Evolutionary biology is an interdisciplinary field, concerned with the origin, change, multiplication, and diversification of self-replicating organisms over time. It integrates information from palaeontology and xenopalaeontology, planetology, studies of particular life forms from Terragen or non-Terragen biospheres, ecology, embryology, genetics, and many other fields. It has applications in studies of sophont psychology and culture, memetics, computing, and nanotechnology. The field had its origin in studies of biological organisms, but it has long since extended to the evolution of Turing-capable natural inorganic organisms such as the Rheolithoids or Hildemars Knots, to the evolution of artificial or modified biological forms that can reproduce after they have been created, and to the evolution of m-life, a-life, or other artificial organisms.
- Adaptation - Text by M. Alan Kazlev
Any alteration in the structure or function of an organism by natural selection, that helps it survive in its environment. In the most general sense, adaptation is a feedback process in which external changes in an environment are mirrored by compensatory internal changes in an adaptive system. The actions of the adaptive unit can affect the environment, which, in turn, feeds information back to the adaptive system. Examples include Darwinian biological and alife selection and genetic algorithms, social systems, organic and nanogenic immune systems, natural and artificial neural networks, AIs, neumanns, and more.
- Adaptive Radiation - Text by M. Alan Kazlev
The diversification of a morphotype or species as it adapts to different ecological niches. A single ancestral type in this way can evolve into a vast range of different descendants, each specialized for the new environment, and constituting a new phyle. May refer to both biological and alife replicators.
- Artificial Evolution - Text by M. Alan Kazlev
Directed evolution, evolution guided by artificial selection, controlled environments, gengineering, bionano, or other such means, as opposed to evolution left to natural selection.
- Attractor - Text by M. Alan Kazlev
An archetype or state that is characterization of the long-term behaviour of a dissipative dynamic system. Over long periods of time, the state space of some dynamical systems will contract toward this region. The Archailects are said to be dynamic systems that characterize particular attractors. Likewise, certain biological forms, certain memes, certain technological solutions, and so on, are known to have emerged independently on completely different planets or among different alien races.
- Autoevolution - Text by Anders Sandberg
Evolution directed by intelligent beings instead of natural selection.
Autoevolutionist: Someone who regards autoevolution as desirable; the opposite of a biological fundamentalist.
- Background Extinctions - Text by M. Alan Kazlev
Extinctions that occur continually throughout time. These extinctions are caused by small changes in climate or habitat, depleted resources, competition, and other changes that require adaptation and flexibility. Most extinctions (perhaps up to 95 per cent of all extinctions) occur as background extinctions.
- Cambrian Explosion - Text by M. Alan Kazlev
Period at the dawn of, or just preceding, the Cambrian period, when an unusual combination of environmental events (tectonic, atmospheric, ocean chemistry, climatic, ecological) triggered the sudden evolutionary radiation of terragen metazoa. These events are so unique and so distinctive that the term "Cambrian explosion" is used to refer to the sudden appearance of any higher ecologies and biota on a Gaian Type world previously only inhabited by microorganisms (or equivalent).
- Chromosome - Text by M. Alan Kazlev
In terragen biological life-forms, the individual self-replicating thread-like structures, containing the nucleotide sequence of DNA and along which the genes are located. In prokaryotes, chromosomal DNA is circular, and the entire genome is carried on one chromosome, which is distributed throughout the cell. In Eukaryotic cells the chromosomes are contained within the cellular nucleus, and the genome includes a number of chromosomes whose DNA is associated with different kinds of proteins.
- Clade (evolution) - Text by Stephen Inniss
A phylogenetic group of organisms (whether biological, neumann-capablem-life, or alife) that shares a particular common ancestor, and therefore are related and share similar features. In the case of naturally evolved organisms it can be difficult to determine whether they are actually a clade or whether there has been convergence towards a common morphotype. The original term from studies of evolution has been adapted to other uses. For this see clade (sophontology).
- Cladistics - Text by M. Alan Kazlev
The science of creating evolutionary trees of ancestry and descent; classifying organisms based on common ancestry and the branching of the evolutionary family tree. Organisms or entities that share common ancestors (and therefore have similar features) are grouped into taxonomic groups called clades. Cladistics can also be used to predict properties of yet-to-be discovered organisms. May refer to a biological phylogeny or a House or clan history.
- 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.
- Class (biology) - Text by M. Alan Kazlev
In the Linnean hierarchical classification, a group of related or similar organisms. A class contains one or more orders. A group of similar classes forms a phylum.
- 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.
- Competition - Text by M. Alan Kazlev
An interaction between or among two or more individuals, species, clades, corporations, nanecologies, polities, or empires, in which exploitation of resources by one affects any others negatively. A driving principle of evolution and of galactic society.
- 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.
- Darwin, Charles - Text by M. Alan Kazlev
Industrial age Old Earth scientist; founder and populariser of the theory of evolution by natural selection.
- Darwinian Evolution - Text by M. Alan Kazlev and Peter Kisner
Theory of biological evolution by natural selection based on the insights of Charles Darwin.
