An interactor is a person who interacts with the members of the audience.
or
An interactor is an entity that natural selection acts upon.
Definition
Interactor is a concept commonly used in the field of
evolutionary biology
Evolutionary biology is the subfield of biology that studies the evolutionary processes ( natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life ...
. A widely accepted
theory of evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variatio ...
is the theory from
Charles Darwin
Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended ...
. He states, in short, that in a
population
Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using a ...
there is often variation in heritable traits among individuals, in which a form of the trait might be more beneficial than the other form(s). Due to this difference the change of getting more adjusted offspring to the environment is higher.
[ On the Origin of Species#Content] The process describing the selection of the environment on the traits of organisms is called natural selection. Based on this idea natural selection seems to act on traits of individuals, which evolutionary biologist like to call the interactor. So stated in a different way; an interactor is defined as a part of an
organism
In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and ...
that
natural selection
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Cha ...
acts upon.
Replicators and vehicles
Replicators
Other terms that are often mentioned in the same context as interactors, are replicators and vehicles. When
replicators are mentioned, they mean things that pass on their entire structure through successive replications, like genes. This is not the same as an interactor, as interactors are things that interact with their environment and natural selection can act upon. Due to this interaction with the environment, interactors cause differential replication. However, some things (for example genes) can be both replicators and interactors.
Vehicles
Vehicles are often used as a synonym of interactors, only in a way that vehicles can "drive" natural selection, as if they have the behaviour to steer natural selection in a specific way. The term "vehicle" makes it look that way and therefore some people (like
Hull) prefer the word "interactor" to "vehicle" for the same concept. An example of an interactor is the shell colour of snails (see below).
Research on common garden snails as illustration for natural selection and interactors
A study on common garden snails was performed and showed how natural selection on an interactor works. This
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
is highly suitable for evolutionary research due to their easily to score
phenotype
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological pr ...
and their very straightforward genotype causing the
phenotypic variation
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological prop ...
. Phenotypic variation among common garden snails can be found in their shell colour and banding and both colouring and banding is regulated by one single
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
. The snail shells have variations in colours namely brown, pink and yellow; with brown being more
dominant than pink and yellow. Furthermore, banding variation can be described as unbanded and banded, with banded individuals differing from another by the number of bands. One of the conclusions that could be drawn out of this research is that in grasslands, yellow individuals had a higher survival rate and were more abundant in these grasslands. This means that natural selection acted on the shell colour, which means that shell colour is the interactor in this example. Furthermore, they found that the brown individuals were more abundant and had a higher survival rate in woodlands than the yellow individuals. Moreover, a specific form of natural selection called thermal selection showed that shell colour worked in the interaction with the environment by yellow shells being more abundant, so more adjusted to reflect heat, in warmer places.
References
''Science and Selection'', David Hull, 2001 (http://assets.cambridge.org/97805216/43399/sample/9780521643399ws.pdf)
''Replication and Reproduction'', David Hull, 2001 (https://plato.stanford.edu/entries/replication/
)
Color polymorphism in a land snail Cepaea nemoralis (Pulmonata: Helicidae) as viewed by potential avian predators, Adrian Surmacki & Agata Ożarowska-Nowicka & Zuzanna M. Rosin, 2013 (https://link.springer.com/content/pdf/10.1007/s00114-013-1049-y.pdf)
''
On the Origin of Species
''On the Origin of Species'' (or, more completely, ''On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life''),The book's full original title was ''On the Origin of Species by Me ...
,'' Charles Darwin, 1859
External links
{{Wiktionary
The Role of Behavior in EvolutionInteractors is also an IT Company
Evolutionary biology