Geração de formas de complexidade através da resolução de conflitos teciduais: mero acaso, fortuita necessidade ou design inteligente?

terça-feira, fevereiro 21, 2017

Generation of shape complexity through tissue conflict resolution

Alexandra B Rebocho Paul Southam J Richard Kennaway J Andrew Bangham Enrico Coen 

John Innes Centre, England; University of East Anglia, England

Published February 7, 2017

Cite as eLife 2017;6:e20156


Out-of-plane tissue deformations are key morphogenetic events during plant and animal development that generate 3D shapes, such as flowers or limbs. However, the mechanisms by which spatiotemporal patterns of gene expression modify cellular behaviours to generate such deformations remain to be established. We use the Snapdragon flower as a model system to address this problem. Combining cellular analysis with tissue-level modelling, we show that an orthogonal pattern of growth orientations plays a key role in generating out-of-plane deformations. This growth pattern is most likely oriented by a polarity field, highlighted by PIN1 protein localisation, and is modulated by dorsoventral gene activity. The orthogonal growth pattern interacts with other patterns of differential growth to create tissue conflicts that shape the flower. Similar shape changes can be generated by contraction as well as growth, suggesting tissue conflict resolution provides a flexible morphogenetic mechanism for generating shape diversity in plants and animals.

eLife digest

Plant and animal organs come in many different shapes, from pitcher-shaped leaves and butterfly wings, to orchid flowers and the convoluted shape of the brain. Unlike pottery or sculpture, no external hand guides the formation of these biological structures; they arise on their own, through sheets of cells developing into particular three-dimensional shapes. But how does this process of self-making operate? We know that patterns of gene activity are important, because mutations that disrupt these patterns change the shape of the organ. But it is not clear how these patterns lead to sheets of cells curving and bending themselves into their characteristic three-dimensional shapes.

Plants are particularly useful tools for studying how three-dimensional organs form because, unlike animals, their cells do not slide relative to each other, which makes the analysis simpler. Rebocho et al. used a combination of computational modelling and cell analysis to study how the intricately shaped flowers of plants known as Snapdragons form. The experiments show that genes control the shape of Snapdragon flowers by causing groups of cells to grow at different rates and in different directions. This pattern of growth creates internal conflicts that are resolved by sheets of cells curving in particular ways, accounting for the three-dimensional shape.

Rebocho et al. propose that the principles of tissue conflict resolution described in this work may also underlie the development and evolution of many other plant and animal organ shapes. A future challenge is to identify the cellular mechanisms that link patterns of gene activity to the generation and resolution of conflicting cell behaviours.


Contra a Associação Brasileira Cristãos na Ciência, este livro critica o teísmo evolucionista científica, filosófica e teologicamente

segunda-feira, fevereiro 20, 2017

Theistic Evolution: A Scientific, Philosophical, and Theological Critique

Edited by J. P. Moreland, Stephen C. Meyer, Chris Shaw, Wayne Grudem

Format: Printed Caseside

Availability: Forthcoming

Expected: Nov 30, 2017

Retail Price: $55.00

About Theistic Evolution

The debate about biological origins continues to be hotly contested within the Christian church. Prominent organizations such as Biologos (USA) and Faraday Institute (UK) insist that Christians must yield to an unassailable scientific consensus in favor of contemporary evolutionary theory and modify traditional biblical ideas about the creation of life accordingly. They promote a view known as “theistic evolution” or “evolutionary creation.” They argue that God used—albeit in an undetectable way—evolutionary mechanisms to produce all forms of life. This book contests this proposal. Featuring two dozen highly credentialed scientists, philosophers, and theologians from Europe and North America, this volume provides the most comprehensive critique of theistic evolution yet produced. It documents evidential, logical, and theological problems with theistic evolution, opening the door to scientific and theological alternatives—making the book essential reading for understanding this worldview-shaping issue.



J. P. Moreland (PhD, University of Southern California) is distinguished professor of philosophy at Biola University. He is an author of, contributor to, or editor of over ninety books, including The Soul: How We Know It's Real and Why It Matters.

Stephen Meyer (PhD, University of Cambridge) is the director of the Discovery Institute's Center of Science and Culture. He is the author of several books, including the best-selling Darwin's Doubt and Signature in the Cell.

Chris Shaw (PhD, Queen's University, Belfast) is professor of drug discovery in the school of pharmacy at Queen's University in Belfast. He is the author of hundreds of peer-reviewed papers and the cofounder of a biomarker discovery company.

Wayne Grudem (PhD, University of Cambridge; DD, Westminster Theological Seminary) is research professor of theology and biblical studies at Phoenix Seminary, having previously taught for 20 years at Trinity Evangelical Divinity School. He is the former president of the Evangelical Theological Society, a member of the Translation Oversight Committee for the English Standard Version of the Bible, the general editor of the ESV Study Bible, and has published over 20 books. 


