scholarly journals Genome-wide footprints in the carob tree (Ceratonia siliqua) unveil a new domestication pattern of fruit trees in the Mediterranean

2021 ◽  
Author(s):  
Alex Baumel ◽  
Gonzalo Nieto Feliner ◽  
Frederic Medail ◽  
Stefano La Malfa ◽  
Mario Diguardo ◽  
...  
Keyword(s):  
Eastern Mediterranean ◽  
Ex Situ ◽  
Plant Domestication ◽  
Mediterranean Forests ◽  
Migration Routes ◽  
Long Distance ◽  
Genome Wide ◽  
Western Morocco ◽  
Carob Tree ◽  
The Mediterranean

Intense research efforts on phylogeography over the last two decades uncovered major biogeographical trends and renewed our understandings of plant domestication in the Mediterranean. We aim to investigate the evolutionary history and the origin of domestication of the carob tree that has been cultivated for millennia for food and fodder. We used >1000 microsatellite genotypes to identify carob evolutionary units (CEUs) based on genetic diversity structure and geography. We investigated genome-wide diversity and evolutionary patterns of the CEUs with 3557 SNPs generated by restriction-site associated DNA sequencing (RADseq). The 56 populations sampled across the Mediterranean basin, classified as natural, semi-natural or cultivated, were examined. Although, RADseq data are consistent with previous studies identifying a strong West-to-East genetic structure and considerable admixture in some geographic parts, we reconstructed a new phylogeographic scenario with two migration routes occurring from a single refugium likely located in South-Western Morocco. Our results do not favour the regionally bound or single origin of domestication. Indeed, our findings support a cultivation model of locally selected wild genotypes, albeit punctuated by long-distance westward dispersals of domesticated varieties by humans, concomitant with major cultural waves by Romans and Arabs in the regions of dispersal. Ex-situ efforts to preserve carob genetic resources should prioritize accessions from both western and eastern populations, with emphasis on the most differentiated CEUs situated in South-Western Morocco, South Spain and Eastern Mediterranean. Our study underscores the relevance of natural and seminatural habitats of Mediterranean forests and their refugia in the conservation efforts of tree crops.

A Sicilian–Cretan biogeographical disjunction in the land snail genus Cornu (Gastropoda: Helicidae)

2020 ◽  
Author(s):  
Bernhard Hausdorf ◽  
Sonja Bamberger ◽  
Frank Walther
Keyword(s):  
Mediterranean Region ◽  
Eastern Mediterranean ◽  
Molecular Genetic ◽  
Divergence Time ◽  
Eastern Mediterranean Region ◽  
Land Snail ◽  
Western Mediterranean ◽  
Long Distance ◽  
Western Africa ◽  
The Mediterranean

Abstract We report an unusual biogeographical disjunction between the western and the eastern Mediterranean region. Cornu (Gastropoda: Helicidae) is a western Mediterranean land snail genus. It includes Cornu (Cornu) aspersum, which originated in north-western Africa and was distributed by humans for food or accidentally, first throughout the Mediterranean region and, subsequently, to all continents except Antarctica. It also includes three species belonging to the subgenus Erctella, which are all endemic to Sicily. We discovered a new species of Cornu on the Greek island of Crete. The morphological and molecular genetic analyses showed that the species from Crete is a disjunct representative of the subgenus Erctella. We hypothesize that the disjunction originated by a long-distance dispersal event of the ancestors of the Cretan species from Sicily by birds or by sea currents, perhaps facilitated by a tsunami or a similar event. The Cretan lineage separated from the Sicilian species in the Late Miocene or Early Pliocene. This divergence time is compatible with the hypothesis that the ancestor of Cornu cretense sp. nov. was washed from Sicily to Crete by the Zanclean flood that refilled the Mediterranean basin after it had dried up during the Messinian salinity crisis.

scholarly journals The antique genetic plight of the Mediterranean monk seal (Monachus monachus)

2021 ◽  
Author(s):  
Jordi Salmona ◽  
Julia Dayon ◽  
Emilie Lecompte ◽  
Alexandros A Karamanlidis ◽  
Alex Aguilar ◽  
...  
Keyword(s):  
Mediterranean Basin ◽  
Isolation By Distance ◽  
Late Quaternary ◽  
Eastern Mediterranean ◽  
Human Populations ◽  
Long Distance ◽  
Western Sahara ◽  
Quaternary Climate ◽  
The Mediterranean ◽  
The Impact

