Exaptation traits for megafaunal Mutualisms as a factor in plant domestication

Megafaunal extinctions are recurring events that cause evolutionary ripples, as cascades of secondary extinctions and shifting selective pressures reshape ecosystems. Megafaunal browsers and grazers are major ecosystem engineers, they: keep woody vegetation suppressed; are nitrogen cyclers; and serve as seed dispersers. Most angiosperms possess sets of physiological traits that allow for the fixation of mutualisms with megafauna; some of these traits appear to serve as exaptation (preadaptation) features for farming. As an easily recognized example, fleshy fruits are, an exaptation to agriculture, as they evolved to recruit a non-human disperser. We hypothesize that the traits of rapid annual growth, self-compatibility, heavy investment in reproduction, high plasticity (wide reaction norms), and rapid evolvability were part of an adaptive syndrome for megafaunal seed dispersal. We review the evolutionary importance that megafauna had for crop and weed progenitors and discuss possible ramifications of their extinction on: (1) seed dispersal; (2) population dynamics; and (3) habitat loss. Humans replaced some of the ecological services that had been lost as a result of late Quaternary extinctions and drove rapid evolutionary change resulting in domestication.Introduction Lost Seed-Dispersal Services - Small-Seeded Grains and Legumes - Large Fleshy Fruiting Plants Loss of Herbivory and Disturbance Regimes Plant Domestication - Exaptation Traits Supporting Domestication Anthropogenic Ecosystem Service

A Journey to the West: The Ancient Dispersal of Rice Out of East Asia

Rice is one of the most culturally valued and widely grown crops in the world today, and extensive research over the past decade has clarified much of the narrative of its domestication and early spread across East and South Asia. However, the timing and routes of its dispersal into West Asia and Europe, through which rice eventually became an important ingredient in global cuisines, has remained less clear. In this article, we discuss the piecemeal, but growing, archaeobotanical data for rice in West Asia. We also integrate written sources, linguistic data, and ethnohistoric analogies, in order to better understand the adoption of rice outside its regions of origin. The human-mediated westward spread of rice proceeded gradually, while its social standing and culinary uses repeatedly changing over time and place. Rice was present in West Asia and Europe by the tail end of the first millennium BC, but did not become a significant crop in West Asia until the past few centuries. Complementary historical, linguistic, and archaeobotanical data illustrate two separate and roughly contemporaneous routes of westward dispersal, one along the South Asian coast and the other through Silk Road trade. By better understanding the adoption of this water-demanding crop in the arid regions of West Asia, we explore an important chapter in human adaptation and agricultural decision making

Prehistoric agricultural decision making in the western Himalayas: ecological and social variables

The high-altitude landscape of western Tibet is one of the most extreme environments in which humans have managed to introduce crop cultivation. To date, only sparse palaeoeconomic data have been reported from this region. The authors present archaeobotanical evidence from five sites (dating from the late first millennium BC and the early first millennium AD) located in the cold-arid landscape of western Tibet. The data indicate that barley was widely grown in this region by c. 400 BC but probably fulfilled differing roles within local ecological constraints on cultivation. Additionally, larger sites are characterised by more diverse crop assemblages than smaller sites, suggesting a role for social diversity in the development of high-altitude agriculture.Introduction Excavations at high-elevation sites in western Tibet Archaeobotanical analysis Discussion - Ecologically distinct economic systems - Highlands above the limits of farming (>4600m asl) - Barley cultivation in the higher river valleys (>4000m asl) - Diverse agricultural systems in the lower river valleys - Agricultural choices among sites of different sizes - Barley cultivation at small sites - Crop diversity at large sites Conclusio

Seeing the wood for the trees: active human–environmental interactions in arid northwestern China

Due largely to demographic growth, agricultural populations during the Holocene became increasingly more impactful ecosystem engineers. Multidisciplinary research has revealed a deep history of human–environmental dynamics; however, these pre-modern anthropogenic ecosystem transformations and cultural adaptions are still poorly understood. Here, we synthesis anthracological data to explore the complex array of human–environmental interactions in the regions of the prehistoric Silk Road. Our results suggest that these ancient humans were not passively impacted by environmental change; rather, they culturally adapted to, and in turn altered, arid ecosystems. Underpinned by the establishment of complex agricultural systems on the western Loess Plateau, people may have started to manage chestnut trees, likely through conservation of economically significant species, as early as 4600 BP. Since ca. 3500 BP, with the appearance of high-yielding wheat and barley farming in Xinjiang and the Hexi Corridor, people appear to have been cultivating Prunus and Morus trees. We also argue that people were transporting preferred coniferous woods over long distances to meet the need for fuel and timber. After 2500 BP, people in our study area were making conscious selections between wood types for craft production and were also clearly cultivating a wide range of long-generation perennials, showing a remarkable traditional knowledge tied into the arid environment. At the same time, the data suggest that there was significant deforestation throughout the chronology of occupation, including a rapid decline of slow-growing spruce forests and riparian woodlands across northwestern China. The wood charcoal dataset is publicly available at https://doi.org/10.5281/zenodo.8158277 (Shen et al., 2023).</p

