- Related Topics:
- deceptive coloration
- polychromatism
- pigmentation
- tobiano
- overo
coloration
-
What does coloration mean in biology?
In biology, coloration refers to an organism's general appearance, which depends on the quantity and quality of light reflected from its surfaces. Coloration relies on the distribution and color of biochromes (pigments), the organism's shape, posture, and movement, and the light that strikes it.
Coloration serves many evolutionary functions. Conspicuous coloration can attract or repel other animals. Deceptive coloration can reduce communication to lessen detrimental interactions, and nonoptical functions of coloration can affect an organism's energy budget.
Coloration can be produced physically or chemically. Physical coloration involves submicroscopic structures that split light, while chemical coloration involves natural pigments that reflect portions of the solar spectrum.
3 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
Why do animals and plants have different colors?
Plants and animals exhibit different colors due to a combination of chemical and physical factors.
- Pigments: Plants and animals use natural pigments called biochromes to reflect or transmit portions of the solar spectrum. Common plant pigments include chlorophylls (green) and carotenoids (red, orange, yellow). Animals also have pigments such as melanins (black).
- Structural Coloration: Animals commonly use structural features that refract incident light into its component colors. In plants, this is exemplified by the reflection of white light in some flowers and spectral interference in certain sea plants.
- Genetics: Coloration is largely determined by genetics. Genes control the production and distribution of pigments.
- Environment: Environmental factors, such as ambient light, can also influence coloration.
- Adaptation: Coloration serves various adaptive functions, including camouflage, communication, and attracting mates.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How does coloration help animals survive?
Coloration is central to survival, influencing how animals interact with their environment. It serves optical, visual, and physiological functions, affecting an animal's visibility.
Coloration aids survival through:
- Camouflage: Concealing coloration helps animals blend into their surroundings, avoiding predators.
- Mimicry: Some species mimic others, gaining protection or hunting advantages.
- Warning Coloration: Bright colors warn of danger, like poison, deterring predators; some harmless species mimic these colors for protection.
- Territorial Advertising: Coloration helps in defending territories, with brighter colors intimidating rivals.
- Disruptive Coloration: Patterns disrupt body outlines, confusing predators or concealing movement.
Coloration can both conceal and advertise, crucial for survival and reproduction.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What is camouflage, and how does it relate to coloration?
Camouflage, or concealing coloration, is when animals use biological coloration to hide their location, identity, and movement. It helps them avoid predators or sneak up on prey.
Coloration plays a central role in plants' and animals' lives, even those lacking vision. Camouflage is a type of deceptive coloration where an organism blends into its surroundings. This can involve matching the background color, pattern, or even shape.
Different camouflage techniques include:
* Background matching Resembling the environment in color and form.
* Disruptive coloration Using patterns that disrupt the animal's outline.
* Countershading Darker upper surfaces and lighter lower areas create a uniform appearance.The effectiveness of camouflage depends on the organism's coloration, its background, the lighting, and the visual abilities of the observer.
3 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How do some animals use bright colors to warn predators?
Many animals use bright colors as a warning signal to potential predators, a phenomenon known as aposematism. This biological strategy involves advertising their dangerous or unpalatable nature through easily perceived information, such as striking color patterns.
Common colors include red, black, and yellow, which are easily recognized by many animals. For example, wasps and bees often display black and yellow coloration to warn predators of their stings. Similarly, some snakes with red, orange, or yellow undersides will expose these colors when threatened, signaling their potential danger or distastefulness.
Aposematic coloration benefits both the signaler and the receiver by preventing potentially damaging interactions. Predators learn to associate these colors with unpleasant experiences, avoiding the need for the prey to risk injury from an attack.
5 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What are some ways animals and plants change their coloration over time or in response to the environment?
Animals and plants change coloration over time or in response to the environment in several ways. Many birds and mammals undergo seasonal molts, replacing their plumage or pelage with differently colored feathers or hair. The winter whitening of the willow ptarmigan and varying hare are examples of camouflage that shifts with changes in background coloration.
Coloration changes also occur in populations because of evolutionary pressures. Certain color types have increased odds of surviving and passing on their coloration pattern. A well-documented temporal shift in selection is the industrial melanism of moths in England and Europe, where the proportion of darkly colored individuals has increased dramatically since the 1850s.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
coloration, in biology, the general appearance of an organism as determined by the quality and quantity of light that is reflected or emitted from its surfaces. Coloration depends upon several factors: the colour and distribution of the organismās biochromes (pigments), particularly the relative location of differently coloured areas; the shape, posture, position, and movement of the organism; and the quality and quantity of light striking the organism. The perceived coloration depends also on the visual capabilities of the viewer. Coloration is a dynamic and complex characteristic and must be clearly distinguished from the concept of ācolour,ā which refers only to the spectral qualities of emitted or reflected light.