- Darwinism - Text by Stephen Inniss
Any of a range of biological or social ideas with an evolutionary basis, including but not limited to Darwin's theory of biological evolution by natural selection. Some of these have little or no connection with Darwin's original insight.
- Dysfunction - Text by Peter Kisner
In both organic, alife, and ai evolution there are many genetic variations that produce unsuccessful (non-viable) phenotypes. In some cases these genetic expressions would be successful in other environmental circumstances, but circumstances being what they are the mutation is lethal to it's recipient. Even with a wise parent computer designing it's offspring, it could still happen that the offspring does not work well in it's environment. Mentally these deficiencies could also be the case, although quite intelligent an AI could be unstable. Still, after many generations of AIs it might be expected that many harmful or self destructive tendencies would be selected out of the population.
- Endotherm - Text by M. Alan Kazlev
Organism that generates its own body temperature to maintain a relatively constant internal temperature, which is usually higher than (but may in some xenecologies be lower than) that of the surroundings. In terragen birds and mammals heat from the bloodstream circulates through the body in order to maintain the animal's temperature. Limners use a similar system but circulate paralymph rather than blood. To'u'ls use a cooling rather than a warming circulation, but again the principle is similar.
- Evolution (biology) - Text by M. Alan Kazlev
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.
- Evolutionarily Stable Strategy - Text by Anders Sandberg in his Transhumanist Terminology
Strategy which remains the most optimal even when there are a small number of individuals using other strategies in the population.
- 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 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).
- Extinction Event - Text by M. Alan Kazlev
Extinction of a lesser or greater number of biological or alife species, usually as a result of environmental trauma, deliberate extermination or assimilation (e.g. by a blight or swarm) or inability to compete with rival organisms.
- Family - Text by M. Alan Kazlev
In the Linnean system of classification, a monophyletic taxon of related and similar biological organisms. A family contains one or more genera. A group of similar families forms an order.
- Fitness - Text by M. Alan Kazlev
The measure of the ability of a biological organism, alife, or other replicator, to reproduce viable offspring.
- Fitness Landscape - Text by M. Alan Kazlev
An abstract or mathematical representation of how mutations can change the fitness of one or more organisms. Evolution will tend to make populations move in an uphill direction on the fitness landscape.
- Gamete - Text by M. Alan Kazlev
In Terragen life-forms that reproduce sexually, the mature male or female reproductive cell (sperm or ovum) with a haploid set of chromosomes (23 for baseline humans. A functionally similar configuration is found on a number of worlds with comparable xenobiota.
- Gene - Text by M. Alan Kazlev
Ordered sequence of nucleotides located in a particular locus on a particular chromosome that encodes a specific instructions for the cell, generally biochemical material, either RNA or protein. It includes regions involved in regulation of expression and regions that code for a specific functional product.
- Gene Expression - Text by M. Alan Kazlev
The process by which a gene's coded information is converted into the structures present and operating in the cell.
- Genetics - Text by M. Alan Kazlev
The study of heredity, genes, and the genome, both terragen and alien (this latter is sometimes called xenogenetics). Includes also the mapping of the genotype with the phenotype, simulation of past and future inheritance and evolutionary paths, and the basic theory behind gengineering.
- Genotype - Text by M. Alan Kazlev; additions by Stephen Inniss
Hereditary constitution of an individual; its genome (or equivalent, in artificial neumann-capable organisms or in xenobionts). Contrast with phenotype.
- Genus - Text by M. Alan Kazlev
In the Linnean system of classification, a monophyletic taxon of closely related and similar biological organisms. A genus contains one or more species. A group of similar genera forms a family. In the Linnean name of an organism, the first name is its genus, the second, the species.
- Insectomorph, Insectomorphic - Text by M. Alan Kazlev
Having insect-like form; distributed nervous system, exoskeleton, insectoidal or insectbot-like control systems, etc.
- Kingdom (biology) - Text by M. Alan Kazlev
In some forms of Linnean system of hierarchical classification, a kingdom is the highest grouping of similar organisms. Alternatively, the hierarchical grade between Phylum and Domain.
- Lamarckian Evolution - Text by Peter Kisner
Evolution through acquired characteristics. The concept was named after the early Industrial Age Old Earth scientist and evolutionist Jean Baptiste Lamarck, who explored the idea in detail, although the fundmental idea is not original to him. He thought to explain long term evolutionary change through this mechanism; a process where characteristics acquired by the parent are passed on to the child (i.e. giraffe ancestors stretched their necks more and more, passing on their long necks to their children). It was subsequently shown (Middle Industrial to Atomic Age Old Earth) shown that the mainspring of Terragen biotic evolution was actually the result of Darwinian selection and Mendelian inheritance; even though some traits are inherited in a Lamarckian fashion through epigenetic effects and have an effect from generation to generation they do not account for speciation.
Lamarckian Evolution in the case of AIs and even some highly reactive neogen biont clades is a valid description of their modes of longer term generational change.
