Darwinian Ascension
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PLOS Biology: Contesting the “Nature” Of Conformity: What Milgram and Zimbardo's Studies Really Show

Understanding of the psychology of tyranny is dominated by classic studies from the 1960s and 1970s: Milgram's research on obedience to authority and Zimbardo's Stanford Prison Experiment. Supporting popular notions of the banality of evil, this research has been taken to show that people conform passively and unthinkingly to both the instructions and the roles that authorities provide, however malevolent these may be. Recently, though, this consensus has been challenged by empirical work informed by social identity theorizing. This suggests that individuals' willingness to follow authorities is conditional on identification with the authority in question and an associated belief that the authority is right.

 

 

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Adaptation to a new environment allows cooperators to purge cheaters stochastically

Cooperation via production of common goods is found in diverse life forms ranging from viruses to social animals. However, natural selection predicts a “tragedy of the commons”: Cheaters, benefiting from without producing costly common goods, are more fit than cooperators and should destroy cooperation. In an attempt to discover novel mechanisms of cheater control, we eliminated known ones using a yeast cooperator–cheater system engineered to supply or exploit essential nutrients. Surprisingly, although less fit than cheaters, cooperators quickly dominated a fraction of cocultures. Cooperators isolated from these cocultures were superior to the cheater isolates they had been cocultured with, even though these cheaters were superior to ancestral cooperators. Resequencing and phenotypic analyses revealed that evolved cooperators and cheaters all harbored mutations adaptive to the nutrient-limited cooperative environment, allowing growth at a much lower concentration of nutrient than their ancestors. Even after the initial round of adaptation, evolved cooperators still stochastically dominated cheaters derived from them. We propose the “adaptive race” model: If during adaptation to an environment, the fitness gain of cooperators exceeds that of cheaters by at least the fitness cost of cooperation, the tragedy of the commons can be averted. Although cooperators and cheaters sample from the same pool of adaptive mutations, this symmetry is soon broken: The best cooperators purge cheaters and continue to grow, whereas the best cheaters cause rapid self-extinction. We speculate that adaptation to changing environments may contribute to the persistence of cooperative systems before the appearance of more sophisticated mechanisms of cheater control.

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Evolution of the human-specific microRNA miR-941 : Nature Communications : Nature Publishing Group

Evolution of the human-specific microRNA miR-941 : Nature Communications : Nature Publishing Group | Darwinian Ascension | Scoop.it

MicroRNA-mediated gene regulation is important in many physiological processes. Here we explore the roles of a microRNA, miR-941, in human evolution. We find that miR-941 emerged de novo in the human lineage, between six and one million years ago, from an evolutionarily volatile tandem repeat sequence. Its copy-number remains polymorphic in humans and shows a trend for decreasing copy-number with migration out of Africa. Emergence of miR-941 was accompanied by accelerated loss of miR-941-binding sites, presumably to escape regulation. We further show that miR-941 is highly expressed in pluripotent cells, repressed upon differentiation and preferentially targets genes in hedgehog- and insulin-signalling pathways, thus suggesting roles in cellular differentiation. Human-specific effects of miR-941 regulation are detectable in the brain and affect genes involved in neurotransmitter signalling. Taken together, these results implicate miR-941 in human evolution, and provide an example of rapid regulatory evolution in the human linage.

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Darwinian Ascension

Darwinian Ascension | Darwinian Ascension | Scoop.it

Besides this Scoop.it  on Darwninian Ascension I just started a Blog on the same subject.

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The Biological Origin of Linguistic Diversity

In contrast with animal communication systems, diversity is characteristic of almost every aspect of human language. Languages variously employ tones, clicks, or manual signs to signal differences in meaning; some languages lack the noun-verb distinction (e.g., Straits Salish), whereas others have a proliferation of fine-grained syntactic categories (e.g., Tzeltal); and some languages do without morphology (e.g., Mandarin), while others pack a whole sentence into a single word (e.g., Cayuga). A challenge for evolutionary biology is to reconcile the diversity of languages with the high degree of biological uniformity of their speakers. Here, we model processes of language change and geographical dispersion and find a consistent pressure for flexible learning, irrespective of the language being spoken. This pressure arises because flexible learners can best cope with the observed high rates of linguistic change associated with divergent cultural evolution following human migration. Thus, rather than genetic adaptations for specific aspects of language, such as recursion, the coevolution of genes and fast-changing linguistic structure provides the biological basis for linguistic diversity. Only biological adaptations for flexible learning combined with cultural evolution can explain how each child has the potential to learn any human language.

