Describes six levels of organization in the biological world - individual species, population, community, ecosystem, biome, and biosphere.

Abiotic factors vary in the environment and determining the types and numbers of organisms that exist in that environment. Factors which determine the types and numbers of organisms of a species in an ecosystem are called limiting...

A collection of video lectures introducing beginning biology students to the principles of evolution, ecology, and behavior. The course was taught three times a week for a semester at Yale University. The course discusses concepts of...