NationMaster - Encyclopedia: Peppered moth

The peppered moth (Biston betularia) is a temperate species of night-flying moth often used by educators as an example of natural selection. A nocturnal animal is one that sleeps during the day and is active at night - the opposite of the human (diurnal) schedule. ... A moth is an insect closely related to the butterfly. ... The GalÃ¡pagos Islands hold 13 species of finches that are closely related and differ most markedly in the shape of their beaks. ...

Ecology and life cycle

In Britain, the peppered moth is univoltine (i.e. it has one generation per year), whilst in south-eastern North America it is bivoltine (two generations per year). The lepidopteran life cycle consists of four stages: ova (eggs), several larval instars (caterpillars), pupae, which overwinter in the soil, and imagines (adults). During the day, the moths cryptically rest on trees, where they are preyed on by birds. Voltinism is a term used in biology to indicate the number of broods or generations of an organisms in a year. ... Superfamilies Butterflies Hesperioidea Papilionoidea Moths Acanthopteroctetoidea Alucitoidea Axioidea Bombycoidea Calliduloidea Choreutoidea Cossoidea Drepanoidea Epermenioidea Eriocranioidea Galacticoidea Gelechioidea Geometroidea Gracillarioidea Hedyloidea Hepialoidea Heterobathmioidea Hyblaeoidea Immoidea Incurvarioidea Lasiocampoidea Lophocoronoidea Micropterigoidea Mimallonoidea Mnesarchaeoidea Neopseustoidea Nepticuloidea Noctuoidea Palaephatoidea Pterophoroidea Pyraloidea Schreckensteinioidea Sesioidea Simaethistoidea Thyridoidea Tineoidea Tischerioidea Tortricoidea Urodoidea Whalleyanoidea Yponomeutoidea Zygaenoidea The order Lepidoptera... A life cycle is a period involving one generation of an organism through means of reproduction, whether through asexual reproduction or sexual reproduction. ... A larva (Latin; plural larvae) is a juvenile form of animal with indirect development, undergoing metamorphosis (for example, insects or amphibians). ... An instar is a developmental stage of arthropods, such as insects, between each molt. ... The striking caterpillar of the Emperor Gum Moth A caterpillar is the larval form of a lepidopteran (a member of the insect order comprised of butterflies and moths). ... Chrysalis of Gulf Fritillary in Georgetown, South Carolina Pupation of Inachis io A pupa (plural: pupae or pupas) is the life stage of some insects undergoing transformation. ... The imago is the last stage of development of an insect, after the last ecdysis of an incomplete metamorphosis, or after emergence from pupation where the metamorphosis is complete. ...

The caterpillar is a twig mimic, varying in colour between green and brown. It goes into the soil late in the season, where it pupates in order to spend the winter. The imagines emerge from the pupae between late May and August, the males slightly before the females (this is common and expected from sexual selection). They emerge late in the day and dry their wings before flying that night. A mimic is any species that has evolved to appear similar to another successful species in order to dupe predators into avoiding the mimic, or dupe prey into approaching the mimic. ... Illustration from The Descent of Man and Selection in Relation to Sex by Charles Darwin showing the Tufted Coquette Lophornis ornatus, female on left, ornamented male on right. ...

The males fly every night of their lives in search of females, whereas the females release pheromones to attract males, only flying on the first night. Since the pheromone is carried by the wind, males tend to travel up the concentration gradient, i.e., towards the source. During flight, they are subject to predation by bats. The males guard the female from other males until she lays the eggs. The female lays about 2,000 pale-green ovoid eggs about 1 mm in length into crevices in bark with her ovipositor. Fanning honeybee exposes Nasonov gland (white-at tip of abdomen) releasing pheromone to entice swarm into an empty hive A pheromone is any chemical or set of chemicals produced by a living organism that transmits a message to other members of the same species. ... A concentration gradient is the difference in density of a substance over a distance. ... Suborders Megachiroptera Microchiroptera See text for families. ... The ovipositor is an organ used by some of the arthropods for oviposition, i. ...

Resting behaviour

A mating pair or a lone individual will spend the day hiding from predators, particularly birds. In the case of the former, the male stays with the female to ensure paternity. The best evidence for resting positions is given by data collected by the peppered moth researcher Michael Majerus, and it is given in the accompanying charts. These data were originally published in Howlett and Majerus (1987), and an updated version published in Majerus (1998), who concluded that the moths rest in the upper part of the trees. Majerus notes: Image File history File links Peppered_moth_resting_positions_1964-2000. ... Image File history File links Peppered_moth_resting_positions_1964-2000. ... Image File history File links Peppered_moth_resting_positions_2001-2003. ... Image File history File links Peppered_moth_resting_positions_2001-2003. ... Dr. Michael E. N. Majerus (born 1954) is a geneticist at the University of Cambridge, and the author of several books. ...

