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I am a senior biology major at Bryn Mawr College. My main area of interest is ecology.

Biodiversity is the variation in forms of life at a given spatial and temporal scale. The biodiversity could be measured at the level of species, communities, and ecosystems, up to a global scale and over many time periods. It is used to evaluate the health of they system. It is important to create an experiment with the appropriate spatial and temporal scales for the hypothesis being tested. Biodiversity also has several components. Species diversity for example, is calculated using measurements of both species richness (number of species) and species evenness (how many of each species).

Globally biodiversity is decreasing. This could be a reflection of decreasing health in the global environment. Life forms have existed on earth for several million years. During this time the global biodiversity has certainly fluctuated. We must use the data on extinction rates and other measures of biodiversity to decide for ourselves if this decline is part of that background fluctuation or truly an anomaly.

If the interpretation of the data suggests an anomalous decrease in biodiversity, why should we care? We care because we too are a species on this earth that is subject to extinction. In a less extreme case humans are connected to other life forms, whether it is through ecosystem services or a love of nature. Humans have the power to alter the environment both locally and globally. This manipulation often has a goal in mind, whether it is through development, flood prevention, habitat protection. We can better predict the outcomes of these manipulations if given information about the health and makeup of ecosystems.