Genomic signatures of isolation, hybridization, and selection during speciation of island finches

Sister species occurring sympatrically on islands are rare and offer unique opportunities to understand how speciation can proceed in the face of gene flow. The São Tomé grosbeak is a massive-billed, 'giant' finch endemic to the island of São Tomé in the Gulf of Guinea, where it has diverged from its co-occurring sister species the Príncipe seedeater, an average-sized finch that also inhabits two neighbouring islands. Here, we show that the grosbeak carries a large number of unique alleles different from all three Príncipe seedeater populations, but also shares many alleles with the sympatric São Tomé population of the seedeater, a genomic signature signifying divergence in isolation as well as subsequent introgressive hybridization. Furthermore, genomic segments that remain unique to the grosbeak are situated close to genes, including genes that determine bill morphology, suggesting the preservation of adaptive variation through natural selection during divergence with gene flow. This study reveals a complex speciation process whereby genetic drift, introgression, and selection during periods of isolation and secondary contact all have shaped the diverging genomes of these sympatric island endemic finches.

Potential Contribution of Climate Conditions on COVID-19 Pandemic Transmission over West and North African Countries

COVID-19, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is a very contagious disease that has killed many people worldwide. According to data from the World Health Organization (WHO), the spread of the disease appears to be slower in Africa. Although several studies have been published on the relationship between meteorological parameters and COVID-19 transmission, the effects of climate conditions on COVID-19 remain largely unexplored and without consensus. However, the transmission of COVID-19 and sensitivity to climate conditions are also not fully understood in Africa. Here, using available epidemiological data over 275 days (i.e., from 1 March to 30 November 2020) taken from the European Center for Disease Prevention and Control of the European Union database and daily data of surface air temperature specific humidity and water vapor from the National Center for Environmental Prediction (NCEP), this paper investigates the potential contribution of climate conditions on COVID-19 transmission over 16 selected countries throughout three climatic regions of Africa (i.e., Sahel, Maghreb, and Gulf of Guinea). The results highlight statistically significant inverse correlations between COVID-19 cases and temperature over the Maghreb and the Gulf of Guinea regions. In contrast, positive correlations are found over the Sahel area, especially in the central part, including Niger and Mali. Correlations with specific humidity and water vapor parameters display significant and positive values over the Sahelian and the Gulf of Guinea countries and negative values over the Maghreb countries. Then, the COVID-19 pandemic transmission is influenced differently across the three climatic regions: (i) cold and dry environmental conditions over the Maghreb; (ii) warm and humid conditions over the Sahel; and (iii) cold and humid conditions over the Gulf of Guinea. In addition, for all three climatic regions, even though the climate impact has been found to be significant, its effect appears to display a secondary role based on the explanatory power variance compared to non-climatic factors assumed to be dominated by socio-economic factors and early strong public health measures.

Maritime Security Governance: A New Strategy Management To Avoid Piracy In The Gog And Its Legal Guarantee

In the late 21st century, the growth of sea ships widened the horizons for trade on a global level. However, despite slow and cumulatively significant developments in transportation technology, during the era of sail, high sea maritime instability or the threats of piracy remained a significant obstacle to trade over long distances. In addition, with limited solidarity among all essential players in the region, several Gulf of Guinea (GoG) states can diversify their national attention to handle the pandemic instead of combating illegal activities at sea. Therefore, this article talks about the different factors of maritime piracy in the GoG, Comparing the trend across the region's different states (Togo, Benin, Nigeria, Ghana), the current maritime insecurity mitigation strategies proposed, and their gaps. Besides, a discussion around a knowledge gap in terms of accurate cooperation via the various policies implemented by those institutions brings us to propose coevolution governance in the shadow of the hierarchy and to create a maritime protect area (MPA) in the GoG country who do not have it yet, especially in Togo, Ghana, and Nigeria, and surround MPA with sustainably managed fishing areas where local small-scale fishers enjoy exclusive rights. The result shows that regionally it can help Centralize and diffuse the best practices, develop greater synergy among public policies and institutions, and nationally create greater sustainability of conservation with the integration of socio-economic concern and harmonization of strategic planning, practices, and policies.

Spatial Analysis of Maritime Piracy in the Gulf of Guinea

Humans rely on the sea for food and mineral resources; hence it is vital to their economic survival. Nations all throughout the world rely on the water for trade and commerce. This article looks at the present condition of marine security in the Gulf of Guinea. The Gulf of Guinea has a total shoreline of about 5,000 nautical miles and several natural harbours with dangerous weather. It has a significant crude oil reservoir, as well as fish and other natural resources. These traits provide huge prospects for marine trade and transportation, but the Gulf of Guinea is also riddled with maritime crimes of all types, including piracy and smuggling. Maritime piracy has presented a threat to coastal states’ stability and economic viability all across the world, not only in Africa. The study examines sea piracy in general, the Geographic Information System, and the impact of maritime piracy on the world socioeconomic development using secondary data. It then goes on to provide a number of recommendations aimed at addressing the problems caused by maritime piracy in the Gulf of Guinea in order to improve maritime security.