This edition: Populations and Communities
Dr. Jack Burk and Dr. Gene Jones explain the importance of maintaining species, using as an example the Woolly Star, an endangered shrub in the alluvial fan of a river bed. Ultimately, every plant and animal in that community depends on the success of others for their survival. Keeping tabs on the population of the Woolly Star is the first step in protecting all of the organisms in the habitat.
In another relationship, an owl and a mouse illustrate predation in a grove of trees. Other examples of species interaction include commensalism and mutualism. The program explains the niches of the Great Horned Owl and the Common Barn Owl, which operate in an example of competitive exclusion. Finally, Dr. Lynn Carpenter explains, the way humans operate and adapt has made them, biologically speaking, one of the most successful species on Earth. Dr. John Weeks tells how population growth is affected by the relationship between birth rates and death rates.