Co-evolution - AbsoluteAstronomy.com

In biology, coevolution is "the change of a biological object triggered by the change of a related object." Coevolution can occur at many biological levels: it can be as microscopic as correlated mutations between amino acids in a protein, or as macroscopic as covarying traits between different species in an environment. Each party in a coevolutionary relationship exerts selective pressures

Selection

In the context of evolution, certain traits or alleles of genes segregating within a population may be subject to selection. Under selection, individuals with advantageous or "adaptive" traits tend to be more successful than their peers reproductively—meaning they contribute more offspring to the...

on the other, thereby affecting each other's evolution. Coevolution of different species includes the evolution of a host species and its parasites (host–parasite coevolution), and examples of mutualism evolving through time. Evolution in response to abiotic factors, such as climate change

Climate change

Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...

, is not coevolution (since climate is not alive and does not undergo biological evolution). Coevolution between pairs of entities exists, such as that between predator and prey

Predation

In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...

, host and symbiont or host and parasite, but many cases are less clearcut: a species may evolve in response to a number of other species, each of which is also evolving in response to a set of species. This situation has been referred to as "diffuse coevolution."

There is little evidence of coevolution driving large-scale changes in Earth's history, since abiotic factors such as mass extinction and expansion into ecospace seem to guide the shifts in the abundance of major groups. However, there is evidence for coevolution at the level of populations and species. For example, the concept of coevolution was briefly described by Charles Darwin

Charles Darwin

Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...

in On the Origin of Species, and developed in detail in Fertilisation of Orchids
Fertilisation of Orchids
Fertilisation of Orchids is a book by Charles Darwin published on 15 May 1862 under the full explanatory title On the various contrivances by which British and foreign orchids are fertilised by insects, and on the good effects of intercrossing...

. It is likely that virus

Virus

A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

es and their hosts may have coevolved in various scenarios.

Coevolution is primarily a biological concept, but has been applied by analogy to fields such as computer science

Computer science

Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...

and astronomy

Astronomy

Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

Models

One model of coevolution was Leigh Van Valen

Leigh Van Valen

Leigh Maiorana Van Valen was an American evolutionary biologist. He was professor emeritus in the Department of Ecology and Evolution at the University of Chicago....

's Red Queen's Hypothesis

Red Queen's Hypothesis

The Red Queen's Hypothesis, also referred to as Red Queen, Red Queen's race or Red Queen Effect, is an evolutionary hypothesis. The term is taken from the Red Queen's race in Lewis Carroll's Through the Looking-Glass...

, which states that "for an evolutionary system, continuing development is needed just in order to maintain its fitness relative to the systems it is co-evolving with".

Emphasizing the importance of sexual conflict

Sexual conflict

Sexual conflict occurs when the two sexes have conflicting optimal fitness strategies concerning reproduction, particularly the mode and frequency of mating, leading to an evolutionary arms race between males and females. The conflict encompasses the actions and behaviors of both sexes to influence...

, Thierry Lodé

Thierry Lodé

Thierry Lodé is a French biologist and professor who teaches evolutionary ecology in the CNRS Units ETHOS...

described the role of antagonist interactions in evolution, giving rise to a concept of antagonist coevolution.

Coevolution branching strategies for asexual population dynamics in limited resource environments have been modeled using the generalized Lotka–Volterra equations.

Hummingbirds and ornithophilous flowers

Hummingbird

Hummingbirds are birds that comprise the family Trochilidae. They are among the smallest of birds, most species measuring in the 7.5–13 cm range. Indeed, the smallest extant bird species is a hummingbird, the 5-cm Bee Hummingbird. They can hover in mid-air by rapidly flapping their wings...

s and ornithophilous (bird-pollinated) flowers have evolved a mutualistic relationship. The flowers have nectar suited to the birds' diet, their color suits the birds' vision and their shape fits that of the birds' bills. The blooming times of the flowers have also been found to coincide with hummingbirds' breeding seasons.

Flowers have converged to take advantage of similar birds. Flowers compete for pollinators, and adaptations reduce unfavourable effects of this competition. Bird-pollinated flowers usually have higher volumes of nectar and higher sugar production than those pollinated by insects. This meets the birds' high energy requirements, which are the most important determinants of their flower choice. Following their respective breeding seasons, several species of hummingbirds occur at the same locations in North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, and several hummingbird flowers bloom simultaneously in these habitats. These flowers seem to have converged to a common morphology

Morphology (biology)

In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....

and color. Different lengths and curvatures of the corolla tubes can affect the efficiency of extraction in hummingbird species in relation to differences in bill morphology. Tubular flowers force a bird to orient its bill in a particular way when probing the flower, especially when the bill and corolla are both curved; this also allows the plant to place pollen

Pollen

Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...

on a certain part of the bird's body. This opens the door for a variety of morphological co-adaptations.

