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The evolution of the peppered moth is an
evolutionary 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. Variation t ...
instance of directional colour change in the moth population as a consequence of air pollution during the
Industrial Revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
. The frequency of dark-coloured moths increased at that time, an example of
industrial melanism Industrial melanism is an evolutionary effect prominent in several arthropods, where dark pigmentation (melanism) has evolved in an environment affected by industrial pollution, including sulphur dioxide gas and dark soot deposits. Sulphur dioxi ...
. Later, when pollution was reduced, the light-coloured form again predominated. Industrial melanism in the
peppered moth The peppered moth (''Biston betularia'') is a temperate species of night-flying moth. It is mostly found in the northern hemisphere in places like Asia, Europe and North America. Peppered moth evolution is an example of population genetics a ...
was an early test of
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 fr ...
's
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. Charl ...
in action, and it remains a classic example in the teaching of evolution. In 1978,
Sewall Wright Sewall Green Wright FRS(For) Honorary FRSE (December 21, 1889March 3, 1988) was an American geneticist known for his influential work on evolutionary theory and also for his work on path analysis. He was a founder of population genetics alongsi ...
described it as "the clearest case in which a conspicuous evolutionary process has actually been observed." The dark-coloured or ''melanic'' form of the peppered moth (var. ''carbonaria'') was rare, though a specimen had been collected by 1811. After field collection in 1848 from
Manchester Manchester () is a city in Greater Manchester, England. It had a population of 552,000 in 2021. It is bordered by the Cheshire Plain to the south, the Pennines to the north and east, and the neighbouring city of Salford to the west. The tw ...
, an industrial city in England, the frequency of the variety was found to have increased drastically. By the end of the 19th century it almost completely outnumbered the original light-coloured type (var. ''typica''), with a record of 98% in 1895. The evolutionary importance of the moth was only speculated upon during Darwin's lifetime. It was 14 years after Darwin's death, in 1896, that J. W. Tutt presented it as a case of natural selection. Because of this, the idea spread widely, and more people came to believe in Darwin's theory. Bernard Kettlewell was the first to investigate the evolutionary mechanism behind peppered moth adaptation, between 1953 and 1956. He found that a light-coloured body was an effective
camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...
in a clean environment, such as in rural
Dorset Dorset ( ; archaically: Dorsetshire , ) is a county in South West England on the English Channel coast. The ceremonial county comprises the unitary authority areas of Bournemouth, Christchurch and Poole and Dorset. Covering an area of , Do ...
, while the dark colour was beneficial in a polluted environment like industrial
Birmingham Birmingham ( ) is a city and metropolitan borough in the metropolitan county of West Midlands in England. It is the second-largest city in the United Kingdom with a population of 1.145 million in the city proper, 2.92 million in the West ...
. This selective survival was due to birds, which easily caught dark moths on clean trees and white moths on trees darkened with soot. The story, supported by Kettlewell's experiment, became the canonical example of
Darwinian Darwinism is a theory of biological evolution developed by the English naturalist Charles Darwin (1809–1882) and others, stating that all species of organisms arise and develop through the natural selection of small, inherited variations that ...
evolution and evidence for natural selection used in standard textbooks. However, failure to replicate the experiment and Theodore David Sargent's criticism of Kettlewell's methods in the late 1960s led to general skepticism. When Judith Hooper's '' Of Moths and Men'' was published in 2002, Kettlewell's story was more sternly attacked, and accused of fraud. The criticism became a major argument for
creationists Creationism is the religious belief that nature, and aspects such as the universe, Earth, life, and humans, originated with supernatural acts of divine creation. Gunn 2004, p. 9, "The ''Concise Oxford Dictionary'' says that creationism is 'th ...
. Michael Majerus was the principal defender. His seven-year experiment beginning in 2001, the most elaborate of its kind in
population biology The term population biology has been used with different meanings. In 1971 Edward O. Wilson ''et al''. used the term in the sense of applying mathematical models to population genetics, community ecology, and population dynamics. Alan Hastings u ...
, the results of which were published posthumously in 2012, vindicated Kettlewell's work in great detail. This restored peppered moth evolution as "the most direct evidence", and "one of the clearest and most easily understood examples of Darwinian evolution in action".