An imagined past?: Nomadic narratives in Central Asian archaeology

Nomads, or highly specialized mobile pastoralists, are prominent features in Central Asian archaeology, and they are often depicted in direct conflict with neighboring sedentary peoples. However, new archaeological findings are showing that the people who many scholars have called nomads engaged in a mixed economic system of farming and herding. Additionally, not all of these peoples were as mobile as previously assumed, and current data suggest that a portion of these purported mobile populations remained sedentary for much or all of the year, with localized ecological factors directing economic choices. In this article, we pull together nine complementary lines of evidence from the second through the first millennia BC to illustrate that in eastern Central Asia, a complex economy existed. While many scholars working in Eurasian archaeology now acknowledge how dynamic paleoeconomies were, broader arguments are still tied into assumptions regarding specialized economies. The formation of empires or polities, changes in social orders, greater political hierarchy, craft specialization?notably, advanced metallurgy?mobility and migration, social relations, and exchange have all been central to the often circular arguments made concerning so-called nomads in ancient Central Asia. The new interpretations of mixed and complex economies more effectively situate Central Asia into a broader global study of food production and social complexity.- Geographic Focus of This Discussion - The Nomadic Bias Macrobotanical Data Microbotanical Data Isotope Studies Ethnographic and Ethnohistoric Analogies Sedentary Occupation Structures - Villages and Fortified Sites - Farmsteads (Homesteads) Material Culture Evidence for Economy Nonportable Material Culture Zooarchaeology Written Sources Discussion - Two Millennia of Political Agendas - Arguments Used to Support Nomadic Models Conclusion Comments Repl

Morphotype broadening of the grapevine (Vitis vinifera L.) from Oxus civilization 4000 BP, Central Asia

The region of Transoxiana underwent an early agricultural-demographic transition leading to the earliest proto-urban centers in Central Asia. The agronomic details of this cultural shift are still poorly studied, especially regarding the role that long-generation perennials, such as grapes, played in the cultivation system. In this paper, we present directly dated remains of grape pips from the early urban centers of Sapalli and Djarkutan, in south Uzbekistan. We also present linear morphometric data, which illustrate a considerable range of variation under cultivation that we divide into four distinct morphotypes according to pip shape. While some of the pips in these two assemblages morphologically fall within the range of wild forms, others more closely resemble modern domesticated populations. Most of the specimens measure along a gradient between the two poles, showing a mixed combination of domesticated and wild features. We also point out that the seeds recovered from the Djarkutan temple were, on average, larger and contained more affinity towards domesticated forms than those from domestic contexts. The potential preference of morphotypes seems to suggest that there were recognized different varieties that local cultivators might aware and possibly propagating asexually.- Dating of archaeobotanical samples. - Morphotyping the archaeological grape pips. - Grape morphological diversity and human selection in Bronze Age Central Asia. - Grape seed morphology and early horticulture. - Conclusions. - Method

Antimicrobial activity of a library of thioxanthones and their potential as efflux pump inhibitors

The overexpression of efflux pumps is one of the causes of multidrug resistance, which leads to the inefficacy of drugs. This plays a pivotal role in antimicrobial resistance, and the most notable pumps are the AcrAB-TolC system (AcrB belongs to the resistance-nodulation-division family) and the NorA, from the major facilitator superfamily. In bacteria, these structures can also favor virulence and adaptation mechanisms, such as quorum-sensing and the formation of biofilm. In this study, the design and synthesis of a library of thioxanthones as potential efflux pump inhib-itors are described. The thioxanthone derivatives were investigated for their antibacterial activity and inhibition of efflux pumps, biofilm formation, and quorum-sensing. The compounds were also studied for their potential to interact with P-glycoprotein (P-gp, ABCB1), an efflux pump present in mammalian cells, and for their cytotoxicity in both mouse fibroblasts and human Caco-2 cells. The results concerning the real-time ethidium bromide accumulation may suggest a potential bacterial efflux pump inhibition, which has not yet been reported for thioxanthones. Moreover, in vitro studies in human cells demonstrated a lack of cytotoxicity for concentrations up to 20 µM in Caco-2 cells, with some derivatives also showing potential for P-gp modulation.This research was supported by national funds through FCT (Foundation for Science and Technology) within the scope of UIDB/04423/2020, UIDP/04423/2020 (Group of Natural Products and Medicinal Chemistry-CIIMAR), and under the project PTDC/SAU-PUB/28736/2017 (reference POCI-01–0145-FEDER-028736), co-financed by COMPETE 2020, Portugal 2020 and the European Union through the ERDF and by FCT through national funds and structured program of R&D&I ATLANTIDA (NORTE-01-0145-FEDER-000040), supported by NORTE2020, through ERDF, and CHIRALBIO ACTIVE-PI-3RL-IINFACTS-2019

