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Ce qui est simple est toujours faux. Ce qui ne l'est pas est inutilisable.   

Paul Valéry. 1942. Mauvaises pensées et autres. 

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A cornucopia of color

Via: @nomacph

Coexistence in diverse communities with higher-order interactions    

Gibbs et al., preprint.

A central assumption in most ecological models is that the interactions in a community operate only between pairs of species. However, the interaction between two species may be fundamentally changed by the presence of others. Although interactions among three or more species, called higher-order interactions, have the potential to modify our theoretical understanding of coexistence, ecologists lack clear expectations for how these interactions shape community structure. Here, we analytically predict and numerically confirm how the variability and strength of higher-order interactions affect species coexistence. We found that, as higher-order interaction strengths become more variable across species, fewer species coexist, echoing the behavior of pairwise models. If inter-specific higher-order interactions become too harmful relative to self-regulation, coexistence was destabilized, but coexistence was also lost when these interactions were too weak and mutualistic effects became prevalent. Last, we showed that more species rich communities structured by higher-order interactions lose species more readily than their species poor counterparts, generalizing classic results for community stability. Our work provides needed theoretical expectation for how higher-order interactions impact species coexistence in diverse communities.

https://www.biorxiv.org/content/10.1101/2022.03.04.483022v1

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On Naval Timber and Arboriculture

Patrick Matthew

Published in 1831, it is noted for parts of it appendices in which Matthew discusses natural selection, 28 years prior to Charles Darwin's publication of On the Origin of Species.

https://en.wikipedia.org/wiki/On_Naval_Timber_and_Arboriculture

Patrick Matthew (1790 –  1874) 

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Finally out of reach- 

No bondage, no dependency. 

How calm the ocean, 

Towering the void. 

 

Tessho

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New Light on the Dawn: a new perspective on the Neolithic Revolution in Southwest Asia

Trevor Watkins

 

 Jan Mankes

 

GÖBEKLI TEPE REVEALED: What we know in 2022 

Dr. Lee Clare

Fingerprints of High-Dimensional Coexistence in Complex Ecosystems  

Barbier et al., 2021.

The coexistence of many competing species in an ecological community is a long-standing theoretical and empirical puzzle. Classic approaches in ecology assume that species fitness and interactions in a given environment are mainly driven by a few essential species traits, and coexistence can be explained by trade-offs between these traits. The apparent diversity of species is then summarized by their positions (“ecological niches”) in a low-dimensional trait space. Yet, in a complex community, any particular set of traits and trade-offs is unlikely to encompass the full organization of the community. A diametrically opposite approach assumes that species interactions are disordered, i.e., essentially random, as might arise when many species traits combine in complex ways. This approach is appealing theoretically, and can lead to novel emergent phenomena, fundamentally different from the picture painted by low-dimensional theories. Nonetheless, fully disordered interactions are incompatible with many-species coexistence, and neither disorder nor its dynamical consequences have received direct empirical support so far. Here we ask what happens when random species interactions are minimally constrained by coexistence. We show theoretically that this leads to testable predictions. Species interactions remain highly disordered, yet with a “diffuse” statistical structure: interaction strengths are biased so that successful competitors subtly favor each other, and correlated so that competitors partition their impacts on other species. We provide strong empirical evidence for this pattern, in data from grassland biodiversity experiments that match our predictions quantitatively. This is a first-of-a-kind test of disorder on empirically measured interactions, and unique evidence that species interactions and coexistence emerge from an underlying high-dimensional space of ecological traits. Our findings provide a new null model for inferring interaction networks with minimal prior information and a set of empirical fingerprints that support a statistical physics-inspired approach of complex ecosystems.

https://bit.ly/32kXWN4

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Pájaros

Eugenio Montejo

Oigo los pájaros afuera,

otros, no los de ayer que ya perdimos,

los nuevos silbos inocentes.

Y no sé si son pájaros,

si alguien que ya no soy los sigue oyendo

a media vida bajo el sol de la tierra.

Quizás es el deseo de retener su voz salvaje

en la mitad de la estación

antes que de los árboles se alejen.

 

Alguien que he sido o soy, no sé,

oye o recuerda,

si hay algo real dentro de mí son ellos,

más que yo mismo, más que el sol afuera,

si es musical la fuerza que hace girar el mundo,

no ha habido nunca sino pájaros,

el canto de los pájaros

que nos trae y nos lleva.

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