From their original data, Howlett and Majerus (1987) concluded that peppered moths generally rest in unexposed positions, using three main types of site. Firstly, a few inches below the a branch-trunk joint on a tree trunk where the moth is in shadow; secondly, on the underside of branches and thirdly on foliate twigs. The above data would appear to support this.

Further support for these resting positions are given from experiments watching captive moths taking up resting positions in both males (Mikkola, 1979; 1984) and females (Liebert and Brakefield, 1987).

Majerus et al (2000) have shown that peppered moths are cryptically camouflaged against their backgrounds when they rest in the boughs of trees. It is clear that in human visible wavelengths, typica are camouflaged against lichens and carbonaria against plain bark. However, birds are capable of seeing ultraviolet light that humans cannot see. Using an ultraviolet-sensitive video camera, Majerus et al showed that typica reflect ultraviolet light in a speckled fashion and are camouflaged against crustose lichens common on branches, both in ultraviolet and human-visible wavelengths. However, typica are not as well camouflaged against foliose lichens common on tree trunks; though they are camouflaged in human wavelengths, in ultraviolet wavelengths, foliose lichens do not reflect ultraviolet light. The wavelength is the distance between repeating units of a wave pattern. ... To meet Wikipedias quality standards, the use of images on this page may require cleanup, involving adjustment of image placement, formatting, size, or other adjustments. ... For other meanings of bark, see Bark (disambiguation). ... The solar corona as seen in deep ultraviolet light at 17. ...

Morphs

There are several melanic and non-melanic morphs of the peppered moth. A particular morph can be indicated in a standard way by following the species name in the form "morpha morph name". In Britain, the typical white speckled morph is known as morpha typica, the melanic morph is morpha carbonaria, and the intermediate phenotype is morpha insularia. These are controlled genetically. In biology, polymorphism can be defined as the occurrence in the same habitat of two or more forms of a trait in such frequencies that the rarer cannot be maintained by recurrent mutation alone. ... Melanistic Eastern Grey Squirrel in Toronto, Canada. ... A Morph, meaning form (from the Latin morpha), is a zoological term that descibes local populations or subpopulations of a single species of animal that may or may not be phenotypically distinct from the larger population as a whole. ... Individuals in the mollusk species Donax variabilis show diverse coloration and patterning in their phenotypes. ...

At present, the molecular genetics and biochemistry of the melanism in this species remains unknown. True (2003) has reviewed this and suggests work based on candidate genes from other insects such as the fruit fly, Drosophila melanogaster. Molecular genetics is the field of biology which studies the structure and function of genes at a molecular level. ... Biochemistry is the study of the chemical processes and transformations in living organisms. ... A candidate gene is a gene, located in a chromosome region suspected of being involved in a disease, whose protein product suggests that it could be the disease gene in question. ... Binomial name Drosophila melanogaster Meigen, 1830 [1] Drosophila melanogaster (from the Greek for black-bellied dew-lover) is a two-winged insect that belongs to the Diptera, the order of the flies. ...

It is a common mistake to confuse the name of the morph with that of the species or subspecies, hence mistakes such as "Biston carbonaria" and "Biston betularia carbonaria". This might lead to the erroneous belief that speciation was involved in the observed evolution of the peppered moth. This is not the case; individuals of each morph can breed and produce fertile offspring with individuals of all other morphs; hence there is only one peppered moth species. In biology, a species is one of the basic units of biodiversity. ... In zoology, as in other branches of biology, subspecies is the rank immediately subordinate to a species. ... Charles Darwins first sketch of an evolutionary tree from his First Notebook on Transmutation of Species (1837) Speciation is the evolutionary process by which new biological species arise. ...

In Europe, there are three morphs: morpha typica, the typical white morph (also known as "morpha betularia"), morpha carbonaria, the melanic black morph (also previously known as "morpha doubledayaria"), and morpha medionigra, an intermediate semi-melanic morph. European breeding experiments have shown that in Biston betularia betularia, the allele for melanism producing morpha carbonaria is controlled by a single locus. The melanic allele is dominant to the non-melanic allele. This situation is, however, somewhat complicated by the presence of three other alleles that produce indistinguishable morphs of morpha medionigra. These are of intermediate dominance, but this is not complete (Majerus, 1998). In genetics, an allele (pronounced al-eel or al-e-ul) is any one of a number of viable DNA codings occupying a given locus (position) on a chromosome. ... Short and long arms Chromosome. ...