 

Baronchelli A, Chater N, Pastor-Satorras R, Christiansen MH (2012) The Biological Origin of Linguistic Diversity. PLoS ONE 7(10): e48029. http://dx.doi.org/10.1371/journal.pone.0048029


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Computational models increasingly improving research, healthcare quality - FierceHealthIT

Computational models are increasingly helping healthcare researchers to understand how to both identify and treat complex diseases, according to Johns Hopkins professors.
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An integrated map of genetic variation from 1,092 human genomes : Nature : Nature Publishing Group

An integrated map of genetic variation from 1,092 human genomes : Nature : Nature Publishing Group | Darwinian Ascension | Scoop.it

Here we describe the genomes of 1,092 individuals from 14 populations, constructed using a combination of low-coverage whole-genome and exome sequencing. By developing methods to integrate information across several algorithms and diverse data sources, we provide a validated haplotype map of 38|[thinsp]|million single nucleotide polymorphisms, 1.4|[thinsp]|million short insertions and deletions, and more than 14,000 larger deletions. We show that individuals from different populations carry different profiles of rare and common variants, and that low-frequency variants show substantial geographic differentiation, which is further increased by the action of purifying selection. We show that evolutionary conservation and coding consequence are key determinants of the strength of purifying selection, that rare-variant load varies substantially across biological pathways, and that each individual contains hundreds of rare non-coding variants at conserved sites, such as motif-disrupting changes in transcription-factor-binding sites. This resource, which captures up to 98% of accessible single nucleotide polymorphisms at a frequency of 1% in related populations, enables analysis of common and low-frequency variants in individuals from diverse, including admixed, populations.

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How Information Theory Handles Cell Signaling and Uncertainty

Also see the rather stupid reply from the Discovery Institute. Really, how can ya pretend to be scientific when you write such replies: "

Yet notice that the only cases of systems where we observe optimization of signal to noise are (1) life and (2) human-engineered communication systems. Is lightning a communication channel from cloud to ground? No. Does it care about the carrying capacity of signal to noise? The idea is laughable. So is any other nonliving example of transfer of material: a star leaking its contents into a black hole, a river flowing from the mountains to the ocean, chunks of Mars arriving on Earth as meteorites. None of these are amenable to information theory. Environmental factors and laws of physics may act as constraints, but they do not optimize.

The uniqueness of optimization in signaling strengthens the argument for intelligent design in cellular communication as is self-evident in human-designed communication systems (e.g., software and computer networks). This is not to claim cells are intelligent, but rather to say they bear the stamp of purposeful design, just as a radio or smartphone does."

 

First of all it is incorrect, there are other systems where noise and signal are optimized (please define signal and noise...), second even IF that would be so does not logically result in an argument pro ID, and third, evolution has to result in optimization, that is logical and also in an increase of complexity (hence will often end up in life).

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Metazoan opsin evolution reveals a simple route to animal vision

Of course this should not be seen as evidence for a single lineage of development of eyesight. It appears that "All known visual pigments in Neuralia (Cnidaria, Ctenophora, and Bilateria) are composed of an opsin (a seven-transmembrane G protein-coupled receptor), and a light-sensitive chromophore, generally retinal." and that all opsins share the same common ancestor but that is only part of the deal. ZME has a nice further tutorial on the development of eye sight: http://www.zmescience.com/medicine/genetic/evolution-of-vision-from-700-million-years/

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A simple model clarifies the complicated relationships of complex networks

Researchers have discovered many types of complex networks and have proposed hundreds of models to explain their origins, yet most of the relationships within each of these types are still uncertain. Furthermore, because of the large number of types and models of complex networks, it is widely thought that these complex networks cannot all share a simple universal explanation. However, here we find that a simple model can produce many types of complex networks, including scale-free, small-world, ultra small-world, Delta-distribution, compact, fractal, regular and random networks, and by revising this model, we show that one can produce community-structure networks. Using this model and its revised versions, the complicated relationships among complex networks can be illustrated. Given that complex networks are regarded as a model tool of complex systems, the results here bring a new perspective to understanding the power law phenomena observed in various complex systems.

 

A simple model clarifies the complicated relationships of complex networks

Bojin Zheng, Hongrun Wu, Jun Qin, Wenhua Du, Jianmin Wang, Deyi Li

http://arxiv.org/abs/1210.3121


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Low fertility increases descendant socioeconomic position but reduces long-term fitness in a modern post-industrial society

Adaptive accounts of modern low human fertility argue that small family size maximizes the inheritance of socioeconomic resources across generations and may consequently increase long-term fitness. This study explores the long-term impacts of fertility and socioeconomic position (SEP) on ...


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Selectively altering belief formation in the human brain

Humans form beliefs asymmetrically; we tend to discount bad news but embrace good news. This reduced impact of unfavorable information on belief updating may have important societal implications, including the generation of financial market bubbles, ill preparedness in the face of natural disasters, and overly aggressive medical decisions. Here, we selectively improved people’s tendency to incorporate bad news into their beliefs by disrupting the function of the left (but not right) inferior frontal gyrus using transcranial magnetic stimulation, thereby eliminating the engrained “good news/bad news effect.” Our results provide an instance of how selective disruption of regional human brain function paradoxically enhances the ability to incorporate unfavorable information into beliefs of vulnerability.