Disentangling the impact of Late Quaternary climate change from human activities can have crucial implications on the conservation of endangered species. We investigated the population genetics and demography of the Mediterranean monk seal (Monachus monachus), one of the world's most endangered marine mammals, through an unprecedented dataset encompassing historical (extinct) and extant populations from the eastern North Atlantic to the entire Mediterranean Basin. We show that Western-Sahara/Mauritania (Cabo Blanco), Madeira, Western Mediterranean (historical range) and Eastern Mediterranean regions segregate in four populations. This structure is likely the consequence of recent drift, combined with long-term isolation by distance (R2 = 0.7), resulting from prevailing short-distance (< 500 km) and infrequent long-distance dispersal (< 1,500 km). All populations (Madeira especially), show high levels of inbreeding and low levels of genetic diversity, seemingly declining since historical time, but surprisingly not being impacted by the 1997 massive die-off in Cabo Blanco. Approximate Bayesian Computation analyses support a scenario combining local extinctions and a major effective population size decline in all populations during Antiquity. Our results suggest that the early densification of human populations around the Mediterranean Basin coupled to the development of seafaring techniques were the main drivers of the decline of Mediterranean monk seals.

scholarly journals Mitogenomics of the endangered Mediterranean monk seal (Monachus monachus) reveals dramatic loss of diversity and supports historical gene-flow between Atlantic and eastern Mediterranean populations

2020 ◽  
Author(s):  
Alba Rey-Iglesia ◽  
Philippe Gaubert ◽  
Gonçalo Espregueira Themudo ◽  
Rosa Pires ◽  
Constanza De La Fuente ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
North Atlantic ◽  
Marine Mammals ◽  
Eastern Mediterranean ◽  
The Black Sea ◽  
Mediterranean Populations ◽  
Geographic Ranges ◽  
Western Sahara ◽  
The Mediterranean

Abstract The Mediterranean monk seal Monachus monachus is one of the most threatened marine mammals, with only 600–700 individuals restricted to three populations off the coast of Western Sahara and Madeira (North Atlantic) and between Greece and Turkey (eastern Mediterranean). Its original range was from the Black Sea (eastern Mediterranean) to Gambia (western African coast), but was drastically reduced by commercial hunting and human persecution since the early stages of marine exploitation. We here analyse 42 mitogenomes of Mediterranean monk seals, from across their present and historical geographic ranges to assess the species population dynamics over time. Our data show a decrease in genetic diversity in the last 200 years. Extant individuals presented an almost four-fold reduction in genetic diversity when compared to historical specimens. We also detect, for the first time, a clear segregation between the two North Atlantic populations, Madeira and Cabo Blanco, regardless of their geographical proximity. Moreover, we show the presence of historical gene-flow between the two water basins, the Atlantic Ocean and the Mediterranean Sea, and the presence of at least one extinct maternal lineage in the Mediterranean. Our work demonstrates the advantages of using full mitogenomes in phylogeographic and conservation genomic studies of threatened species.

scholarly journals Disentangling relationships among eastern Mediterranean Cymbalaria including description of a novel species from the southern Peloponnese (Greece)

2021 ◽  
Vol 307 (2) ◽  
Author(s):  
Pau Carnicero ◽  
Núria Garcia-Jacas ◽  
Llorenç Sáez ◽  
Theophanis Constantinidis ◽  
Mercè Galbany-Casals
Keyword(s):  
Eastern Mediterranean ◽  
Phylogenetic Analyses ◽  
Taxonomic Revision ◽  
Distribution Patterns ◽  
Morphological Characters ◽  
Molecular Data ◽  
Morphological Data ◽  
Long Distance ◽  
Aegean Islands ◽  
Molecular Phylogenetic

AbstractThe eastern Mediterranean basin hosts a remarkably high plant diversity. Historical connections between currently isolated areas across the Aegean region and long-distance dispersal events have been invoked to explain current distribution patterns of species. According to most recent treatments, at least two Cymbalaria species occur in this area, Cymbalaria microcalyx and C. longipes. The former comprises several intraspecific taxa, treated at different ranks by different authors based on morphological data, evidencing the need of a taxonomic revision. Additionally, some populations of C. microcalyx show exclusive morphological characters that do not match any described taxon. Here, we aim to shed light on the systematics of eastern Mediterranean Cymbalaria and to propose a classification informed by various sources of evidence. We performed molecular phylogenetic analyses using ITS, 3’ETS, ndhF and rpl32-trnL sequences and estimated the ploidy level of some taxa performing relative genome size measures. Molecular data combined with morphology support the division of traditionally delimited C. microcalyx into C. acutiloba, C. microcalyx and C. minor, corresponding to well-delimited nrDNA lineages. Furthermore, we propose to combine C. microcalyx subsp. paradoxa at the species level. A group of specimens previously thought to belong to Cymbalaria microcalyx constitute a well-defined phylogenetic and morphological entity and are described here as a new species, Cymbalaria spetae. Cymbalaria longipes is non-monophyletic, but characterized by being glabrous and diploid, unlike other eastern species. The nrDNA data suggest at least two dispersals from the mainland to the Aegean Islands, potentially facilitated by marine regressions.

