Missing Source of Direct Fitness in a Primitively Eusocial Insect, Ellouise Leadbeater, Jonathan M. Carruthers, Jonathan P. Green, Neil S. Rosser, Jeremy Field, DOI: 10.1126/science.1205140, Science Vol. 333 no. 6044 pp. 874-876, 2011/08/12

The ten grand challenges of synthetic life, Systems and Synthetic Biology

Abstract: The construction of artificial life is one of the main scientific challenges of the Synthetic Biology era. Advances in DNA synthesis and a better understanding of regulatory processes make the goal of constructing the first artificial cell a realistic possibility. This would be both a fundamental scientific milestone and a starting point of a vast range of applications, from biofuel production to drug design. However, several major issues might hamper the objective of achieving an artificial cell. From the bottom-up to the selection-based strategies, this work encompasses the ten grand challenges synthetic biologists will have to be aware of in order to cope with the task of creating life in the lab.

• Source: The ten grand challenges of synthetic life, Manuel Porcar, Antoine Danchin, Victor de Lorenzo, Vitor A. dos Santos, Natalio Krasnogor, Steen Rasmussen and Andrés Moya, DOI: 10.1007/s11693-011-9084-5, Systems and Synthetic Biology, Online First, 2011/08/05

Compilado AZyNE 20-07

Ten Simple Rules for Building and Maintaining a Scientific Reputation, PLoS Comput Biol

Excerpt: Rule 1: Think Before You Act
Rule 2: Do Not Ignore Criticism
Rule 3: Do Not Ignore People
Rule 4: Diligently Check Everything You Publish and Take Publishing Seriously
Rule 5: Always Declare Conflicts of Interest
Rule 6: Do Your Share for the CommunityRule
Rule 7: Do Not Commit to Tasks You Cannot Complete
Rule 8: Do Not Write Poor Reviews of Grants and Papers
Rule 9: Do Not Write References for People Who Do Not Deserve It
Rule 10: Never Plagiarize or Doctor Your Data

• Source: Ten Simple Rules for Building and Maintaining a Scientific Reputation, Philip E. Bourne, Virginia Barbour, DOI: 10.1371/journal.pcbi.1002108, PLoS Comput Biol 7(6): e1002108., 2011/06/30

A Universe of Galaxies, Science

Excerpt: It wasn't until the 1920s that astronomers realized that there were other galaxies in the universe besides our own. (...) Nowadays there is no doubt that the universe extends well beyond the confines of the Milky Way and that our galaxy is just one among many. Telescopes much more powerful than those used by Hubble have produced ever-larger and more comprehensive surveys of galaxies. The detailed understanding of our galaxy has also evolved dramatically.

• Source: A Universe of Galaxies, Maria Cruz, Robert Coontz, DOI: 10.1126/science.333.6039.169, Science Vol. 333 no. 6039 p. 169, 2011/07/08

Running with the Red Queen: Host-Parasite Coevolution Selects for Biparental Sex, Science

Abstract: Most organisms reproduce through outcrossing, even though it comes with substantial costs. The Red Queen hypothesis proposes that selection from coevolving pathogens facilitates the persistence of outcrossing despite these costs. We used experimental coevolution to test the Red Queen hypothesis and found that coevolution with a bacterial pathogen (Serratia marcescens) resulted in significantly more outcrossing in mixed mating experimental populations of the nematode Caenorhabditis elegans. Furthermore, we found that coevolution with the pathogen rapidly drove obligately selfing populations to extinction, whereas outcrossing populations persisted through reciprocal coevolution. Thus, consistent with the Red Queen hypothesis, coevolving pathogens can select for biparental sex.

• Source: Running with the Red Queen: Host-Parasite Coevolution Selects for Biparental Sex, Levi T. Morran, Olivia G. Schmidt, Ian A. Gelarden, Raymond C. Parrish II, Curtis M. Lively, DOI: 10.1126/science.1206360, Science Vol. 333 no. 6039 pp. 216-218, 2011/07/08

Compilado AZyNE 30-03

Co-Residence Patterns in Hunter-Gatherer Societies Show Unique Human Social Structure, Science

Abstract: Contemporary humans exhibit spectacular biological success derived from cumulative culture and cooperation. The origins of these traits may be related to our ancestral group structure. Because humans lived as foragers for 95% of our species’ history, we analyzed co-residence patterns among 32 present-day foraging societies (total n = 5067 individuals, mean experienced band size = 28.2 adults). We found that hunter-gatherers display a unique social structure where (i) either sex may disperse or remain in their natal group, (ii) adult brothers and sisters often co-reside, and (iii) most individuals in residential groups are genetically unrelated. These patterns produce large interaction networks of unrelated adults and suggest that inclusive fitness cannot explain extensive cooperation in hunter-gatherer bands. However, large social networks may help to explain why humans evolved capacities for social learning that resulted in cumulative culture.

