STAT 2000 Lecture Notes - Lecture 10: Indicator Species, Epiphyte, Cestoda
Document Summary
** some basics of the biological component of the environment: 1. 75 million identified species on the earth. Environment: encompasses the sum total or aggregate of the conditions, surrounding things, or influences of a given organism(s). All the things, both biotic and abiotic, which interact with or influence that organism(s). Ecosystem: refers to a subset of the total earth environment and encompasses all the interactions within that subset. Ex: a desert ecosystem, or a tropical rainforest ecosystem, etc. Habitat usually refers to the subset of an ecosystem in which that organism/species lives. Ex: a fish lives within the lake habitat of a forest ecosystem. Many species will interact with numerous habitats and/or ecosystems. Evolution or biological evolution is the change in a population"s genetic makeup, or gene pool, through successive generations by the processes of mutation, natural selection, genetic drift, etc. * within the theory of evolution, all species descend from earlier, ancestral species by way of these changes.