Biodiversity by John I. Spicer

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_____Cameron Kashani_____, a review of: Spicer, John I. 2009. Biodiversity. New York: Rosen Pub

Biodiversity and its decline is a subject often overlooked when talking about the dangers facing our planets ecosystem. A main reason for this seclusion is the vague nature of the word biodiversity. It is a term that has so many different meanings because of people’s different subjective interpretations. However at the Convention on Biological Diversity at Rio de Janeiro, Brazil in 1992, the term was defined as “the variability among living organisms from all sources including [among other things] terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are a part… [including] diversity within species, between species and of ecosystems.” The issue is in the method of quantifying such a description. The term Biodiversity is defined but is not measurable. This is the main issue for it being constantly overlooked. The book “Biodiversity” by John I. Spicer aims to bring light to the issue of its decline in our world’s ecosystems. Spicer begins by identifying what biodiversity is and to what extent it reaches. He continues then by describing the importance of biodiversity to the human race and the world. His goal is to communicate the relationship we have with biodiversity and how valuable it is to us. He then explains the harm being done to the ecosystems around the world, more specifically, how we as humans have been irresponsible in our relation to biodiversity and how our actions today are affecting the world tomorrow. Spicer is very adamant about his thoughts on this subject. His main objective in this book is to change the way people see biodiversity and make people feel the need to help keep it alive and fruitful. He concludes his book with his personal concerns and connections to the issue and implores us to become more responsible as a race and resident of this planet.

Spicer breaks the book up in to three major parts. The first of the three is his definition of what biodiversity encompasses. Initially he identifies the problem with quantification of biodiversity. He brings to light two very distinct findings that we must take into account before defining the term. First, as the sample area increases the number of species present is a result of “the balance between immigration and emigration, speciation and extinction.” Simply put, there is a balance that exists in each area based on the number of species leaving and entering the habitat and the number of new species growing and older species dying out. The second finding is more species present themselves in areas with “the greater number of different habitat types and environments in larger areas.” As environments get bigger they are able to house more habitats, increase species diversification. Spicer categorizes the more species rich areas as “biodiversity hotspots” and the lesser rich areas as “coldspots.” Using Norman Myers’ interpretations of the word “hotspot,” he used it to identify areas with large numbers of species that were found nowhere else, also using their threat level as a measure too. The definition of a hotspot is an area that contains “at least 1500 species of plant and must have lost at least 70% of its original habitat” (Spicer) Spicer is very convinced in his belief that to further recognize what biodiversity is we must categorize define the worlds evolution and how biodiversity is specific to particular regions in the world.

The book goes into William Sclater, author of The Geography of Mammals, scheme of dividing the earth’s surface into “Primary Regions” using the amount of similarity of animal life as the main guide. The surface is split into six parts, Spicer however discusses only the tropical ones- the Ethiopean region, Oriental region, Neotropical region. He notes that 70% of land organisms are home to these regions, with the Neotropical being the most biodiverse. He describes the types of animals and...
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