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Understanding the placebo effect from an evolutionary perspective

Understanding the placebo effect from an evolutionary perspective | Darwinian Ascension | Scoop.it
Evolution & Human Behavior, Volume null, Issue null, Pages null, null, Authors:Pete C. Trimmer; James A.R. Marshall; Lutz Fromhage; John M. McNamara; Alasdair I.
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Somatic Mosaicism: Genetic Differences Between Individual Cells

 

The cells in the body of a healthy person all have the same DNA, right? Not really! It has been known for quite some time now that there are genetic differences between cells within one person.

 

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On the necessity of complexity

Wolfram's Principle of Computational Equivalence (PCE) implies that universal complexity abounds in nature. This paper comprises three sections. In the first section we consider the question why there are so many universal phenomena around. So, in a sense, we week a driving force behind the PCE if any. We postulate a principle GNS that we call the Generalized Natural Selection Principle that together with the Church-Turing Thesis is seen to be equivalent to a weak version of PCE. In the second section we ask the question why we do not observe any phenomena that are complex but not-universal. We choose a cognitive setting to embark on this question and make some analogies with formal logic. In the third and final section we report on a case study where we see rich structures arise everywhere.

 

On the necessity of complexity

Joost J. Joosten

http://arxiv.org/abs/1211.1878


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Magazine, Science, Science and Technology | The descent of Edward Wilson | Prospect Magazine

Magazine, Science, Science and Technology | The descent of Edward Wilson | Prospect Magazine | Darwinian Ascension | Scoop.it

Dawkins on Edward O Wilsons newest book. Great stuff!

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Competition between species can stabilize public-goods cooperation within a species

Competition between species can stabilize public-goods cooperation within a species | Darwinian Ascension | Scoop.it

Cooperative phenotypes are found to be favored in a yeast population grown in the presence of a bacterial species. The bacteria drive cooperation within yeast by competing for essential resources and by limiting the access of cheaters to the public goods produced by cooperating yeast cells.

 

 

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Detecting Causality in Complex Ecosystems

Identifying causal networks is important for effective policy and management recommendations on climate, epidemiology, financial regulation, and much else. We introduce a method, based on nonlinear state space reconstruction, that can distinguish causality from correlation. It extends to nonseparable weakly connected dynamic systems (cases not covered by the current Granger causality paradigm). The approach is illustrated both by simple models (where, in contrast to the real world, we know the underlying equations/relations and so can check the validity of our method) and by application to real ecological systems, including the controversial sardine-anchovy-temperature problem.

 

Detecting Causality in Complex Ecosystems
George Sugihara, Robert May, Hao Ye, Chih-hao Hsieh, Ethan Deyle, Michael Fogarty, Stephan Munch

Science 26 October 2012:
Vol. 338 no. 6106 pp. 496-500
http://dx.doi.org/10.1126/science.1227079


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Synthetic Biology – A Recipe for Disaster or Biosolution for the Future? | Roundtable Review

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Did bacteria spark evolution of multicellular life?

Did bacteria spark evolution of multicellular life? | Darwinian Ascension | Scoop.it
A new study suggests that bacteria may have helped kick off one of the key events in evolution: the leap from one-celled organisms to many-celled organisms, a development that eventually led to animals, including humans.
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Mesoscale symmetries explain dynamical equivalence of food webs

A goal of complex system research is to identify the dynamical implications of network structure. While early results focused mainly on local or global structural properties, there is now growing interest in mesoscale structures that comprise more than one node but not the whole network. A central challenge is to discover under what conditions the occurrence of a specific mesoscale motif already allows conclusions on the dynamics of a network as a whole. In this paper, we investigate the dynamics of ecological food webs, complex heterogeneous networks of interacting populations.

 

Mesoscale symmetries explain dynamical equivalence of food webs

Helge Aufderheide, Lars Rudolf and Thilo Gross

New J. Phys. 14 105014

http://dx.doi.org/10.1088/1367-2630/14/10/105014


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Slimed! Scientists Discover that Evolution of Memory Started by Feedback from Chemicals

Slimed! Scientists Discover that Evolution of Memory Started by Feedback from Chemicals | Darwinian Ascension | Scoop.it
Although They only have a single cell and no brain, slime molds, Physarum polycephalum, remember where they’ve been by constructing a form of spatial memory by avoiding areas it has previously explored, according to researchers at University of...
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Artificially Intelligent Game Bots Pass the Turing Test on Turing’s Centenary | News

Artificially Intelligent Game Bots Pass the Turing Test on Turing’s Centenary | News | Darwinian Ascension | Scoop.it
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Evolution of cooperation and skew under imperfect information

The evolution of cooperation in nature and human societies depends crucially on how the benefits from cooperation are divided and whether individuals have complete information about their payoffs. We tackle these questions by adopting a methodology from economics called mechanism design. Focusing on reproductive skew as a case study, we show that full cooperation may not be achievable due to private information over individuals’ outside options, regardless of the details of the specific biological or social interaction. Further, we consider how the structure of the interaction can evolve to promote the maximum amount of cooperation in the face of the informational constraints. Our results point to a distinct avenue for investigating how cooperation can evolve when the division of benefits is flexible and individuals have private information.

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