Persons who use tobacco or alcohol 40,41illegal drugs, including injection drugs and crack cocaine 42—47might also be at increased risk for infection and disease. However, because of multiple other potential risk factors that commonly occur among such persons, use of these substances has been difficult to identify as separate risk factors.
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".
The term's contracted form biodiversity may have been coined by W.
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 Appendix h hierarchy chart axis college it 210 given in a paper by Bruce A.
Wilcox's definition was "Biological diversity is the variety of life forms 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.
Hotspots[ edit ] A biodiversity hotspot is a region with a high level of endemic species that have experienced great habitat loss. Brazil 's Atlantic Forest is considered one such hotspot, containing roughly 20, plant species, 1, vertebrates and millions of insects, about half of which occur nowhere else.
Colombia is characterized by high biodiversity, with the highest rate of species by area unit worldwide and it has the largest number of endemics species that are not found naturally anywhere else of any country.
Selection bias amongst researchers may contribute to biased empirical research for modern estimates of biodiversity. Gilbert White succinctly observed of his Selborne, Hampshire "all nature is so full, that that district produces the most variety which is the most examined.
Evolution Apparent marine fossil diversity during the Phanerozoic  Biodiversity is the result of 3. The origin of life has not been definitely established by science, however some evidence suggests that life may already have been well-established only a few hundred million years after the formation of the Earth.
Until approximately million years ago, all life consisted of microorganisms — archaeabacteriaand single-celled protozoans and protists.
The history of biodiversity during the Phanerozoic the last million yearsstarts with rapid growth during the Cambrian explosion —a period during which nearly every phylum of multicellular organisms first appeared. Over the next million years or so, invertebrate diversity showed little overall trend and vertebrate diversity shows an overall exponential trend.
Vertebrates took 30 million years to recover from this event. Some scientists believe that corrected for sampling artifacts, modern biodiversity may not be much different from biodiversity million years ago. While records of life in the sea shows a logistic pattern of growth, life on land insects, plants and tetrapods shows an exponential rise in diversity.
As one author states, "Tetrapods have not yet invaded 64 per cent of potentially habitable modes and it could be that without human influence the ecological and taxonomic diversity of tetrapods would continue to increase in an exponential fashion until most or all of the available ecospace is filled.
Hyperbolic model implies a second-order positive feedback. The hyperbolic pattern of the world population growth arises from a second-order positive feedback between the population size and the rate of technological growth.Retail Catalog NoR SPRING err.^s^rr^_rr +^ea 0 q Helping you make things better This comput.
Event. Date. Global Population Statistics. The Spanish “Reconquest” of the Iberian peninsula ends in January with the conquest of Granada, the last city held by the Moors. Biodiversity is not evenly distributed, rather it varies greatly across the globe as well as within regions.
Among other factors, the diversity of all living things depends on temperature, precipitation, altitude, soils, geography and the presence of other leslutinsduphoenix.com study of the spatial distribution of organisms, species and ecosystems, is the science of biogeography.
The American Institute of Steel Construction (AISC), headquartered in Chicago, is a non-partisan, not-for-profit technical institute and trade association established in to serve the structural steel design community and construction industry in the United States.
🔥Citing and more! Add citations directly into your paper, Check for unintentional plagiarism and check for writing mistakes. IT/ Assignment: Currency Conversion Design · Complete the hierarchy chart in Appendix H and the flowcharts in Appendix I, based on the Currency Conversion requirements and Input-Process-Output table you generated in Week Two.
Key Link to Productivity (8th ed.) and the References within the References Page section of Ch. 2 .