Origin and evolution

Before the
Industrial Revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
, the black form of the peppered moth was rare. The first black specimen (of unknown origin) was collected before 1811, and kept in the
University of Oxford , mottoeng = The Lord is my light , established = , endowment = £6.1 billion (including colleges) (2019) , budget = £2.145 billion (2019–20) , chancellor ...
. The first live specimen was caught by R. S. Edleston in
Manchester Manchester () is a city in Greater Manchester, England. It had a population of 552,000 in 2021. It is bordered by the Cheshire Plain to the south, the Pennines to the north and east, and the neighbouring city of Salford to the west. The tw ...
, England in 1848, but he reported this only 16 years later in 1864, in ''
The Entomologist The ''Entomological Magazine'' is a publication devoted to entomology. The ''Entomological Magazine'' was published between September 1832 and October 1838 by the Society of Entomologists of London. The editor was Edward Newman aided by Fran ...
''. Edleston notes that by 1864 it was the more common type of moth in his garden in Manchester. The light-bodied moths were able to blend in with the light-coloured
lichens A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship. During the early decades of the Industrial Revolution in England, the countryside between London and Manchester became blanketed with
soot Soot ( ) is a mass of impure carbon particles resulting from the incomplete combustion of hydrocarbons. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolysed ...
from the new coal-burning factories. Many of the light-bodied lichens died from
sulphur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic ac ...
emissions, and the trees became darkened. This led to an increase in bird predation for light-coloured moths, as they no longer blended in as well in their
polluted Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...
ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...
: indeed, their bodies now dramatically contrasted with the colour of the bark. Dark-coloured moths, on the other hand, were
camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...
d very well by the blackened trees.Miller, Ken (1999).
The Peppered Moth: An Update
'
The population of dark-coloured moth rapidly increased. By the mid-19th century, the number of dark-coloured moths had risen noticeably, and by 1895, the percentage of dark-coloured moths in Manchester was reported at 98%, a dramatic change (of almost 100%) from the original frequency. This effect of industrialization in body colour led to the coining of the term "
industrial melanism Industrial melanism is an evolutionary effect prominent in several arthropods, where dark pigmentation (melanism) has evolved in an environment affected by industrial pollution, including sulphur dioxide gas and dark soot deposits. Sulphur dioxi ...
". The implication that industrial melanism could be evidence supporting
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 fr ...
's theory of
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. Charl ...
was noticed during his lifetime. Albert Brydges Farn (1841–1921), a British entomologist, wrote to Darwin on 18 November 1878 to discuss his observation of colour variations in the Annulet moth (then ''Gnophos obscurata'', now '' Charissa obscurata''). He noted the existence of dark moths in peat in the
New Forest The New Forest is one of the largest remaining tracts of unenclosed pasture land, heathland and forest in Southern England, covering southwest Hampshire and southeast Wiltshire. It was proclaimed a royal forest by William the Conqueror, featu ...
, brown moths on clay and red soil in
Herefordshire Herefordshire () is a county in the West Midlands of England, governed by Herefordshire Council. It is bordered by Shropshire to the north, Worcestershire to the east, Gloucestershire to the south-east, and the Welsh counties of Monmouthsh ...
, and white moths on chalk cliffs in
Lewes Lewes () is the county town of East Sussex, England. It is the police and judicial centre for all of Sussex and is home to Sussex Police, East Sussex Fire & Rescue Service, Lewes Crown Court and HMP Lewes. The civil parish is the centre of t ...
, and suggested that this variation was an example of "survival of the fittest". He told Darwin that he had found dark moths on a chalk slope where the foliage had been blackened by smoke from
lime kiln A lime kiln is a kiln used for the calcination of limestone ( calcium carbonate) to produce the form of lime called quicklime ( calcium oxide). The chemical equation for this reaction is : CaCO3 + heat → CaO + CO2 This reaction can take ...
s, and he had also heard that white moths had become less common at Lewes after lime kilns had been in operation for a few years. Darwin does not seem to have responded to this information, possibly because he thought natural selection would be a much slower process. A scientific explanation of moth coloration was only published in 1896, 14 years after Darwin's death, when J. W. Tutt explicitly linked peppered moth melanism to natural selection.


