Defining and Understanding Biodiversity
Understanding Biodiversity
- Biodiversity refers to the variety of life at different levels of biological organization. This encapsulates genetic diversity, species diversity, and ecosystem diversity.
Genetic Diversity
- Genetic diversity is the variety of genes possessed by the individuals making up a population, species, or community.
- More genetic diversity ensures long-term viability of a species because it provides more opportunities for adaptation to changing environments.
- Inbreeding reduces genetic diversity; conversely, a wide gene pool promotes it.
Species Diversity
- Species diversity includes two components: species richness (the number of different species in an area) and species evenness (does one species dominate the area or are species numbers fairly equal).
- A higher degree of species diversity generally contributes to the stability of an ecosystem, as a variety of species can compensate for changes in the environment.
Ecosystem Diversity
- Ecosystem diversity refers to the variety of different ecosystems on the Earth.
- Each ecosystem contains unique combinations of species, interactions between these species, and physical conditions under which these species live.
Defining and Identifying Species
- The biological species concept binds species as groups of organisms that can breed together to produce fertile offspring.
- This definition has limitations, particularly for organisms that reproduce asexually, don’t currently have the opportunity to interbreed, or for extinct groups of organisms.
- The phylogenetic species concept identifies species based on the evolutionary history of the population.
- The morphological species concept categorizes species based on observable physical features.
The Importance of Biodiversity
- Biodiversity contributes to everything from ecosystem services such as decomposition, water purification, and pollination, to cultural, spiritual, recreational, and aesthetic values.
- Biodiversity is important to human survival as it provides food, fibres, and medicinal resources; it also ensures the availability of a healthy gene pool for future use.
Threats to Biodiversity
- Threats to biodiversity include habitat loss, overexploitation, invasive species, pollution, and climate change.
- Conserving biodiversity requires understanding threats and their impacts as well as taking action to mitigate or limit those threats.
- Conservation strategies may include establishing protected areas, restoring degraded habitats, reintroducing species, and implementing laws and regulations.