An important requirement for attraction is conspicuousness to birds, which reflects the properties of avian vision and habitat features. Birds have their greatest spectral sensitivity and finest hue discrimination at the red end of the visual spectrum, so red is particularly conspicuous to them. Hummingbirds may also be able to see ultraviolet "colors". The prevalence of ultraviolet patterns and nectar guides in nectar-poor entomophilous (insect-pollinated) flowers warns the bird to avoid these flowers.

Hummingbirds form the family Trochilidae, whose two subfamilies are the Phaethornithinae (hermits) and the Trochilinae

Trochilinae

Trochilinae is a subfamily of the hummingbird family . Members of the subfamily Trochilinae are sometimes called typical hummingbirds. They typically display iridescent plumage in metallic reds, oranges, greens and/or blues...

. Each subfamily has evolved in conjunction with a particular set of flowers. Most Phaethornithinae species are associated with large monocotyledon

Monocotyledon

Monocotyledons, also known as monocots, are one of two major groups of flowering plants that are traditionally recognized, the other being dicotyledons, or dicots. Monocot seedlings typically have one cotyledon , in contrast to the two cotyledons typical of dicots...

ous herbs, while the Trochilinae prefer dicotyledon

Dicotyledon

The dicotyledons, also known as dicots, are a group of flowering plants whose seed typically has two embryonic leaves or cotyledons. There are around 199,350 species within this group...

ous plant species.

Angraecoid orchids and African moths

Angraecoid orchids

Angraecinae

Angraecinae is a subtribe in the Orchidaceae family. The subtribe consists of approximately 18 nautural genera and about 360 species. The type genus is Angraecum. Most of the genera are endemic to Africa, Madagascar and other Indian Ocean Islands, a few genera can also be found in the...

and African moth

Moth

A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...

s coevolve because the moths are dependent on the flowers for nectar and the flowers are dependent on the moths to spread pollen so they can reproduce. Coevolution has led to deep flowers and moths with long probosci

Proboscis

A proboscis is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In simpler terms, a proboscis is the straw-like mouth found in several varieties of species.-Etymology:...

Old world swallowtail and fringed rue

An example of antagonistic coevolution is the old world swallowtail

Old World Swallowtail

The Old World Swallowtail is a butterfly of the family Papilionidae. The butterfly is also known as the Common Yellow Swallowtail or simply the Swallowtail...

(Papilio machaon) caterpillar living on the fringed rue

Ruta chalepensis

Ruta chalepensis is a species of flowering plant in the citrus family known by the common name fringed rue. It is native to Eurasia and North Africa. It has been found elsewhere as an introduced species. It is a perennial herb growing up to 80 centimeters tall. The leaves are compound, each divided...

(Ruta chalepensis) plant. The rue produces etheric oils which repel plant-eating insects. The old world swallowtail caterpillar developed resistance to these poisonous substances, thus reducing competition with other plant-eating insects.

Garter snake and rough-skinned newt

Coevolution of predator and prey species is illustrated by the Rough-skinned newt

Rough-skinned Newt

The rough-skinned newt is a North American newt known for its strong poison.- Toxicity :Many newts produce toxins to avoid predation, but the toxins of the genus Taricha are particularly potent...

(Taricha granulosa) and the common garter snake

Garter snake

The Garter snake is a Colubrid snake genus common across North America, ranging from Alaska and Canada to Central America. It is the single most widely distributed genus of reptile in North America. The garter snake is also the Massachusettsstate reptile.There is no real consensus on the...

(Thamnophis sirtalis). The newts produce a potent neurotoxin

Neurotoxin

A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...

that concentrates in their skin. Garter snakes have evolved resistance to this toxin through a series of genetic mutation

Mutation

In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...

s, and prey upon the newts. The relationship between these animals has resulted in an evolutionary arms race

Evolutionary arms race

In evolutionary biology, an evolutionary arms race is an evolutionary struggle between competing sets of co-evolving genes that develop adaptations and counter-adaptations against each other, resembling an arms race, which are also examples of positive feedback...

that has driven toxin levels in the newt to extreme levels. This is an example of coevolution because both organisms changed to better increase their chance of survival.

California buckeye and pollinators

When beehives are populated with bee species that have not coevolved with the California buckeye

Aesculus californica

Aesculus californica is a species of buckeye that is native [ |] to California and southwest Oregon [Jackson, County], and the only buckeye native to these states.-Description:...