Category: Academic

Format: Printed Caseside

Page Count: 800

ISBN-10: 1-4335-5286-8

ISBN-13: 978-1-4335-5286-1

Size: 6.0 in x 9.0 in

Weight: 24.0 ounces

Published: November 30, 2017

Darwin, os mecanismos celulares e moleculares do desenvolvimento das lentes de vertebrados: mero acaso, fortuita necessidade ou design inteligente?

The cellular and molecular mechanisms of vertebrate lens development

Aleš Cvekl, Ruth Ashery-Padan

Development 2014 141: 4432-4447; doi: 10.1242/dev.107953


The ocular lens is a model system for understanding important aspects of embryonic development, such as cell specification and the spatiotemporally controlled formation of a three-dimensional structure. The lens, which is characterized by transparency, refraction and elasticity, is composed of a bulk mass of fiber cells attached to a sheet of lens epithelium. Although lens induction has been studied for over 100 years, recent findings have revealed a myriad of extracellular signaling pathways and gene regulatory networks, integrated and executed by the transcription factor Pax6, that are required for lens formation in vertebrates. This Review summarizes recent progress in the field, emphasizing the interplay between the diverse regulatory mechanisms employed to form lens progenitor and precursor cells and highlighting novel opportunities to fill gaps in our understanding of lens tissue morphogenesis.

FREE PDF GRATIS: Development

Se o design na natureza é ilusão, por que buscar design para robôs em miriápodes?

Decentralized control scheme for myriapod robot inspired by adaptive and resilient centipede locomotion

Kotaro Yasui , Kazuhiko Sakai, Takeshi Kano, Dai Owaki, Akio Ishiguro

Published: February 2, 2017


Recently, myriapods have attracted the attention of engineers because mobile robots that mimic them potentially have the capability of producing highly stable, adaptive, and resilient behaviors. The major challenge here is to develop a control scheme that can coordinate their numerous legs in real time, and an autonomous decentralized control could be the key to solve this problem. Therefore, we focus on real centipedes and aim to design a decentralized control scheme for myriapod robots by drawing inspiration from behavioral experiments on centipede locomotion under unusual conditions. In the behavioral experiments, we observed the response to the removal of a part of the terrain and to amputation of several legs. Further, we determined that the ground reaction force is significant for generating rhythmic leg movements; the motion of each leg is likely affected by a sensory input from its neighboring legs. Thus, we constructed a two-dimensional model wherein a simple local reflexive mechanism was implemented in each leg. We performed simulations by using this model and demonstrated that the myriapod robot could move adaptively to changes in the environment and body properties. Our findings will shed new light on designing adaptive and resilient myriapod robots that can function under various circumstances.

Citation: Yasui K, Sakai K, Kano T, Owaki D, Ishiguro A (2017) Decentralized control scheme for myriapod robot inspired by adaptive and resilient centipede locomotion. PLoS ONE 12(2): e0171421. doi:10.1371/journal.pone.0171421

Editor: Jian Jing, Nanjing University, CHINA

Received: March 31, 2016; Accepted: January 20, 2017; Published: February 2, 2017

Copyright: © 2017 Yasui et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the paper and its Supporting Information files.

Funding: This work was supported by Japan Science and Technology Agency, CREST ( to AI. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.


Especiação de gorgulhos da Madeira - novos ícones evolucionários a la "tentilhões de Darwin"?

sábado, fevereiro 18, 2017

ZooKeys 651: 1-77 (02 Feb 2017)

Phylogenetic analysis of the genus Laparocerus, with comments on colonisation and diversification in Macaronesia (Coleoptera, Curculionidae, Entiminae)

expand article infoAntonio Machado‡, Eduardo Rodríguez-Expósito§, Mercedes López§, Mariano Hernández§|

‡ Unaffiliated, La Laguna, Spain

§ Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, La Laguna, Spain

| Universidad de La Laguna, La Laguna, Spain

Corresponding author: Antonio Machado ( )

Academic editor: Miguel Alonso-Zarazaga

© 2017 Antonio Machado, Eduardo Rodríguez-Expósito, Mercedes López, Mariano Hernández.

This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Citation: Machado A, Rodríguez-Expósito E, López M, Hernández M (2017) Phylogenetic analysis of the genus Laparocerus, with comments on colonisation and diversification in Macaronesia (Coleoptera, Curculionidae, Entiminae). ZooKeys 651: 1-77.

ZooBank: urn:

Source/Fonte: Dr. Antonio Machado


The flightless Entiminae weevil genus Laparocerus is the species-richest genus, with 237 species and subspecies, inhabiting Macaronesia (Madeira archipelago, Selvagens, Canary Islands) and the continental ‘Macaronesian enclave’ in Morocco (one single polytypic species). This is the second contribution to gain insight of the genus and assist in its systematic revision with a mitochondrial phylogenetic analysis. It centres on the Canarian clade, adding the 12S rRNA gene to the combined set of COII and 16S rRNA used in our first contribution on the Madeiran clade (here re-analysed). The nuclear 28S rRNA was also used to produce an additional 4-gene tree to check coherency with the 3-gene tree.

