BIOL 107 Lecture Notes - Overexploitation, Habitat Destruction, Biogeography
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Chapter 57: Conservation Biology
57.1 What is Conservation Biology?
•Devoted to preserving the diversity of life on Earth
•Draws heavily on concepts and knowledge from population genetics,
evolution, ecology, biogeography, wildlife management, economics and
Conservation biology is a normative scientific discipline
•Conservation biology is a normative discipline embraces certain values
and applies scientific methods to the goal of achieving these values;
motivated by the belief that preservation of biodiversity is good and that loss
•Is guided by three principles:
oEvolution is a process that unites all of biology.
oThe ecological world is dynamic.
oHumans are a part of ecosystems.
Conservation biology aims to prevent species extinctions
•Organisms have always altered Earth’s ecosystems.
•Very first organisms probably reduced the supply of energetically and
structurally useful compounds (replacing them with waste products).
•Early photosynthetic prokaryotes and eukaryotes generated oxygen
(unsuitable for anaerobic organisms).
•Plants colonized the land, accelerating the weathering of rocks thus, gaining
access to rock-bound nutrients.
•Weathering of phosphorus increased global productivity = rise of oxygen
•Rise of vascular plants increased oxygen concentration; lower carbon dioxide
•Human beings cause extinctions of other species
oWhen first arrived in N. America (20 000 years ago), encountered a
rich fauna of large mammals.
oMost species were exterminated (overhunting) within a few thousand
•The productivity and richness of Earth’s biota has increased during the long
course of life’s evolution, but current situation is unique: all environmental
changes are being caused by a single species.
•That’s why now more and more people value biodiversity for many reasons:
oHumans depend on other species for food, fiber, and medicine
oSpecies are necessary for the functioning of ecosystems and its many
benefits and services.
oHumans derive enormous aesthetic pleasure from interacting with
oExtinctions deprive us of opportunities to study and understand
ecological relationships among organisms.
oLiving in ways that cause the extinction of other species raises serious
57.2 How Do Biologists Predict Changes in Biodiversity?