(Aesculus californica), sensitivity to aesculin

Aesculin

Aesculin, also rendered Æsculin or Esculin, is a glucoside that naturally occurs in the horse chestnut , California Buckeye and in daphnin ....

, a neurotoxin present in its nectar, may be noticed; this sensitivity is only thought to be present in honeybees and other insects that did not coevolve with A. californica.

Acacia ant and bullhorn acacia tree

The acacia ant (Pseudomyrmex ferruginea) protects the bullhorn acacia (Acacia cornigera) from preying insects and from other plants competing for sunlight, and the tree provides nourishment and shelter for the ant and its larvae. Nevertheless, some ant species can exploit trees without reciprocating, and hence have been given various names such as 'cheaters', 'exploiters', 'robbers' and 'freeloaders'. Although cheater ants do important damage to the reproductive organs of trees, their net effect on host fitness is difficult to forecast and not necessarily negative.

Yucca Moth and the yucca plant

In this mutualistic symbiotic relationship, the yucca

Yucca

Yucca is a genus of perennial shrubs and trees in the family Asparagaceae, subfamily Agavoideae. Its 40-50 species are notable for their rosettes of evergreen, tough, sword-shaped leaves and large terminal panicles of white or whitish flowers. They are native to the hot and dry parts of North...

plant (Yucca whipplei) is pollinated exclusively by Tegeticula maculata, a species of yucca moth that in turn relies on the yucca for survival. Yucca moths tend to visit the flowers of only one species of yucca plant. In the flowers, the moth eats the seeds of the plant, while at the same time gathering pollen on special mouth parts. The pollen is very sticky, and will easily remain on the mouth parts when the moth moves to the next flower. The yucca plant also provides a place for the moth to lay its eggs, deep within the flower where they are protected from any potential predators. The adaptations that both species exhibit characterize coevolution because the species have evolved to become dependent on each other.

Mitochondria in eukaryote cells

The existence of mitochondria within eukaryote

Eukaryote

A eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...

cells is an example of coevolution as the mitochondria have a different DNA sequence than that of the nucleus in the host cell.

Coevolution outside biology

Coevolution is primarily a biological concept, but has been applied to other fields by analogy.

Technological coevolution

Computer software

Computer software, or just software, is a collection of computer programs and related data that provide the instructions for telling a computer what to do and how to do it....

and hardware

Computer hardware

Personal computer hardware are component devices which are typically installed into or peripheral to a computer case to create a personal computer upon which system software is installed including a firmware interface such as a BIOS and an operating system which supports application software that...

can be considered as two separate components but tied intrinsically by coevolution. Similarly, operating system

Operating system

An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

s and computer applications

Application software

Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...

, web browser

Web browser

A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...

s and web application

Web application

A web application is an application that is accessed over a network such as the Internet or an intranet. The term may also mean a computer software application that is coded in a browser-supported language and reliant on a common web browser to render the application executable.Web applications are...

s.
All of these systems depend upon each other and advance step by step through a kind of evolutionary process. Changes in hardware, an operating system or web browser may introduce new features that are then incorporated into the corresponding applications running alongside.

Algorithms

Coevolutionary algorithms are a class of algorithms used for generating artificial life

Artificial life

Artificial life is a field of study and an associated art form which examine systems related to life, its processes, and its evolution through simulations using computer models, robotics, and biochemistry. The discipline was named by Christopher Langton, an American computer scientist, in 1986...

as well as for optimization, game learning and machine learning

Machine learning

Machine learning, a branch of artificial intelligence, is a scientific discipline concerned with the design and development of algorithms that allow computers to evolve behaviors based on empirical data, such as from sensor data or databases...

. Coevolutionary methods have been applied by Daniel Hillis, who coevolved sorting networks, and Karl Sims

Karl Sims

Karl Sims is a computer graphics artist and researcher, who is best known for using particle systems and artificial life in computer animation....

, who coevolved virtual creatures.

Cosmology and astronomy

In his book The Self-organizing Universe, Erich Jantsch

Erich Jantsch

Erich Jantsch was an Austrian astrophysicist.In the mid-1960s his increasing concern regarding the future led him to study forecasting techniques...

attributed the entire evolution of the cosmos

Cosmos

In the general sense, a cosmos is an orderly or harmonious system. It originates from the Greek term κόσμος , meaning "order" or "ornament" and is antithetical to the concept of chaos. Today, the word is generally used as a synonym of the word Universe . The word cosmos originates from the same root...

to coevolution.

In astronomy