A total of 225 taxa (95%) has been sequenced, mostly one individual per taxa. Plausible explanations for incoherent data (mitochondrial introgressions, admixture, incomplete lineage sorting, etc.) are discussed for each of the monophyletic subclades that are coincident with established subgenera, or are restructured or newly described. The overall mean genetic divergence (p-distance) among species is 8.2%; the mean divergence within groups (subgenera) ranks from 2.9 to 7.0% (average 4.6%), and between groups, from 5.4% to 12.0% (average 9.2%). A trustful radiation event within a young island (1.72 Ma) was used to calibrate and produce a chronogram using the software RelTime.

These results confirm the monophyly of both the Madeiran (36 species and subspecies) and the Canarian (196 species and subspecies) clades, which originated ca. 11.2 Ma ago, and started to radiate in their respective archipelagos ca. 8.5 and 7.7 Ma ago. The Madeiran clade seems to have begun in Porto Santo, and from there it jumped to the Desertas and to Madeira, with additional radiations. The Canarian clade shows a sequential star-shape radiation process generating subclades with a clear shift from East to West in coherence with the decreasing age of the islands. Laparocerus garretai from the Selvagens belongs to a Canarian subclade, and Laparocerus susicus from Morocco does not represent the ancestral continental lineage, but a back-colonisation from the Canaries to Africa. Dispersal processes, colonisation patterns, and ecological remarks are amply discussed. Diversification has been adaptive as well as non-adaptive, and the role of ’geological turbulence’ is highlighted as one of the principal drivers of intra-island allopatric speciation.

Based on the phylogenetic results, morphological features and distribution, five new monophyletic subgenera are described: Aridotrox subg. n., Belicarius subg. n., Bencomius subg. n., Canariotrox subg. n., and Purpuranius subg. n., totalling twenty subgenera in Laparocerus.


Back-colonisation, Bayesian inference, Canary Islands, dispersal, divergence rates, introgression, island evolution, Madeira, mitochondrial DNA, Moreiba Morocco, new subgenera, phylogeny, Selvagens Islands, speciation, weevils


O tempo e o ritmo do evento da Grande Oxidação

sexta-feira, fevereiro 17, 2017

Timing and tempo of the Great Oxidation Event

Ashley P. Gumsley a,1, Kevin R. Chamberlain b,c, Wouter Bleeker d, Ulf Söderlund a,e, Michiel O. de Kock f, Emilie R. Larsson a, and Andrey Bekker g,f

Author Affiliations

aDepartment of Geology, Lund University, Lund 223 62, Sweden;

bDepartment of Geology and Geophysics, University of Wyoming, Laramie, WY 82071;

cFaculty of Geology and Geography, Tomsk State University, Tomsk 634050, Russia;

dGeological Survey of Canada, Ottawa, ON K1A 0E8, Canada;

eDepartment of Geosciences, Swedish Museum of Natural History, Stockholm 104 05, Sweden;

fDepartment of Geology, University of Johannesburg, Auckland Park 2006, South Africa;

gDepartment of Earth Sciences, University of California, Riverside, CA 92521

Edited by Mark H. Thiemens, University of California, San Diego, La Jolla, CA, and approved December 27, 2016 (received for review June 11, 2016)


We present U-Pb ages for the extensive Ongeluk large igneous province, a large-scale magmatic event that took place near the equator in the Paleoproterozoic Transvaal basin of southern Africa at ca. 2,426 Ma. This magmatism also dates the oldest Paleoproterozoic global glaciation and the onset of significant atmospheric oxygenation. This result forces a significant reinterpretation of the iconic Transvaal basin stratigraphy and implies that the oxygenation involved several oscillations in oxygen levels across 10−5 present atmospheric levels before the irreversible oxygenation of the atmosphere. Data also indicate that the Paleoproterozoic glaciations and oxygenation were ushered in by assembly of a large continental mass, extensive magmatism, and continental migration to near-equatorial latitudes, mirroring a similar chain of events in the Neoproterozoic.


The first significant buildup in atmospheric oxygen, the Great Oxidation Event (GOE), began in the early Paleoproterozoic in association with global glaciations and continued until the end of the Lomagundi carbon isotope excursion ca. 2,060 Ma. The exact timing of and relationships among these events are debated because of poor age constraints and contradictory stratigraphic correlations. Here, we show that the first Paleoproterozoic global glaciation and the onset of the GOE occurred between ca. 2,460 and 2,426 Ma, ∼100 My earlier than previously estimated, based on an age of 2,426 ± 3 Ma for Ongeluk Formation magmatism from the Kaapvaal Craton of southern Africa. This age helps define a key paleomagnetic pole that positions the Kaapvaal Craton at equatorial latitudes of 11° ± 6° at this time. Furthermore, the rise of atmospheric oxygen was not monotonic, but was instead characterized by oscillations, which together with climatic instabilities may have continued over the next ∼200 My until ≤2,250–2,240 Ma. Ongeluk Formation volcanism at ca. 2,426 Ma was part of a large igneous province (LIP) and represents a waning stage in the emplacement of several temporally discrete LIPs across a large low-latitude continental landmass. These LIPs played critical, albeit complex, roles in the rise of oxygen and in both initiating and terminating global glaciations. This series of events invites comparison with the Neoproterozoic oxygen increase and Sturtian Snowball Earth glaciation, which accompanied emplacement of LIPs across supercontinent Rodinia, also positioned at low latitude.