scholarly journals Geomagnetic imprinting predicts spatio-temporal variation in homing migration of pink and sockeye salmon

2014 ◽  
Vol 11 (99) ◽  
pp. 20140542 ◽  
Author(s):  
Nathan F. Putman ◽  
Erica S. Jenkins ◽  
Catherine G. J. Michielsens ◽  
David L. G. Noakes
Keyword(s):  
Magnetic Field ◽  
Temporal Variation ◽  
Ocean Circulation ◽  
Sockeye Salmon ◽  
Movement Patterns ◽  
Oncorhynchus Gorbuscha ◽  
Migration Routes ◽  
Long Distance ◽  
Spatio Temporal ◽  
Olfactory Imprinting

Animals navigate using a variety of sensory cues, but how each is weighted during different phases of movement (e.g. dispersal, foraging, homing) is controversial. Here, we examine the geomagnetic and olfactory imprinting hypotheses of natal homing with datasets that recorded variation in the migratory routes of sockeye ( Oncorhynchus nerka ) and pink ( Oncorhynchus gorbuscha ) salmon returning from the Pacific Ocean to the Fraser River, British Columbia. Drift of the magnetic field (i.e. geomagnetic imprinting) uniquely accounted for 23.2% and 44.0% of the variation in migration routes for sockeye and pink salmon, respectively. Ocean circulation (i.e. olfactory imprinting) predicted 6.1% and 0.1% of the variation in sockeye and pink migration routes, respectively. Sea surface temperature (a variable influencing salmon distribution but not navigation, directly) accounted for 13.0% of the variation in sockeye migration but was unrelated to pink migration. These findings suggest that geomagnetic navigation plays an important role in long-distance homing in salmon and that consideration of navigation mechanisms can aid in the management of migratory fishes by better predicting movement patterns. Finally, given the diversity of animals that use the Earth's magnetic field for navigation, geomagnetic drift may provide a unifying explanation for spatio-temporal variation in the movement patterns of many species.

Effects of air quality on the health of Mediterranean forests

2021 ◽  
Author(s):  
Adrián García Bruzón ◽  
Patricia Arrogante Funes ◽  
Laura Muñoz Moral
Keyword(s):  
Climate Change ◽  
Machine Learning ◽  
Random Forest ◽  
Aridity Index ◽  
Plant Health ◽  
Mediterranean Forests ◽  
Random Forest Algorithm ◽  
The Mediterranean ◽  
Heterogeneous Variables ◽  
Peninsular Spain

&lt;p&gt;The climate change has turned out to be a determining factor in the development of forest in Spain. Production systems have emitted polluting gases and other particles into the atmosphere, for which some plants have not yet developed adaptation systems. Among the most harmful pollutants for the environment are gases such as nitrous oxides, ozone, particulate matter.&lt;/p&gt;&lt;p&gt;However, this condition is not the same in Peninsular Spain, and the Balearic Islands since the plant compositions differ in the territory and the bioclimatic, topographic, and anthropic characteristics. Monitoring the vegetation with sufficient spatial and temporal resolution, studying variables conditioning plant health is a challenge from the nature of the variables and the amount of data to be handled.&amp;#160;&lt;/p&gt;&lt;p&gt;The Mediterranean forest is one of the most ecosystem affected by climate change because of usually experimented long periods of drought that, in combination with increased temperatures, can drastically reduce the photosynthetic activity of trees and therefore the biomass of forests.&lt;/p&gt;&lt;p&gt;That is why the application of environmental technologies based on Remote Sensing (which provide plant health indices from passive sensors on satellite platforms and other variables of interest), Geographic Information Systems (to integrate, process, analyze spatial and temporal data) and machine learning models (which facilitate the extraction of relationships between variables, conditioning factors and predict patterns).&amp;#160;&lt;/p&gt;&lt;p&gt;In this regard, this work's objective is to evaluate the possible effect that different pollutants have on the health of the vegetation, measured from the annual values of the Normalized Difference Vegetation Index (NDVI), in the Mediterranean forests of Peninsular Spain. To achieve this, we are used machine learning techniques using the Random Forest algorithm. The study has also been done with various climatic, topographic, and anthropic variables that characterize the forest to carry it out.&amp;#160;&lt;/p&gt;&lt;p&gt;The results showed that certain variables such as the aridity index had generated the NDVI values and therefore plant development, while others are limiting factors such as the concentration of certain pollutants and the direct relationship between them particulates and NOx. This study can verify how the Random Forest algorithm offers reliable results, even when working with heterogeneous variables.&amp;#160;&lt;/p&gt;

