Adaptation (process)

The complementary match between organism and environment arises through interactions between natural selection and internally and externally expressed constructive development.

Constructive development

The developing organism shapes its own developmental trajectory by responding to environmental inputs and altering internal and external states.

Counteractive niche construction

Organisms either perturb their environments, or move in space, to wholly or partly reverse or neutralise some prior change in their environment.

Cryptic genetic variation

Genetic variation that normally has little or no effect on phenotypic variation but is expressed under atypical conditions.

Developmental bias

The nonrandom generation of phenotypes by developmental systems, with variants sometimes being channeled by the processes of development towards functional goals.

Ecological inheritance

The inheritance, via an external environment, of one or more natural selection pressures previously modified by niche-constructing organisms.

Ecosystem engineering

The modification by organisms of physical surroundings (e.g., light environment, physical habitat structure) so as to modulate the availability of resources or energy fluxes in an ecosystem


A transgenerational change in the distribution of heritable traits of a population.

Explanatory gap

The absence of a satisfactory causal chain linking causal inputs to outputs.

Extended evolutionary synthesis

A new evolutionary framework emphasizing that knowledge of how organisms develop, grow, and interact with environments helps to account for adaptation and the diversity of life.

Facilitated variation

Viable, adaptive or functional phenotypic variation, frequently generated through somatic selection processes in development (e.g. adaptive immunity).

Genetic accommodation

Gene frequency change due to selection on variation in the regulation, form, or side-effects of a novel trait.

Genetic assimilation

A form of ‘genetic accommodation’ that occurs when natural selection causes environmentally induced (i.e. plastic) phenotypes to lose their environmental sensitivity over evolutionary time.


All causal mechanisms by which offspring come to resemble their parents.

Inceptive niche construction

Organisms either perturb their environments, or move, to introduce a new change in one or more natural selection pressures.

Inclusive inheritance

Parental transference of developmental resources (mediated through genetic, epigenetic, physiological, behavioural and ecological inheritance mechanisms) that enable reconstruction of life cycles.


The sum of all the natural selection pressures to which the population is exposed.

Niche construction

The process whereby organisms, through their metabolism, their activities, and their choices, modify their own and/or each other’s niches.

Organismal agency

The capacity of living organisms to act on, and in, their world, and to modify their experience of it, including in ways that are neither predetermined, nor random. 


A class of individuals in a human population with a specified combination of a genotype and a variant of a cultural trait.

Phenotypic accommodation

The adaptive mutual adjustment during development of variable parts of an organism, without genetic change.

Phenotypic plasticity

Environmental induction leads to developmental reorganization and production of a novel phenotypic variant.

Plasticity-first evolution

A mechanism of adaptive evolution in which environmental induction leads to developmental reorganization and production of a novel developmental variant that is accommodated by individual phenotypes. If the environmental stimulus is recurrent, the phenotype will be refined and stabilized by genetic accommodation.

Positive niche construction

Niche-constructing acts that, on average, increase the fitness of the niche-constructing organisms. In the short run virtually all niche construction by individual organisms is expected to be positive.

Reciprocal causation

Process A is a cause of process B and, subsequently, process B is a cause of process A. Reciprocal causation captures the idea that developing organisms are not solely products, but are also causes, of evolution.

Relocational niche construction

Organisms actively move in space, as well as choose or bias the direction, the distance in space through which they travel, and the time when they travel, thereby modifying natural selection.

Semantic information

Adaptive, or possibly maladaptive “know how” carried by organisms typically, but not exclusively, in genomes.  In biology “know how” seldom carries cognitive connotations (Chaitin, 1987).