The classification system in use by the biological sciences today to classify all living things. It was invented by and subsequently named after an 18th century Swedish botanist. With this system, organisms are classified according to the greater or lesser extent of their similarities to other organisms. | Linnaean classification system |
The process of naming, describing, and classifying organisms into different categories on the basis of evolutionary relationships. The biological sciences primarily use the Linnaean classification system for this purpose. | taxonomy |
The term for the two Latin name categories (genus and species) used in the Linnaean classification system to designate each type of organism. The term you are looking for literally means "two names" in Latin. | binomen or binomial nomenclature |
The largest natural population of organisms that can potentially interbreed to produce fertile offspring. | species |
A group of closely related species. In the Linnaean classification system, this is the category immediately above species. | genus (plural genera) |
The genus and species of all living humans. | Homo sapiens |
The biological order that includes all species of monkeys, apes, and humans. The word was derived from a Latin word meaning “first.” | Primates |
The expansion and diversification of an evolving group of organisms as they adapt to new ecological niches. This is the process by which one species evolves into two or more species. It occurs as a result of different populations becoming reproductively isolated from each other, usually by adapting to different environments. | adaptive radiation |
An evolutionary mechanism that occurs when some individuals of a population are better able to adapt to their environment and, subsequently, produce more offspring. Nature, in effect, selects which members of a population are fit to survive long enough to reproduce. Differential productive success between individuals is the key. Those who produce more offspring have a greater influence on the gene frequencies of the next generation. | natural selection |
Similar anatomical structures in different species that were not present in their common ancestor. | homoplasies or homoplastic structures |
Anatomical structures in different species that are similar due to descent from a common ancestor that had them. An example would be the same functional types of bones in the front leg of a bear and your arm as well as in the front leg of our common reptilian ancestor. | homologies or homologous structures |
A similar evolutionary development in different species lines after divergence from a common ancestor that had the initial anatomical feature that led to it. This is thought to be due primarily to the independent species lines experiencing the same kinds of natural selection pressures. This results in homoplasies. An example would be the independent evolution of large body size among some species of New and Old World monkeys. | parallelism or parallel evolution |
The development of a similar anatomical feature in distinct species lines after divergence from a common ancestor that did not have the initial trait that led to it. The common ancestor is usually more distant in time than is the case with parallelism. This phenomenon is thought to be due primarily to the independent species lines experiencing the same kinds of natural selection pressures. This results in homoplasies. An example would be the similar appearance and predatory behavior of North American wolves and Tasmanian wolves. | convergence or convergent evolution |
Anatomical features that have the same form or function in different species that have no known common ancestor. An example would be the wings of a bird and a butterfly. | analogies or analogous structures |