Many evolutionary functions have been suggested for the effects of coloration on optical signaling. An organism with conspicuous coloration draws attention to itself, with some sort of adaptive interaction the frequent result. Such āadvertisingā coloration may serve to repel or attract other animals. While conspicuous coloration emphasizes optical signals and thereby enhances communication, coloration may, conversely, suppress optical signals or create incorrect signals and thereby reduce communication. This ādeceptiveā coloration serves to lessen detrimental or maladaptive interactions with other organisms.
Coloration may also affect an organism in ways other than its interaction with other organisms. Such nonoptical functions of coloration include physiological roles that depend on the molecular properties (e.g., strength and type of chemical bonds) of the chemicals that create colour. For example, dark hair is mechanically stronger than light hair, and dark feathers resist abrasion better than light feathers. Coloration may also play a part in the organismās energy budget, because biochromes create colour by the differential reflection and absorption of solar engery. Energy absorbed as a result of coloration may be used in biochemical reactions, such as photosynthesis, or it may contribute to the thermal equilibrium of the organism. Nonoptical functions of coloration also include visual functions in which coloration or its pattern affects an animalās own vision. Surfaces near the eye may be darkly coloured, for instance, to reduce reflectance that interferes with vision.
" height="20" alt="HEW Logo">
Emitted light, the product of bioluminescence, forms a portion of the coloration of some organisms. Bioluminescence may reveal an organism to nearby animals, but it may also serve as a light source in nocturnal species or in deepwater marine animals such as the pinecone fishes (Monocentris). These fishes feed at night and have bright photophores, or bioluminescent organs, at the tips of their lower jaws; they appear to use these organs much like tiny searchlights as they feed on planktonic (minute floating) organisms.
Because many pigments are formed as the natural or only slightly modified by-products of metabolic processes, some coloration may be without adaptive function. Nonfunctional coloration can, for example, be an incidental effect of a pleiotropic gene (a gene that has multiple effects), or it can result from pharmacological reaction (as when the skin of a Caucasian person turns blue in cold water) or from pure chance. It seems unlikely, however, that any apparently fortuitous coloration could long escape the process of natural selection and thus remain totally without function.
Regardless of its adaptive advantages, a particular coloration or pattern of coloration cannot evolve unless it is within the speciesā natural pool of genetic variability. Thus a species may lack a seemingly adaptive coloration because genetic variability has not included that coloration or pattern in its hereditary repertoire.
Because humans are highly visual animals, we are naturally interested in and attentive to biological coloration. Human attention to coloration ranges from the purely aesthetic to the rigidly pragmatic. Soft, pastel colorations aid in increasing work efficiency and contribute to tranquil moods; bright, strongly contrasting colours seem to contribute to excitement and enthusiasm. These phenomena may be extensions of the basic human response to the soft blue, green, and brown backgrounds of the environment as opposed to sharply contrasting warning colorations found on many dangerous organisms. It is possible that much of the aesthetic value humans attach to coloration is closely related to its broad biological functions.
The trusted destination for professionals, college students, and lifelong learners.
SUBSCRIBE
Human interest in coloration has led to biological studies. The classical work by the Moravian abbot Gregor Mendel on inherited characteristics, based largely on plant coloration, formed the foundation for modern genetics. Coloration also aids in the identification of organisms. It is an easily perceived, described, and compared characteristic. Related species living in different habitats, however, frequently have strikingly different colorations. Since coloration is susceptible to alteration in various functional contexts, it usually lacks value as a conservative characteristic for determining systematic relationships between all but the most closely related species.
Related articles of interest include animal behaviour; mimicry.
Structural and biochemical bases for colour
Organisms produce colour physically, by submicroscopic structures that fractionate incident light into its component colours (schemochromes); or chemically, by natural pigments (biochromes) that reflect or transmit (or both) portions of the solar spectrum. Pigmentary colours, being of molecular origin, may be expressed independently of structural colour and are not altered by crushing, grinding, or compression. Structural colours are often reinforced by the presence of biochromes and are altered or destroyed by crushing, grinding, or compression.
Structural colours (schemochromes)
The physical principles of total reflection, spectral interference, scattering, and, to some extent, polychromatic diffraction, all familiar in reference to inanimate objects, are also encountered among tissues of living forms, most commonly in animals. In plants these physical principles are exemplified only by the total reflection of white light by some fungi and bacteria and by the petals of some flowers and barks, and by some spectral interference in certain sea plants.
Reflection
Total reflection of lightāwhich imparts whiteness to flowers, birdsā feathers, mammalian hair, and the wings of certain butterfliesāoften results from the separation of finely divided materials by minute air spaces. Secretions or deposits in tissues may also contribute to the whiteness; for example, the fat and protein in mammalian milk and the calcium carbonate in the shells of mollusks, crustaceans, certain echinoderms, corals, and protozoans.