Great Oxidation Event Snowball Earth Paleoproterozoic Kaapvaal Craton Transvaal Supergroup


1To whom correspondence should be addressed. 


Author contributions: A.P.G., U.S., and M.O.d.K. designed research; A.P.G., K.R.C., W.B., U.S., M.O.d.K., and E.R.L. performed research; K.R.C., W.B., U.S., and M.O.d.K. contributed new reagents/analytic tools; A.P.G., K.R.C., W.B., U.S., M.O.d.K., E.R.L., and A.B. analyzed data; and A.P.G., K.R.C., W.B., U.S., M.O.d.K., E.R.L., and A.B. wrote the paper.

The authors declare no conflict of interest.

This article is a PNAS Direct Submission.

This article contains supporting information online at

Freely available online through the PNAS open access option.


Segmentação caótica sincronizada e aceleração da química de superfície em microambientes hidrotermais prebióticos

Synchronized chaotic targeting and acceleration of surface chemistry in prebiotic hydrothermal microenvironments

Aashish Priye a, Yuncheng Yu a, Yassin A. Hassan b,c, and Victor M. Ugaz a,d,1

Author Affiliations

aArtie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843;

bDepartment of Mechanical Engineering, Texas A&M University, College Station, TX 77843;

cDepartment of Nuclear Engineering, Texas A&M University, College Station, TX 77843;

dDepartment of Biomedical Engineering, Texas A&M University, College Station, TX 77843

Edited by Howard A. Stone, Princeton University, Princeton, NJ, and approved December 19, 2016 (received for review August 3, 2016)

Fig. 1: Hydrothermal conveyor based on chaotic thermal convection.


We describe a physical mechanism capable of achieving simultaneous mixing and focused enrichment in hydrothermal pore microenvironments. Microscale chaotic advection established in response to a temperature gradient paradoxically promotes bulk homogenization of molecular species, while at the same time transporting species to discrete targeted locations on the bounding sidewalls where they become highly enriched. This process delivers an order of magnitude acceleration in surface reaction kinetics under conditions naturally found in subsea hydrothermal microenvironments, suggesting a new avenue to explain prebiotic emergence of macromolecules from dilute organic precursors—a key unanswered question in the origin of life on Earth and elsewhere.


Porous mineral formations near subsea alkaline hydrothermal vents embed microenvironments that make them potential hot spots for prebiotic biochemistry. But, synthesis of long-chain macromolecules needed to support higher-order functions in living systems (e.g., polypeptides, proteins, and nucleic acids) cannot occur without enrichment of chemical precursors before initiating polymerization, and identifying a suitable mechanism has become a key unanswered question in the origin of life. Here, we apply simulations and in situ experiments to show how 3D chaotic thermal convection—flows that naturally permeate hydrothermal pore networks—supplies a robust mechanism for focused accumulation at discrete targeted surface sites. This interfacial enrichment is synchronized with bulk homogenization of chemical species, yielding two distinct processes that are seemingly opposed yet synergistically combine to accelerate surface reaction kinetics by several orders of magnitude. Our results suggest that chaotic thermal convection may play a previously unappreciated role in mediating surface-catalyzed synthesis in the prebiotic milieu.

thermal convection prebiotic biochemistry hydrothermal vents chaos


1To whom correspondence should be addressed. Email:

Author contributions: A.P., Y.A.H., and V.M.U. designed research; A.P. and Y.Y. performed research; Y.A.H. contributed new reagents/analytic tools; A.P., Y.Y., and V.M.U. analyzed data; and A.P. and V.M.U. wrote the paper.

The authors declare no conflict of interest.

This article is a PNAS Direct Submission.

This article contains supporting information online at

Freely available online through the PNAS open access option.