In North America, the the melanic black morph is morpha swettaria. In Biston betularia cognataria, the melanic allele (producing morpha swettaria) is similarly dominant to the non-melanic allele. There are also some intermediate morphs. In Japan, no melanic morphs have been recorded; they are all morpha f. typica.

Evolution

The evolution of the peppered moth over the last two hundred years has been studied in detail. Originally, the vast majority of peppered moths had light coloration, which effectively camouflaged them against the light-colored trees and lichens which they rested upon. However, due to widespread pollution during the Industrial Revolution in England, many of the lichens died out, and the trees which peppered moths rested on became blackened by soot, causing most of the light-colored moths, or typica, to die off due to predation. At the same time, the dark-colored, or melanic, moths, carbonaria, flourished because of their ability to hide on the darkened trees.^[1] , the white-bodied peppered moth. ... Image File history File linksMetadata Download high-resolution version (3000x2000, 1318 KB) Description: Biston betularia Source: picture taken by Olaf Leillinger at 2006-06-14 License: CC-BY-SA-2. ... Image File history File linksMetadata Download high-resolution version (3000x2000, 1318 KB) Description: Biston betularia Source: picture taken by Olaf Leillinger at 2006-06-14 License: CC-BY-SA-2. ... Image File history File linksMetadata Download high-resolution version (3000x2000, 1001 KB) Description: (Linnaeus, 1758) Source: picture taken by Olaf Leillinger at 2006-06-13 License: CC-BY-SA-2. ... Image File history File linksMetadata Download high-resolution version (3000x2000, 1001 KB) Description: (Linnaeus, 1758) Source: picture taken by Olaf Leillinger at 2006-06-13 License: CC-BY-SA-2. ... An infant Cuttlefish blends into the surrounding sand substrate. ... A Watt steam engine. ... Soot, also called lampblack, Pigment Black 7, carbon black or black carbon, is a dark powdery deposit of unburned fuel residues, usually composed mainly of amorphous carbon, that accumulates in chimneys, automobile mufflers and other surfaces exposed to smokeâ€”especially from the combustion of carbon-rich organic fuels in the...

Since then, with improved environmental standards, light-colored peppered moths have again become common, but the dramatic change in the peppered moth's population has remained a subject of much interest and study, and has led to the coining of the term "industrial melanism" to refer to the genetic darkening of species in response to pollutants. As a result of the relatively simple and easy-to-understand circumstances of the adaptation, the peppered moth has become a common example used in explaining or demonstrating natural selection to laypeople and classroom students.^[2] The GalÃ¡pagos Islands hold 13 species of finches that are closely related and differ most markedly in the shape of their beaks. ...

The first carbonaria morph was recorded by Edleston in Manchester in 1848, and over the subsequent years it increased in frequency. Predation experiments, particularly by Bernard Kettlewell, established that the agent of selection was birds who preyed on the morpha carbonaria morph. Dr Henry Bernard Davis Kettlewell (24 February 1907 - 1979) was a British lepidopterist and medical doctor. ...

Creationists such as Jonathan Wells have criticized the use of peppered moth melanism as an example of evolution in action. Wells alleges that peppered moth studies, and in particular Kettlewell's experiments, were erroneous and fraudulent in his book Icons of Evolution. However, although various errors and oversights have been found in early experiments on peppered moth evolution, subsequent experiments and observations have confirmed the phenomenon and its initial explanation.^[3]^[4]^[5] The Creation of Light by Gustave DorÃ©. Creation refers to the concept that all humanity, life, the Earth, or the universe as a whole was created by a deity (often referred to as God). ... Jonathan Wells John Corrigan Jonathan Wells is an author, a prominent promoter of intelligent design and an opponent of evolution, which Wells and other intelligent design proponents often refer to as Darwinism. ... Icons of Evolution, Science or Myth? is a controversial book by the Intelligent Design advocate and fellow of the Discovery Institute, Jonathan Wells, and a 2002 video about the book. ...

Contents

Ecology and life cycle

Resting behaviour

Morphs

Evolution

Further reading

References

External links

Contents

Ecology and life cycle GA_googleFillSlot("encyclopedia_square");

Resting behaviour

Morphs

Evolution

Further reading

References

External links

Ecology and life cycle