• Source: Co-Residence Patterns in Hunter-Gatherer Societies Show Unique Human Social Structure, Kim R. Hill, Robert S. Walker, Miran Božičević, James Eder, Thomas Headland, Barry Hewlett, A. Magdalena Hurtado, Frank Marlowe, Polly Wiessner, and Brian Wood, DOI: 10.1126/science.1199071, Science Vol. 331 no. 6022 pp. 1286-1289, 2011/03/11

Danny Hillis: Understanding cancer through proteomics, TED.com

About this talk: Danny Hills makes a case for the next frontier of cancer research: proteomics, the study of proteins in the body. As Hillis explains it, genomics shows us a list of the ingredients of the body -- while proteomics shows us what those ingredients produce. Understanding what's going on in your body at the protein level may lead to a new understanding of how cancer happens.

• Source: Danny Hillis: Understanding cancer through proteomics, TED.com, 2011/03
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Deb Roy: The birth of a word, TED.com

About this talk: MIT researcher Deb Roy wanted to understand how his infant son learned language -- so he wired up his house with videocameras to catch every moment (with exceptions) of his son's life, then parsed 90,000 hours of home video to watch "gaaaa" slowly turn into "water." Astonishing, data-rich research with deep implications for how we learn.

• Source: Deb Roy: The birth of a word, TED.com, 2011/03
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Has the Earth’s sixth mass extinction already arrived?, Nature

Abstract: Palaeontologists characterize mass extinctions as times when the Earth loses more than three-quarters of its species in a geologically short interval, as has happened only five times in the past 540 million years or so. Biologists now suggest that a sixth mass extinction may be under way, given the known species losses over the past few centuries and millennia. Here we review how differences between fossil and modern data and the addition of recently available palaeontological information influence our understanding of the current extinction crisis. Our results confirm that current extinction rates are higher than would be expected from the fossil record, highlighting the need for effective conservation measures.

• Source: Has the Earth’s sixth mass extinction already arrived?, Anthony D. Barnosky, Nicholas Matzke, Susumu Tomiya, Guinevere O. U. Wogan, Brian Swartz, Tiago B. Quental, Charles Marshall, Jenny L. McGuire, Emily L. Lindsey, Kaitlin C. Maguire, Ben Mersey & Elizabeth A. Ferrer, DOI: 10.1038/nature09678, Nature 471, 51�"57, 2011/03/03

Nonlinear deterministic equations in biological evolution, arXiv

Abstract: We review models of biological evolution in which the population frequency changes deterministically with time. If the population is self-replicating, although the equations for simple prototypes can be linearised, nonlinear equations arise in many complex situations. For sexual populations, even in the simplest setting, the equations are necessarily nonlinear due to the mixing of the parental genetic material. The solutions of such nonlinear equations display interesting features such as multiple equilibria and phase transitions. We mainly discuss those models for which an analytical understanding of such nonlinear equations is available.

• Source: Nonlinear deterministic equations in biological evolution, Kavita Jain and Sarada Seetharaman, arXiv:1103.0097, 2011/03/01

Selection for smaller brains in Holocene human evolution, arXiv

Abstract: Background: Human populations during the last 10,000 years have undergone rapid decreases in average brain size as measured by endocranial volume or as estimated from linear measurements of the cranium. A null hypothesis to explain the evolution of brain size is that reductions result from genetic correlation of brain size with body mass or stature.
Results: The absolute change of endocranial volume in the study samples was significantly greater than would be predicted from observed changes in body mass or stature.
Conclusions: The evolution of smaller brains in many recent human populations must have resulted from selection upon brain size itself or on other features more highly correlated with brain size than are gross body dimensions. This selection may have resulted from energetic or nutritional demands in Holocene populations, or to life history constraints on brain development.

• Source: Selection for smaller brains in Holocene human evolution, John Hawks, arXiv:1102.5604, 2011/02/28

Compilado AZyNE 29-01

The Newest Synthesis: Understanding the Interplay of Evolutionary and Ecological Dynamics, Science

Excerpt: The effect of ecological change on evolution has long been a focus of scientific research. The reverse�"how evolutionary dynamics affect ecological traits�"has only recently captured our attention, however, with the realization that evolution can occur over ecological time scales. This newly highlighted causal direction and the implied feedback loop�"eco-evolutionary dynamics�"is invigorating both ecologists and evolutionists and blurring the distinction between them.

