Chapter 57 – Conservation Biology
What is Conservation Biology?
- Conservation Biology: An applied scientific discipline devoted to preserving the diversity of life on
- Difference in conservation biology now: (i) multidisciplinary, (ii) doesn’t only concentrate on species that
- Conservation biology is a normative scientific discipline. Normative = the embracing of certain values
and the application of the scientific method in order to achieve these values. Conservation biology is a
normative scientific discipline; not neutral.
- Conservation biology is guided by 3 principles:
1. Evolution is the process that unites all of biology (you must know how evolutionary processes
generate and maintain biodiversity to be able to preserve it)
2. The ecological world is dynamic therefore they is no static “balance of nature” that serves as a
goal of conservation activities.
3. Humans are a part of ecosystems; human activities need to be incorporated into conservation
goals and practices
- The process of species extinction is a natural one, which has been done for millions of years – even if
humans were not on this Earth, extinction would occur, but our presence is causing it to become a
-The value of biodiversity to humans:
- Humans depends on other species for food, fibre and medicine
- Humans derive aesthetic pleasure from interacting with other organisms
- Causing the extinction of other species raises serious ethical issues
- Extinctions make the study of ecological relationships and species interactions difficult
•More species lost/extinct, the harder it is to understand the structure and the
functioning of ecological communities and ecosystems
57.2 How Do Biologists Predict Changes in Biodiversity?
- Species-area relationship = a well-established mathematical relationship between the size of an area
and the number of species that area contains.
- Rare species are not a concern because they probably depend on highly specialized habitats and have
always been rare, but newly rare species are.
- Conservation biologists use a statistical model that incorporates information about population size,
genetic variation, morphology, physiology, and behaviour of its members.
- Ex: The golden toad of Costa Rica disappeared because clouds moved higher up the mountains due to
climate change, and the forest became too dry for the toad.
57.3 What Factors Threaten Species Survival?
- Habitat loss is the primary cause of species endangerment in the U.S., especially those that live in
- Habitat Fragmentation: The isolation and reduction in size of habitats due to the destruction of other
- Invasive plants have high rates of growth and reproduction, in part because they invest less energy in
producing defensive compounds. The invaders thus tend to take advantage of soil nutrients in ways that
the native plants cannot.
r- Ex: Birds below 1500 meters elevation in Hawaiian islands eliminated by avian malaria.