Padrões de ontogenia das organelas: mero acaso, fortuita necessidade ou design inteligente?

quinta-feira, fevereiro 16, 2017

Patterns of organelle ontogeny through a cell cycle revealed by whole-cell reconstructions using 3D electron microscopy

Louise Hughes, Samantha Borrett, Katie Towers, Tobias Starborg, Sue Vaughan

J Cell Sci 2017 130: 637-647; doi: 10.1242/jcs.198887


The major mammalian bloodstream form of the African sleeping sickness parasite Trypanosoma brucei multiplies rapidly, and it is important to understand how these cells divide. Organelle inheritance involves complex spatiotemporal re-arrangements to ensure correct distribution to daughter cells. Here, serial block face scanning electron microscopy (SBF-SEM) was used to reconstruct whole individual cells at different stages of the cell cycle to give an unprecedented temporal, spatial and quantitative view of organelle division, inheritance and abscission in a eukaryotic cell. Extensive mitochondrial branching occurred only along the ventral surface of the parasite, but the mitochondria returned to a tubular form during cytokinesis. Fission of the mitochondrion occurred within the cytoplasmic bridge during the final stage of cell division, correlating with cell abscission. The nuclei were located underneath each flagellum at mitosis and the mitotic spindle was located along the ventral surface, further demonstrating the asymmetric arrangement of cell cleavage in trypanosomes. Finally, measurements demonstrated that multiple Golgi bodies were accurately positioned along the flagellum attachment zone, suggesting a mechanism for determining the location of Golgi bodies along each flagellum during the cell cycle.

FREE PDF GRATIS: Journal of Cell Science

Visualização de relance da actina

Actin visualization at a glance

Michael Melak, Matthias Plessner, Robert Grosse

J Cell Sci 2017 130: 525-530; doi: 10.1242/jcs.189068


Actin functions in a multitude of cellular processes owing to its ability to polymerize into filaments, which can be further organized into higher-order structures by an array of actin-binding and regulatory proteins. Therefore, research on actin and actin-related functions relies on the visualization of actin structures without interfering with the cycles of actin polymerization and depolymerization that underlie cellular actin dynamics. In this Cell Science at a Glance and the accompanying poster, we briefly evaluate the different techniques and approaches currently applied to analyze and visualize cellular actin structures, including in the nuclear compartment. Referring to the gold standard F-actin marker phalloidin to stain actin in fixed samples and tissues, we highlight methods for visualization of actin in living cells, which mostly apply the principle of genetically fusing fluorescent proteins to different actin-binding domains, such as LifeAct, utrophin and F-tractin, as well as anti-actin-nanobody technology. In addition, the compound SiR-actin and the expression of GFP–actin are also applicable for various types of live-cell analyses. Overall, the visualization of actin within a physiological context requires a careful choice of method, as well as a tight control of the amount or the expression level of a given detection probe in order to minimize its influence on endogenous actin dynamics.

FREE PDF GRATIS: Journal of Cell Science

Baba Brinkman e o rap do fato, Fato, FATO da evolução diante de nossos olhos

quarta-feira, fevereiro 15, 2017

Proteínas analisadas como nós virtuais: mero acaso, fortuita necessidade ou design inteligente?

terça-feira, fevereiro 14, 2017

Proteins analysed as virtual knots

Keith Alexander, Alexander J. Taylor & Mark R. Dennis

Scientific Reports 7, Article number: 42300 (2017)

Download Citation

Applied mathematics Biophysics Computational science Protein analysis

Received: 26 September 2016 Accepted: 05 January 2017 Published online: 13 February 2017

Figure 1: Protein backbone structures as open knotted space curves.


Long, flexible physical filaments are naturally tangled and knotted, from macroscopic string down to long-chain molecules. The existence of knotting in a filament naturally affects its configuration and properties, and may be very stable or disappear rapidly under manipulation and interaction. Knotting has been previously identified in protein backbone chains, for which these mechanical constraints are of fundamental importance to their molecular functionality, despite their being open curves in which the knots are not mathematically well defined; knotting can only be identified by closing the termini of the chain somehow. We introduce a new method for resolving knotting in open curves using virtual knots, which are a wider class of topological objects that do not require a classical closure and so naturally capture the topological ambiguity inherent in open curves. We describe the results of analysing proteins in the Protein Data Bank by this new scheme, recovering and extending previous knotting results, and identifying topological interest in some new cases. The statistics of virtual knots in protein chains are compared with those of open random walks and Hamiltonian subchains on cubic lattices, identifying a regime of open curves in which the virtual knotting description is likely to be important.


The authors are grateful to Benjamin Bode, Paula Booth, Neslihan Gügümcü, Lou Kauffman, Annela Seddon, Joanna Sulkowska and Stu Whittington for valuable discussions. This research was funded by the Leverhulme Trust Research Programme Grant No. RP2013-K-009, SPOCK: Scientific Properties of Complex Knots. Keith Alexander was funded by the Engineering and Physical Sciences Research Council. This work was carried out using the computational facilities of the Advanced Computing Research Centre, University of Bristol.

Author information


H H Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK

Keith Alexander, Alexander J. Taylor & Mark R. Dennis


K.A. carried out the protein analysis and virtual knotting routines. A.J.T. carried out the classical knot identification and random chain analysis, and suggested the original problem. M.R.D. directed the study and drafted the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Keith Alexander or Alexander J. Taylor or Mark R. Dennis.