The role of brush encroachment in Mediterranean ecosystems: a review

2021 ◽  
pp. 1-12
Author(s):  
Zalmen Henkin
Keyword(s):  
Eastern Mediterranean ◽  
Soil Nutrient ◽  
Fire Risk ◽  
Mediterranean Ecosystems ◽  
Climatic Conditions ◽  
Past Century ◽  
Great Success ◽  
Management Interventions ◽  
The Mediterranean ◽  
Efficient Option

Abstract Encroachment of woody plants into grasslands and subsequent brush management are among the most prominent changes occurring in arid and semiarid ecosystems over the past century. The reduced number of farms, the abandonment of marginal land and the decline of traditional farming practices have led to encroachment of the woody and shrubby components into grasslands. This phenomenon, specifically in the Mediterranean region, which is followed by a reduction in herbage production, biodiversity and increased fire risk, is generally considered an undesirable process. Sarcopoterium spinosum has had great success in the eastern Mediterranean as a colonizer and dominant bush species on a wide variety of sites and climatic conditions. In the Mediterranean dehesa, the high magnitude and intensity of shrub encroachment effects on pastures and on tree production were shown to be dependent on temporal variation. Accordingly, there are attempts to transform shrublands into grassland-woodland matrices by using different techniques. The main management interventions that are commonly used include grazing, woodcutting, shrub control with herbicides or by mechanical means, amelioration of plant mineral deficits in the soil, and fire. However, the effects of these various treatments on the shrubs under diverse environmental conditions were found to be largely context-specific. As such, the most efficient option for suppressing encroachment of shrubs is combining different interventions. Appropriate management of grazing, periodic control of the shrub component, and occasional soil nutrient amelioration can lead to the development of attractive open woodland with a productive herbaceous understory that provides a wider range of ecological services.

Age, growth and bathymetric distribution of red pandora (Pagellus erythrinus) on the Cretan shelf (eastern Mediterranean)

2002 ◽  
Vol 82 (1) ◽  
pp. 149-160 ◽  
Author(s):  
Stylianos Somarakis ◽  
Athanassios Machias
Keyword(s):  
Eastern Mediterranean ◽  
Negative Relationship ◽  
Biological Data ◽  
Growth Data ◽  
High Concentration ◽  
Bathymetric Distribution ◽  
Double Logarithmic Plot ◽  
Data Set ◽  
Pagellus Erythrinus ◽  
The Mediterranean

Data from bottom trawl surveys conducted each summer, winter and spring on the Cretan shelf from 1988 to 1991, were used to study the age, growth, maturity and bathymetric distribution of red pandora (Pagellus erythrinus). The good agreement of back-calculated and observed lengths-at-age with length frequencies and the marginal increment analysis, supported the annual nature of scale marks. A comparison of available growth data from the Mediterranean and the Atlantic revealed higher lengths-at-age for red pandora in the north-western Mediterranean and the Atlantic than in the central and eastern Mediterranean. The auximetric analysis, i.e. the double logarithmic plot of the parameter K of the von Bertalanffy growth function vs asymptotic length (L∞), showed a strong negative relationship for the central and eastern Mediterranean data set, implying a common ‘growth space’ for the populations in these areas. Lengths-at-maturity were lower on the Cretan shelf than in the Atlantic. These differences were attributed to the synergistic combination of trophic and thermal conditions.  Depth, temperature and salinity data were combined with biological data on abundance, fish size, age and maturity. In general, mean size increased with bottom depth because smaller individuals tended to be found in shallower and warmer waters. Individuals having reached first maturity were mainly distributed in the periphery of the algal/angiosperm meadows (60–80 m). All detailed studies of the bathymetric distribution and movements of shelf-dwelling demersal species (Mullus barbatus, Mullus surmuletus, Lepidotrigla cavillone and Pagellus erythrinus) in the Mediterranean show that these species are characterized by a spring–summer spawning season, a high concentration of spawning adults at mid-shelf depths, and nursery grounds located in the vegetated shallows. This multispecies pattern might have an adaptive function with both ecological and management implications.

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