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In biology there is an awakening tendency to inquire beyond the definitions which mechanism and vitalism have given for 'life' and 'organism,' and to define anew the kind of Being which belongs to the living as such
 

Martin Heidegger

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 Via: Peter Turchin

Achieving similar root microbiota composition in neighbouring plants through airborne signalling   

Kong et al., 2021

The ability to recognize and respond to environmental signals is essential for plants. In response to environmental changes, the status of a plant is transmitted to other plants in the form of signals such as volatiles. Root-associated bacteria trigger the release of plant volatile organic compounds (VOCs). However, the impact of VOCs on the rhizosphere microbial community of neighbouring plants is not well understood. Here, we investigated the effect of VOCs on the rhizosphere microbial community of tomato plants inoculated with a plant growth-promoting rhizobacterium Bacillus amyloliquefaciens strain GB03 and that of their neighbouring plants. Interestingly, high similarity (up to 69%) was detected in the rhizosphere microbial communities of the inoculated and neighbouring plants. Leaves of the tomato plant treated with strain GB03-released β-caryophyllene as a signature VOC, which elicited the release of a large amount of salicylic acid (SA) in the root exudates of a neighbouring tomato seedling. The exposure of tomato leaves to β-caryophyllene resulted in the secretion of SA from the root. Our results demonstrate for the first time that the composition of the rhizosphere microbiota in surrounding plants is synchronized through aerial signals from plants.

 

The reaction of surrounding plants that have undergone volatile signalling changes in the composition of SA in plant root secretions, affecting microorganisms and stimulating specific microbial dominance, similar to the microbial community of emitter plants.

https://go.nature.com/3cccvp6

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Survival of the Systems 

 Lenton et al., 2021

Recent theoretical progress highlights that natural selection can occur based solely on differential persistence of biological entities, without the need for conventional replication.

This calls for a reconsideration of how ecosystems and social (-ecological) systems can evolve, based on identifying system-level properties that affect their persistence.

Feedback cycles have irreducible properties arising from the interactions of unrelated components, and are critical to determining ecosystem and social system persistence.

Self-perpetuating feedbacks involving the acquisition and recycling of resources, alteration of local environmental conditions, and amplification of disturbance factors, enhance ecosystem and social system spread and persistence.

Cycles built from the by-products of traits, naturally selected at lower levels, avoid conflict between levels and types of selection.

Since Darwin, individuals and more recently genes, have been the focus of evolutionary thinking. The idea that selection operates on nonreproducing, higher-level systems including ecosystems or societies, has met with scepticism. But research emphasising that natural selection can be based solely on differential persistence invites reconsideration of their evolution. Self-perpetuating feedback cycles involving biotic as well as abiotic components are critical to determining persistence. Evolution of autocatalytic networks of molecules is well studied, but the principles hold for any ‘self-perpetuating’ system. Ecosystem examples include coral reefs, rainforests, and savannahs. Societal examples include agricultural systems, dominant belief systems, and economies. Persistence-based selection of feedbacks can help us understand how ecological and societal systems survive or fail in a changing world.

https://cutt.ly/GjL3lUl

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What we observe is not nature in itself but nature exposed to our method of questioning

Werner Heisenberg

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Genetic correlations and ecological networks shape coevolving mutualisms 

Assis et al., 2020

Ecological interactions shape the evolution of multiple species traits in populations. These traits are often linked to each other through genetic correlations, affecting how each trait evolves through selection imposed by interacting partners. Here, we integrate quantitative genetics, coevolutionary theory and network science to explore how trait correlations affect the coevolution of mutualistic species not only in pairs of species but also in species‐rich networks across space. We show that genetic correlations may determine the pace of coevolutionary change, affect species abundances and fuel divergence among populations of the same species. However, this trait divergence promoted by genetic correlations is partially buffered by the nested structure of species‐rich mutualisms. Our study, therefore, highlights how coevolution and its ecological consequences may result from conflicting processes at different levels of organisation, ranging from genes to communities.

https://doi.org/10.1111/ele.13605

 Fragile Harvest (¡¡¡1986!!!)

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There is a world beyond ours, a world that is far away, nearby and invisible.

