Explain the concept of biodiversity and how it is measured.
Biodiversity exists at three scales: ecosystem diversity, species diversity, and genetic diversity. Environmental scientists measure species diversity both by the number of species in a particular location (species richness) and by how evenly individuals are distributed among those species (species evenness). The greater the number of species, and the more even the distribution, the higher the diversity.
The H1N1 swine flu virus has become a pandemic. James Williams takes a look at where the swine flu originated and what happens to the virus once it gets inside our bodies.
Our planet’s diverse, thriving ecosystems may seem like permanent fixtures, but they’re actually vulnerable to collapse. Jungles can become deserts, and reefs can become lifeless rocks. What makes one ecosystem strong and another weak in the face of change? Kim Preshoff details why the answer, to a large extent, is biodiversity.
Chapter 21: Phylogeny and the Classification of Organisms