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Contra Darwin, a biodiversidade é autocatalítica e as espécies "criam" nichos para outras espécies: design inteligente?

segunda-feira, fevereiro 13, 2017

Biodiversity is autocatalytic

Roberto Cazzolla Gatti a, Wim Hordijkb, Stuart Kauffman c, 

a Biological Diversity and Ecology Laboratory, Bio-Clim-Land Centre of Excellence, Tomsk State University (TSU), Tomsk, Russia

b Konrad Lorenz Institute for Evolution and Cognition Research, Klosterneuburg, Austria

c Institute for Systems Biology, Seattle, WA, USA

Received 14 October 2016, Revised 5 December 2016, Accepted 6 December 2016, Available online 3 January 2017


• Biodiversity can be considered a system of autocatalytic sets.

• This view offers a possible answer to the fundamental question of why so many species can coexist in the same ecosystem.

• We combine the “Biodiversity-related Niches Differentation Theory” (BNDT) with that of “Reflexively Autocatalytic and Food-generated Sets” (RAFs) to support our argument.


A central question about biodiversity is how so many species can coexist within the same ecosystem. The idea that ecological niches are critical for the maintenance of species diversity has received increasing support recently. However, a niche is often considered as something static, preconditioned, and unchanging. With the “Biodiversity-related Niches Differentiation Theory” (BNDT), we recently proposed that species themselves are the architects of biodiversity, by proportionally increasing the number of potentially available niches in a given ecosystem.

Along similar lines, but independently, the idea of viewing an ecosystem of interdependent species as an emergent autocatalytic set (a self-sustaining network of mutually “catalytic” entities) was suggested, where one (group of) species enables the existence of (i.e., creates niches for) other species.

Here, we show that biodiversity can indeed be considered a system of autocatalytic sets, and that this view offers a possible answer to the fundamental question of why so many species can coexist in the same ecosystem. In particular, we combine the two theories (BNDT and autocatalytic sets), and provide some simple but formal examples of how this would work.

Keywords Autocatalytic sets; Ecological niches; Biodiversity


Professores, pesquisadores e alunos de universidades públicas e privadas com acesso ao Portal de Periódicos CAPES/MEC podemler gratuitamente este artigo do Ecological Modelling e de mais 30.000 publicações científicas.



"Contrariando as crenças de Darwin, a biodiversidade, segundo o Dr. Cazzolla Gatti, não deriva “da guerra da natureza, da fome e da morte,” mas do poder da vida capacitar outra vida; não da guerra, mas da coexistência; não da competição, mas do evitar isso, ex.: da cooperação e facilitação, i.e., pela autocatálise." (PhysOrg)

Uau, como uma espécie pode facilitar nichos para outras espécies? Isso não é mais Darwin e sua natureza ensanguentada por dentes e garras, isso
 é teleologia, não é mais evolução cega e aleatória sem nenhum propósito, isso é design inteligente! 

Suporte de vida para células precursoras de neurônios: mero acaso, fortuita necessidade ou design inteligente?

miRNAs cooperate in apoptosis regulation during C. elegans development

Ryan Sherrard 1,3, Sebastian Luehr 1,3, Heinke Holzkamp 1, Katherine McJunkin 2, Nadin Memar 1 and Barbara Conradt 1

- Author Affiliations

1Center for Integrated Protein Science Munich – CIPSM, Department Biology II, Ludwig-Maximilians-University Munich, Planegg-Martinsried 82152, Germany;

2Program in Molecular Medicine, RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01606, USA

Corresponding authors:,

↵3 These authors contributed equally to this work.

Source/Fonte: Google Images


Programmed cell death occurs in a highly reproducible manner during Caenorhabditis elegans development. We demonstrate that, during embryogenesis, miR-35 and miR-58 bantam family microRNAs (miRNAs) cooperate to prevent the precocious death of mothers of cells programmed to die by repressing the gene egl-1, which encodes a proapoptotic BH3-only protein. In addition, we present evidence that repression of egl-1 is dependent on binding sites for miR-35 and miR-58 family miRNAs within the egl-1 3′ untranslated region (UTR), which affect both mRNA copy number and translation. Furthermore, using single-molecule RNA fluorescent in situ hybridization (smRNA FISH), we show that egl-1 is transcribed in the mother of a cell programmed to die and that miR-35 and miR-58 family miRNAs prevent this mother from dying by keeping the copy number of egl-1 mRNA below a critical threshold. Finally, miR-35 and miR-58 family miRNAs can also dampen the transcriptional boost of egl-1 that occurs specifically in a daughter cell that is programmed to die. We propose that miRNAs compensate for lineage-specific differences in egl-1 transcriptional activation, thus ensuring that EGL-1 activity reaches the threshold necessary to trigger death only in daughter cells that are programmed to die.

Keywords miRNA programmed cell death BH3-only development embryo C. elegans


Supplemental material is available for this article.

Article published online ahead of print. Article and publication date are online at

Freely available online through the Genes & Development Open Access option.

Received August 4, 2016 Accepted January 11, 2017.