 

Maria Sabina

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Limits and constraints to crop domestication 

Markus G. Stetter, 2020

 

The domestication of plants and animals was one of the most significant changes in human history. A managed cultivation of crops allowed a sedentary lifestyle and the division of work, which freed capacities to develop modern societies.

The change from a wild plant to a crop required substantial morphological and physiological adaptation. Crops with similar uses display similar trait changes, which are summarized in the domestication syndrome (Hammer, 1984). For grain crops, loss of seed shattering, increased seed size, and loss of seed dormancy are major domestication traits (Fig. 1). Crops that combine most domestication traits and consequently are well adapted to agroecological environments can be considered fully domesticated, while those that only display a few crop traits may be considered as incompletely domesticated. Although hundreds of grain crops have been cultivated by humans for millennia, most plants show only few of the domestication traits rather than the full syndrome (Meyer et al., 2012). Consequently, only a small fraction of the over 2000 crops that we know today are fully domesticated. Even crops that were of high importance for early cultures display only a minor fraction of the domestication syndrome. Studying the signals of incomplete crop domestication in minor crops could reveal the limits and constraints of crop selection and unlock the potential of novel crops for sustainable food production. 

Here, I review the evidence of potential genetic limits and constraints that altered the path of crop domestication. I present potential genetic features that might have favored the rapid full domestication of certain plant species and hindered the complete domestication of others. My examples and conclusions are mostly based on annual grain crops because their domestication syndrome is well defined and overlapping. Yet, most of the concepts also hold true for tuber, root, fruit, and vegetable crops, although more domestication traits are based on human preferences (i.e., flavor and color) for these crops.

 

Paths to full domestication. The genetic makeup of the ancestors of major crops allowed them to progress straight on the path to domestication. Other plant species had to take detours on the path and are consequently less domesticated today. The detours taken differ among crops, and constraints are not independent. The order and number of detours are specific to each crop.

 

https://bit.ly/3gQ6638

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Agricultural land use disrupts biodiversity mediation of virus infections in wild plant populations 

Hanna Susi and Anna‐Liisa Laine

• Human alteration of natural habitats may change the processes governing species interactions in wild communities. Wild populations are increasingly impacted by agricultural intensification, yet it is unknown whether this alters biodiversity mediation of disease dynamics.
• We investigated the association between plant diversity (species richness, diversity) and infection risk (virus richness, prevalence) in populations of Plantago lanceolata in natural landscapes as well as those occurring at the edges of cultivated fields. Altogether 27 P. lanceolata populations were surveyed for population characteristics and sampled for PCR detection of five recently characterized viruses.
• We find that plant species richness and diversity correlated negatively with virus infection prevalence. Virus species richness declined with increasing plant diversity and richness in natural populations while in agricultural edge populations’ species richness was moderately higher, and not associated with plant richness. This difference was not explained by changes in host richness between these two habitats, suggesting potential pathogen spill‐over and increased transmission of viruses across the agro‐ecological interface. Host population connectivity significantly decreased virus infection prevalence.
• We conclude that human use of landscapes may change the ecological laws by which natural communities are formed with far reaching implications for ecosystem functioning and disease.

https://bit.ly/3obMmtz

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Conuco: Fruto del árbol Kalivirnae

Diego Griffon, 2020

El conuco es, sin lugar a dudas, el sistema de agricultura familiar ancestral más importante de Venezuela. Este puede ser caracterizado, en términos ecológicos, como un sistema de agricultura de perturbación y sucesión, es decir, un sistema que se origina en la perturbación parcial de un ecosistema (típicamente un bosque), en el que luego se obtienen cosechas variadas a partir de cada uno de los arreglos de especies que se dan a lo largo de la sucesión ecológica —antrópicamente intervenida— hasta alcanzar de nuevo un estado similar al original (preperturbación). Es importante hacer esta definición, porque erróneamente se ha circunscrito el conuco a los primeros años de los sistemas denominados de roza-tumba-quema. Esto es, como se mostrará más adelante, en primer lugar, una profunda subestimación de la complejidad del sistema, y en segundo, una evidente manifestación de desdén y menosprecio por esta forma particular de agricultura. También hay que mencionar que existen conucos que no se corresponden con esta definición, sistemas más simples (i.e., no incluyen la sucesión ecológica), que no son el objeto central de estudio en este trabajo. 

https://bit.ly/2L1oBFP

 

 

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