Ecology

The universe can be organized along a spectrum of levels according to spatial scale. Ordered from the extremely small to the extremely large, these levels of integration are: subatomic particles, atoms, molecules, molecular mixtures, tissues, organs, individual organisms, populations of individuals, communities of populations, ecological landscapes, the biosphere, the solar system, the galaxy, and the universe. Within this larger scheme, the usual realm of ecology involves the levels ranging from (and including) individual organisms through to the biosphere. These elements of the ecological hierarchy are described below in more detail.