© 2017 Sherrard et al.; Published by Cold Spring Harbor Laboratory Press

This article, published in Genes & Development, is available under a Creative Commons License (Attribution 4.0 International), as described at



A morte programada das células, conhecida como apoptose, é um processo fundamental e altamente regulado que ocorre em todos os organismos chamados de superiores. É um processo essencial para o desenvolvimento embrionário normal, durante o qual células supérfluas devem ser descartadas, mas de forma ordenada.

Mero acaso, fortuita necessidade ou 100% design inteligente?

Explosão em diversidade de especiação devido a hibridização antiga sem mutação e seleção natural

sábado, fevereiro 11, 2017

Ancient hybridization fuels rapid cichlid fish adaptive radiations

Joana I. Meier, David A. Marques, Salome Mwaiko, Catherine E. Wagner, Laurent Excoffier & Ole Seehausen

Nature Communications 8, Article number: 14363 (2017)

Download Citation

Adaptive radiation Evolutionary genetics Molecular evolution Phylogenetics

Received: 14 May 2016 Accepted: 20 December 2016 Published online: 10 February 2017


Understanding why some evolutionary lineages generate exceptionally high species diversity is an important goal in evolutionary biology. Haplochromine cichlid fishes of Africa’s Lake Victoria region encompass >700 diverse species that all evolved in the last 150,000 years. How this ‘Lake Victoria Region Superflock’ could evolve on such rapid timescales is an enduring question. Here, we demonstrate that hybridization between two divergent lineages facilitated this process by providing genetic variation that subsequently became recombined and sorted into many new species. Notably, the hybridization event generated exceptional allelic variation at an opsin gene known to be involved in adaptation and speciation. More generally, differentiation between new species is accentuated around variants that were fixed differences between the parental lineages, and that now appear in many new combinations in the radiation species. We conclude that hybridization between divergent lineages, when coincident with ecological opportunity, may facilitate rapid and extensive adaptive radiation.


We thank all collaborators who provided tissue samples over the years: Sigal Balshine-Earn (McMaster), Roger Bills (SAIAB), Julia Day (UCL), Yves Fermon (Paris), John Friel (CUMV), Martin Genner (U Bristol), Sylvain Piry (Paris), Lukas Rüber (Bern Natural History Museum), Walter Salzburger (U Basel), Uli Schliewen (Zoologische Staatssammlung Munich), Erwin Schraml (Augsburg), Jos Snoeks (Africa Museum Tervuren), Melanie Stiassny (AMNH), George Turner (U Bangor), Sylvester Wandera (NAFIRI; Uganda) and Marco Welss (Kressberg). We also thank Matt McGee for help with DNA extraction, Keith Harshman of the Lausanne Genomic Technologies Facility and Cord Drogemüller, Tosso Leeb, Muriel Fragnière and Michèle Ackermann of the NGS platform of the University of Bern for Illumina sequencing support, Aria Minder and Stefan Zoller of the Genetic Diversity Center (GDC) at ETH Zürich and Irene Keller of the Interfaculty Bioinformatics Unit at the University of Bern for lab and bioinformatics support and discussion, and Andy Cohen for comments on the paleogeographic maps. This research was supported by the Swiss National Science Foundation grant PDFMP3 134657 to O.S. and L.E.

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Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, 3012 Bern, Switzerland

Joana I. Meier, David A. Marques, Salome Mwaiko, Catherine E. Wagner & Ole Seehausen

Department of Fish Ecology and Evolution, Centre for Ecology, Evolution & Biogeochemistry, Eawag: Swiss Federal Institute of Aquatic Science and Technology, 6047 Kastanienbaum, Switzerland

Joana I. Meier, David A. Marques, Salome Mwaiko, Catherine E. Wagner & Ole Seehausen

Computational and Molecular Population Genetics Lab, Institute of Ecology and Evolution, University of Bern, 3012 Bern, Switzerland

Joana I. Meier, David A. Marques & Laurent Excoffier

Biodiversity Institute & Department of Botany, University of Wyoming, Laramie Wyoming 82071, USA

Catherine E. Wagner

Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland

Laurent Excoffier


O.S., J.I.M. and C.E.W. designed the study; O.S. gathered and identified the cichlid samples; J.I.M., S.M. and D.A.M. performed the lab work (DNA extraction, mtDNA and LWS sequencing and RAD library preparation); J.I.M. conducted the analyses, with assistance from O.S., C.E.W., D.A.M. and L.E.; J.I.M. prepared the manuscript together with O.S. and C.E.W. and L.E. and D.A.M. contributed to writing.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Ole Seehausen.

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Procure no artigo e não encontrá menção de mutação e/ou seleção natural como processos evolucionários. Darwin, isso é uma afronta!!! A hibridização é meramente o compartilhar de informação genética existente; ela não cria nada novo - os peixes ciclídeos continuaram peixes ciclídeos.