• Source: The Newest Synthesis: Understanding the Interplay of Evolutionary and Ecological Dynamics, Thomas W. Schoener, DOI: 10.1126/science.1193954, Science Vol. 331 no. 6016 pp. 426-429, 2011/01/28

Swarm intelligence in plant roots, Trends in Ecology & Evolution

Excerpt: (...) swarm intelligence occurs when two or more individuals independently, or at least partly independently, acquire information that is processed through social interactions and is used to solve a cognitive problem in a way that would be impossible for isolated individuals. We propose at least one example of swarm intelligence in plants: coordination of individual roots in complex root systems.

• Source: Swarm intelligence in plant roots, František Baluška, Simcha Lev-Yadun, Stefano Mancuso, DOI: 10.1016/j.tree.2010.09.003, Trends in Ecology & Evolution, Volume 25, Issue 12, 682-683, 2010/12

Primitive agriculture in a social amoeba, Nature

Excerpt: Here we show that the social amoeba Dictyostelium discoideum has a primitive farming symbiosis that includes dispersal and prudent harvesting of the crop. About one-third of wild-collected clones engage in husbandry of bacteria. Instead of consuming all bacteria in their patch, they stop feeding early and incorporate bacteria into their fruiting bodies. They then carry bacteria during spore dispersal and can seed a new food crop, which is a major advantage if edible bacteria are lacking at the new site.

• Source: Primitive agriculture in a social amoeba, Debra A. Brock, Tracy E. Douglas, David C. Queller & Joan E. Strassmann, DOI: 10.1038/nature09668, Nature 469, 393�"396, 2011/01/19

Infectious moods: How bugs control your mind, New Scientist

Excerpt: Now it seems the immune system, and infections that stimulate it, can influence our moods, memory and ability to learn. Some strange behaviours, such as obsessive compulsive disorder, may be triggered by infections, and the immune system may even shape our basic personalities, such as how anxious or impulsive we are.

• Source: Infectious moods: How bugs control your mind, New Scientist, 2011/01/12

Morphological change in machines accelerates the evolution of robust behavior, PNAS

Excerpt: Most animals exhibit significant neurological and morphological change throughout their lifetime. No robots to date, however, grow new morphological structure while behaving. This is due to technological limitations but also because it is unclear that morphological change provides a benefit to the acquisition of robust behavior in machines. Here I show that in evolving populations of simulated robots, if robots grow from anguilliform into legged robots during their lifetime in the early stages of evolution, and the anguilliform body plan is gradually lost during later stages of evolution, gaits are evolved for the final, legged form of the robot more rapidly�"and the evolved gaits are more robust�"compared to evolving populations of legged robots that do not transition through the anguilliform body plan.

• Source: Morphological change in machines accelerates the evolution of robust behavior, Josh Bongard, DOI: 10.1073/pnas.1015390108, PNAS Published online before print, 2011/01/10
• VIDEO - A typical gait discovered for the hexapod when it experiences ontogenetic and topological change: It transitions from the legless form into an upright legged form over its lifetime.

Complexity through Recombination: From Chemistry to Biology, Entropy

Abstract: Recombination is a common event in nature, with examples in physics, chemistry, and biology. This process is characterized by the spontaneous reorganization of structural units to form new entities. Upon reorganization, the complexity of the overall system can change. In particular the components of the system can now experience a new response to externally applied selection criteria, such that the evolutionary trajectory of the system is altered. The link between chemical and biological forms of recombination is explored. (...) The results underscore the importance of recombination in the origins of life on the Earth and its subsequent evolutionary divergence.

• Source: Complexity through Recombination: From Chemistry to Biology, Niles Lehman et al., DOI: 10.3390/e13010017, Entropy, vol. 13, issue 1, pages 17-37, 2011/01/01

Mating strategies in primates: A game theoretical approach to infanticide, Journal of Theoretical Biology

Excerpt: Infanticide by newly immigrated or newly dominant males is reported among a variety of taxa, such as birds, rodents, carnivores and primates. Here we present a game theoretical model to explain the presence and prevalence of infanticide in primate groups. We have formulated a three-player game involving two males and one female and show that the strategies of infanticide on the males' part and polyandrous mating on the females' part emerge as Nash equilibria that are stable under certain conditions [...] These conclusions are confirmed by observations in the wild. These conclusions are confirmed by observations in the wild.

• Source: Mating strategies in primates: A game theoretical approach to infanticide, Lyon JE, Pandit SA, van Schaik CP, Pradhan GR, DOI: 10.1016/j.jtbi.2011.01.005, Journal of Theoretical Biology, in Press, January 2011

Peer review: Trial by Twitter, Nature

Summary: Blogs and tweets are ripping papers apart within days of publication, leaving researchers unsure how to react.

• Source: Peer review: Trial by Twitter, Apoorva Mandavilli, DOI: 10.1038/469286a, Nature 469, 286-287, 2011/01/19