Manejo de buva em áreas cultivadas com milho safrinha e aveia.

A infestação de buva (Conyza spp) tem aumentado significativamente nas áreas de produção do sistema soja-trigo-milho especialmente nos estados do Paraná e Rio Grande do Sul. Foram conduzidos dois experimentos na safra 2009/2010 em uma propriedade rural do município de Campo Mourão, PR, com o objetivo de testar alternativas para o controle químico da buva, utilizando-se diferentes produtos e doses, aplicados na dessecação em pré-semeadura da soja, cultivada em áreas contíguas cobertas por palha de milho e de aveia. Foram aplicadas combinações de glifosato com diclosulan, flumioxazin, clorimuron-ethyl, imazetapyr, 2,4-0, paraquat+diuron e saflufenasil. É sabido que existe uma relação entre o tipo de cobertura e o tamanho das plantas de buva, o que pode influenciar no controle por ocasião da aplicação e que plantas menores são melhor controladas do que plantas mais desenvolvidas. Neste trabalho, 64% das plantas de buva na área com aveia estavam com. menos de 10 cm de altura e 36% entre 10 a 20 cm. Já na área com cobertura de milho safrinha apenas 20% das plantas estavam com menos de 10cm de altura, 56% entre 10 a 20 cm e outros 20% com mais de 20cm de altura. Embora não seja possível comparar os dois experimentos entre si, ficou evidente o melhor controle obtido pela maioria dos tratamentos quando aplicados sobre a cobertura de aveia, o que pode ser explicado pela diferença de tamanho das plantas por ocasião das aplicações. A combinação de glifosato com 2,4-0 ou herbicidas que possuem ação residual, complementada com aplicação sequencial que envolve um produto de contato tem mostrado ser uma importante forma de manejo químico para o controle da buva

Interferência da buva em áreas cultivadas com soja.

O aumento de incidência de buva nas áreas de cultivo da soja era previsto como consequência da adoção do plantio direto e das características inerentes a essa planta daninha, como o tamanho de suas sementes, a prolificidade, a dispersão pelo vento e a germinação na superfície do solo. A buva é uma planta nativa das Américas e sempre esteve presente na relação das principais espécies invasoras no Brasil. Nos últimos anos esta espécie passou a ser uma das principais infestantes das áreas de cultivo do sistema soja-milho-trigo na região sul do Brasil. O objetivo do trabalho foi analisar a interferência causada pelas plantas de buva na cultura da soja. Três experimentos foram conduzidos na safra 2008/2009 e um na safra 2009/2010, todos em áreas comercias escolhidas aleatoriamente e cujo manejo da área e do cultivo havia sido feito pelo produtor. A metodologia constou da determinação do rendimento de grãos em relação a diferentes níveis de infestação da buva. Paralelamente, foram coletadas amostras de soja provenientes do graneleiro de uma colheitadeira que operava na área, para a classificação dos grãos quanto ao teor de umidade e impureza. Os resultados indicam que a interferência da buva cultura da soja não se limita a reduções do rendimento de grãos, cujos valores em média apresentaram perdas que variaram de 1174Kg ha-' a 1469 Kg há-' nos maiores níveis de infestação, o que correspondeu a até 48% de perdas em relação a área sem infestação. Nos níveis mais baixos de infestação as perdas relativas de rendimento em comparação com as áreas sempre limpas variaram no diferentes experimentos de 2% a quase 5%. A presença da buva. interferiu também na classificação comercial da soja, chegando a aumentar a umidade dos grão em percentuais que variaram de 2 a 7% e a impureza de 1,8% a mais de 6% dependendo do nível de infestação