Four additional slave-holding states — VirginiaArkansasTennesseeand North Carolina — declared their secession and joined the Confederacy following a call by U. President Abraham Lincoln for troops from each state to recapture Sumter and other seized federal properties in the South. The antebellum state governments in both maintained their representation in the Union. Efforts by certain factions in Maryland to secede were halted by federal imposition of martial law ; Delawarethough of divided loyalty, did not attempt it.
Etymology[ edit ] The term biological diversity was used first by wildlife scientist and conservationist Raymond F.
Dasmann in the year lay book A Different Kind of Country  advocating conservation. The term was widely adopted only after more than a decade, when in the s it came into common usage in science and environmental policy.
Thomas Lovejoyin the foreword to the book Conservation Biology,  introduced the term to the scientific community. Jenkins,  Lovejoy and other leading conservation scientists at the time in America advocated the use of the term "biological diversity".
It first appeared in a publication in when sociobiologist E.
Wilson used it as the title of the proceedings  of that forum. A similar term in the United States is "natural heritage. Broader than biodiversity, it includes geology and landforms.
Biologists most often define biodiversity as the "totality of genes, species and ecosystems of a region". An explicit definition consistent with this interpretation was first given in a paper by Bruce A. They study processes such as mutation and gene transfer that drive evolution.
However, tetrapod terrestrial vertebrates taxonomic and ecological diversity shows a very close correlation. Among other factors, the diversity of all living things biota depends on temperature, precipitation, altitude, soilsgeography and the presence of other species.
The study of the spatial distribution of organismsspecies and ecosystemsis the science of biogeography.
Diversity consistently measures higher in the tropics and in other localized regions such as the Cape Floristic Region and lower in polar regions generally. Latitudinal gradients in species diversity Generally, there is an increase in biodiversity from the poles to the tropics.
Thus localities at lower latitudes have more species than localities at higher latitudes. This is often referred to as the latitudinal gradient in species diversity. Several ecological mechanisms may contribute to the gradient, but the ultimate factor behind many of them is the greater mean temperature at the equator compared to that of the poles.
This hypothesis considers temperaturemoistureand net primary production NPP as the main variables of an ecosystem niche and as the axis of the ecological hypervolume.
In this way, it is possible to build fractal hypervolumes, whose fractal dimension rises up to three moving towards the equator.The Confederate States of America (CSA or C.S.), commonly referred to as the Confederacy and the South, was an unrecognized country in North America that existed from to The Confederacy was originally formed by seven secessionist slave-holding states—South Carolina, Mississippi, Florida, Alabama, Georgia, Louisiana, and Texas—in the Lower South region of the United States, whose.
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Explore and learn more about . Vitamin D is a fat-soluble essential vitamin that our skin synthesizes when exposed to the sun. It benefits us in many ways, from bone health to mood.
Our evidence-based analysis features unique references to scientific papers. A social class is a set of subjectively defined concepts in the social sciences and political theory centered on models of social stratification in which people are grouped into a set of hierarchical social categories, the most common being the upper, middle and lower classes.
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