- Macroevolution - Text by M. Alan Kazlev
In biological and slowly evolving alife, large-scale evolutionary trends above the species level.
- Mass Extinction - Text by M. Alan Kazlev
A process in which huge numbers of species on a garden world die out suddenly.
- 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.
- Monophyle - Text by M. Alan Kazlev
A phyle, clade, or any other group, the members of which share a common ancestry. Contrast with polyphyle.
- Mutation - Text by M. Alan Kazlev
Term coined by De Vries (old Earth early Atomic Age) for an abrupt inherited change of phenotype. Natural mutations are caused by a random change (usually damage) in the DNA sequence (Terragens) or in xenobiota or alife the analogue. Artificial mutations are an important element of gengineering and involve the deliberate alteration of the genetic material in order to achieve a desired phenotype. Types of biological mutations include point mutations, deletions, insertions, and changes in number and structure of chromosomes. In alifes mutations involve alteration in the code that determines the qualities that will be reproduced in new alife.
- Natural Selection - Text by M. Alan Kazlev
The process by which certain traits or qualities in an organism (whether biological or alife) are favoured (able to best survive), and hence randomly selected by local environmental pressures. This leads to changes in the genetic makeup of the species and, eventually, to a new species.
- Neospecies - Text by M. Alan Kazlev
 In Evolution theory - a newly (naturally) evolved species.
 A gengineered species.
- Order (biology) - Text by M. Alan Kazlev
In the Linnean system of nomenclature, the taxonomic rank between class and family. Refers to a group of basically similar of biological organisms, e.g. rodents, bats, elephants, primates, etc. The term is sometimes also applied to neogen and alife phyles, but with somewhat less success.
- Parasite - Text by M. Alan Kazlev
A biological organism or alife that lives off another organism (the host) without benefiting it. Hence Parasitism; relationship between two organisms in which one organism benefits at the other organism's expense.
- Phenotype - Text by M. Alan Kazlev
The appearance of an organism with respect to a particular group of physical, biochemical, and physiologic characteristics, as a result of the interaction of its genotype and its environment.
- 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 - e.g. biont, relativist, cycler, vec, bioborg, etc.
- Phylum - Text by M. Alan Kazlev
In the Linnean taxonomic classification, this is the second highest grading, and designates a phylum is a major group of organisms sharing a similar bodyplans. A phylum contains one or more classes. A group of similar phyla forms a Kingdom.
- Prebiotic - Text by M. Alan Kazlev
Conditions or environments conducive to the evolution of life, but in which life has not yet emerged or appeared.
- Predator-Prey System - Text by M. Alan Kazlev
A natural, artificial, or virtual ecosystem in which one portion of the population consumes another. With three or more species, simple predator-prey interactions can lead to chaos and biological or alife arms races.
- Quasispecies - Text by Manfred Eigen in Anders Sandberg's Transhuman Terminology
A fuzzy distributions of genotypes characterizing a population of quickly mutating organisms, alifes, or molecules.
- Radiation - Text by M. Alan Kazlev
 Any electromagnetic waves or atomic particles that transmit energy across space.
 One of three modes of heat (energy) transmission through stars or planets from warm regions to cool regions.
 Rapid evolution of a large number of morphotypes from a single ancestor.
- 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.
- Species - Text by M. Alan Kazlev
In the Linnean and neolinnean systems of biological classification, a taxonomic ranking between genus or subgenus and subspecies. It comprises related organisms or populations that are reproductively distinct and cannot produce fertile offspring by natural reproduction. The concept of a species is difficult to apply to prokaryotes (which reproduce asexually) and has also been rendered irrelevant by DIY germline engineering, tweaking and other forms of biotech. Nevertheless, the term is still popularity used as a convenient label for types of organic lifeforms.
- Subspecies - Text by M. Alan Kazlev
In the linnean and neolinnean systems of biological classification, the taxonomic ranking below species. The subspecies comprises related organisms or populations that are potentially capable of interbreeding and producing fertile offspring by natural reproduction. The concept of a subspecies has been rendered more or less irrelevant by DIY germline engineering, tweaking and other forms of biotech. Nevertheless, as with species, the term is still popularly used as a convenient label for types of organic lifeforms.
- Taxon - Text by M. Alan Kazlev
Formal supra-individual rank of biological or artificial organisms - e.g. species, phylum, etc. (pl. taxa).
- Terralife - Text by John B (credit to Jonathan Burns)
Any form of life which developed naturally on Terra (Old Earth). Specifically excludes any mods to the base lifeform.
- Variation - Text by M. Alan Kazlev
Genetic differences among individuals in a population, necessary for microevolution. In any population there are small differences between individuals of that population, clade or species. Some of these are beneficial to survival, others not. Both natural selection and artificial evolution involves selecting those variations that are beneficial to survival, or preferred by the designer. Alife that does contain any variations among a clade cannot evolve. For this reason, most alife is or was originally designed so as to vary like organic biota.