Genética da macroevolução das aves

quarta-feira, fevereiro 08, 2017

Functional roles of Aves class-specific cis-regulatory elements on macroevolution of bird-specific features

Ryohei Seki, Cai Li, Qi Fang, Shinichi Hayashi, Shiro Egawa, Jiang Hu, Luohao Xu, Hailin Pan, Mao Kondo, Tomohiko Sato, Haruka Matsubara, Namiko Kamiyama, Keiichi Kitajima, Daisuke Saito, Yang Liu, M. Thomas P. Gilbert, Qi Zhou, Xing Xu, Toshihiko Shiroishi, Naoki Irie, Koji Tamura & Guojie Zhang

Nature Communications 8, Article number: 14229 (2017)

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Evolutionary developmental biology Gene regulation Genomics

Received: 25 April 2016 Accepted: 12 December 2016 Published online: 06 February 2017

Figure 6: Sim1 and flight feather evolution.


Unlike microevolutionary processes, little is known about the genetic basis of macroevolutionary processes. One of these magnificent examples is the transition from non-avian dinosaurs to birds that has created numerous evolutionary innovations such as self-powered flight and its associated wings with flight feathers. By analysing 48 bird genomes, we identified millions of avian-specific highly conserved elements (ASHCEs) that predominantly (>99%) reside in non-coding regions. Many ASHCEs show differential histone modifications that may participate in regulation of limb development. Comparative embryonic gene expression analyses across tetrapod species suggest ASHCE-associated genes have unique roles in developing avian limbs. In particular, we demonstrate how the ASHCE driven avian-specific expression of gene Sim1 driven by ASHCE may be associated with the evolution and development of flight feathers. Together, these findings demonstrate regulatory roles of ASHCEs in the creation of avian-specific traits, and further highlight the importance of cis-regulatory rewiring during macroevolutionary changes.


We thank Professor Jon Fjeldså of the University of Copenhagen for valuable comments. This project was supported by Strategic Priority Research Program of the Chinese Academy of Sciences (XDB13000000) and Lundbeckfonden grant R190-2014-2827. K.T. was supported by JSPS KAKENHI Grant (JP15H04374), grant from The Naito Foundation, and Next Generation World-Leading Researchers from the Cabinet Office, Government of Japan (LS007). R.S., S.E. and H.M. are JSPS Research Fellows (JSPS KAKENHI Grant Numbers JP14J07050 (R.S.), JP15J06859 (S.E.), JP15J06385 (H.M.)). C.L. was partially supported by Lundbeckfonden grant R52-5062 to M.T.P.G.). N.I. was partially supported by Platform Project for Supporting in Drug Discovery and Life Science Research Platform for Dynamic Approaches to Living System from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) and Japan Agency for Medical Research and Development (AMED). Photographs of the adult Cochin bantam and Brahmas bantam and their fertilized eggs were provided by the National BioResource Project (NBRP) Chicken/Quail of the MEXT, Japan.

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Author notes

Ryohei Seki & Cai Li

These authors contributed equally to this work


Mammalian Genetics Laboratory, Genetic Strains Research Center, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, Japan

Ryohei Seki & Toshihiko Shiroishi

Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama 6-3, Aoba-ku, Sendai 980-8578, Japan

Ryohei Seki, Shinichi Hayashi, Shiro Egawa, Mao Kondo, Tomohiko Sato, Haruka Matsubara, Namiko Kamiyama, Keiichi Kitajima, Daisuke Saito & Koji Tamura

State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China

Cai Li, Qi Fang, Jiang Hu, Luohao Xu, Hailin Pan, Yang Liu & Guojie Zhang

China National GeneBank, BGI-Shenzhen, Shenzhen 518083, China

Cai Li, Qi Fang, Hailin Pan & Guojie Zhang

Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Copenhagen 1350, Denmark

Cai Li & M. Thomas P. Gilbert

Department of Genetics, Cell Biology and Development, University of Minnesota, 321 Church Street SE, Minneapolis, Minnesota 55455, USA

Shinichi Hayashi

Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, Aobayama 6-3, Aoba-ku, Sendai 980-8578, Japan

Daisuke Saito

Norwegian University of Science and Technology, University Museum, N-7491 Trondheim, Norway

M. Thomas P. Gilbert

Department of Integrative Biology University of California, Berkeley, California 94720, USA

Qi Zhou

Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China

Xing Xu

Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan

Naoki Irie

Centre for Social Evolution, Department of Biology, Universitetsparken 15, University of Copenhagen, Copenhagen 2100, Denmark

Guojie Zhang


G.Z., K.T. and N.I. designed the study. C.L., Q.F., J.H., L.X., H.P. and Y.L. conducted the computational analyses. R.S., S.H., S.E., M.K., T.S., H.M., N.K., K.K. and D.S. conducted the wet-lab experiments and analysed the data. G.Z., K.T., N.I., X.X., R.S. and C.L. wrote the manuscript. M.T.P.G., Q.Z. and T.S provided critical comments for improving the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Naoki Irie or Koji Tamura or Guojie Zhang.