Evolution (biology)
In biology and systems theory, descent with modification. The process by which the gene pool of a population gradually changes in response to environmental pressures, natural selection, and genetic mutations.

Evolution operates on populations that involve variation among individuals, traits being inheritable, and a level of fitness for individuals that is a function of the possessed traits. Evolution produces permanent change in the morphology and function of adult living organisms, so that ancestor taxa are modified into descendant taxa. Over relatively long periods of time, the distribution of inheritable traits will tend to reflect the fitness that the traits convey to the individual; thus, evolution acts as a filter that selects fitness-yielding traits over other traits. These changes take place over chronologically successive generations between chronologically successive populations within clades or species (microevolution), or involve the emergence of new clades, species and higher taxa (macroevolution). The theory of evolution through natural selection was first proposed by Old Earth hu Charles Darwin. See also artificial evolution.
Related Articles
  • Artificial Evolution, Autoevolution - Text by M. Alan Kazlev
    Directed evolution, evolution guided by intelligent beings using artificial selection, controlled environments, gengineering, bionano, or other such means. Contrast with evolution left to natural selection. Sometimes called autoevolution when intelligent beings apply it to themselves.
  • Clade (evolution)
  • Cladogram (evolution) - Text by M. Alan Kazlev
    Branching diagram that depicts divergence of the analysed taxa from their common ancestors. It shows the distribution and origins of unique shared characteristics (synapomorphies and autapomorphies), as well as their monophyly. A testable hypotheses of phylogenetic relationships.
  • Coevolution - Text by M. Alan Kazlev
    Two or more organisms experiencing evolution in response to one another. This may result in a biological arms race, or it could produce a symbiotic relationship.
  • Convergent Evolution - Text by M. Alan Kazlev
    When a trait develops independently in two or more evolutionary sequences or groups of organisms; e.g. the development of skin-flap wings in pterodactyls and bats. Mathematically, this refers to dynamic systems settling into an attractor.
  • Darwinian Evolution
  • Evolution (esoterics)
  • Evolution (philosophy)
  • Evolution (sophontology)
  • Evolutionary Algorithm - Text by M. Alan Kazlev
    A computer program that simulates the processes biological evolution; a problem-solving system that use computational models of evolution as key elements of design. All alife, evolutionary ai and aioids, and self-evolving virchworlds are determined by evolutionary algorithms.
  • Evolutionary Track - Text by M. Alan Kazlev
    The change in location of a star on the Hertzsprung - Russell (H-R) Diagram. As a star ages and evolves, you can trace out its history on the H-R diagram.
  • Evolutionary Tree - Text by M. Alan Kazlev
    Phylogenetic or cladistic diagram tracing ancestry-descent, branching, cross-links of genetic/informational and morphotypic exchange, and other factors in order to provide a complete and usually multi-parameter diagram of the evolutionary history of any taxon. A beautiful collection of evolutionary trees can be seen in the great Phylogeny Orbitals of Darwinia (NuiHibbert Sector, Zoeific Biopolity).
  • Lamarckian Evolution
  • Macroevolution
  • Megaevolution - Text by M. Alan Kazlev
    Dramatic evolutionary change, for example the appearance of new phyla or even kingdoms of organisms. An example is the Cambrian explosion on old Earth. Natural megaevolution only occurs infrequently (often no more than once or several times on a Garden World), but gengineers and biosculptors frequently create radical new organisms by biotech and bionano means.
  • Microevolution - Text by M. Alan Kazlev
    Morphologic change through natural selection within a species, leading eventually to the evolution of a new species. Most common through genetic drift of small populations on individual habitats. Wild bionano can also encourage microevolution, even among large population pools. Microevolution eventually results in macroevolution.
  • Phyle - Text by M. Alan Kazlev
    A major category of sentient beings, as defined by one or a few basic but distinctive qualities, not necessarily connected by ancestry — a biont, relativist, cycler, vec, bioborg, or some similarly large group of varying descent.
  • Phylogeny - Text by M. Alan Kazlev
    The science and art of tracing family trees of ancestry and descent, whether regarding the evolution of species over millions of years, or of terragen clades or genetic houses over thousands of years.
  • Software Based Evolution - Text by M. Alan Kazlev
    Software simulation of the evolutionary process; the fundamental principle of alife. Beginning in the early information period, software-based evolution enabled "creatures" which are software simulations of biological organisms, in which each cell has its own DNA-like genetic code. Digital organisms and subsophont alifes compete with one another for the limited simulated space and energy resources of their simulated environment. Although many other variations have since been used, darwinian selection remains a potent factor in the evolution and cladization of alife.
  • To'ul'h Prime Phylogenetic Tree
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Development Notes
Text by M. Alan Kazlev
Initially published on 24 October 2001.