Rise and fall of phenotype frequency

Melanism The term melanism refers to black pigment and is derived from the gr, μελανός. Melanism is the increased development of the dark-colored pigment melanin in the skin or hair. Pseudomelanism, also called abundism, is another variant of p ...
has appeared in both European and North American peppered moth populations. Information about the rise in frequency is scarce. Much more is known about the subsequent fall in
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 prope ...
frequency, as it has been measured by
lepidopterist Lepidopterology ()) is a branch of entomology concerning the scientific study of moths and the three superfamilies of butterflies. Someone who studies in this field is a lepidopterist or, archaically, an aurelian. Origins Post-Renaissance, the ...
s using moth traps. Steward compiled data for the first recordings of the peppered moth by locality, and deduced that the ''carbonaria'' morph was the result of a single
mutation In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitos ...
that subsequently spread. By 1895, it had reached a reported frequency of 98% in Manchester. From around 1962 to the present, the phenotype frequency of ''carbonaria'' has steadily fallen in line with cleaner air around industrial cities. Its decline has been measured more accurately than its rise, through more rigorous scientific studies. Notably, Kettlewell conducted a national survey in 1956, Bruce Grant conducted a similar one in early 1996, and L.M. Cook in 2003. Similar results were found in North America. Melanic forms have not been found in Japan. It is believed that this is because peppered moths in Japan do not inhabit industrialised regions.


Genetics

Tutt was the first to propose the "differential bird predation hypothesis" in 1896, as a mechanism of
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. Charl ...
. The melanic morphs were better camouflaged against the bark of trees without foliose lichen, whereas the ''typica'' morphs were better camouflaged against trees with lichens. As a result, birds would find and eat those morphs that were not camouflaged with increased frequency. In 1924, J.B.S. Haldane calculated, using a simple general selection model, the selective advantage necessary for the recorded natural evolution of peppered moths, based on the assumption that in 1848 the frequency of dark-coloured moths was 2%, and by 1895 it was 95%. The dark-coloured, or melanic, form would have had to be 50% more fit than the typical, light-coloured form. Even taking into consideration possible errors in the model, this reasonably excluded the
stochastic Stochastic (, ) refers to the property of being well described by a random probability distribution. Although stochasticity and randomness are distinct in that the former refers to a modeling approach and the latter refers to phenomena themselve ...
process of genetic drift, because the changes were too fast. Haldane, J.B.S. (1924). '' A Mathematical Theory of Natural and Artificial Selection''. Haldane's statistical analysis of selection for the melanic variant in peppered moths became a well known part of his effort to demonstrate that mathematical models that combined natural selection with Mendelian genetics could explain evolution – an effort that played a key role in the foundation of the discipline of
population genetics Population genetics is a subfield of genetics that deals with genetic differences within and between populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as adaptation, speciation, and pop ...
, and the beginnings of the
modern synthesis Modern synthesis or modern evolutionary synthesis refers to several perspectives on evolutionary biology, namely: * Modern synthesis (20th century), the term coined by Julian Huxley in 1942 to denote the synthesis between Mendelian genetics and s ...
of evolutionary theory with genetics. The peppered moth ''Biston betularia'' is also a model of
parallel evolution Parallel evolution is the similar development of a trait in distinct species that are not closely related, but share a similar original trait in response to similar evolutionary pressure.Zhang, J. and Kumar, S. 1997Detection of convergent and paral ...
in the incidence of melanism in the British form (''f. carbonaria'') and the American form (''f. swettaria'') as they are indistinguishable in appearance. Genetic analysis indicates that both phenotypes are inherited as
autosomal dominant In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and ...
s. Cross hybridizations indicate that the phenotypes are produced by alleles at a single locus. The gene for ''carbonaria'' in ''B. betularia'' was thought to be in a region of chromosome 17. It was later concluded that the gene could not be in that region, because none of the genes in the chromosome coded for either wing pattern or melanisation. The region that was used to find it was the first intron of the orthologue of the ''cortex'' gene in ''Drosophila''. Through elimination of candidates within the region based on rarity, a 21,925 base pair insert remained. The insert, labelled ''carb''-TE, is a class II
transposable element A transposable element (TE, transposon, or jumping gene) is a nucleic acid sequence in DNA that can change its position within a genome, sometimes creating or reversing mutations and altering the cell's genetic identity and genome size. Trans ...
that has an approximately 9-kb non-repetitive sequence tandemly repeated two and one third times. There are 6 base pairs of inverted repeats and duplicated 4 base pairs at the target site not present in ''typica'' moths. ''Carb-''TE has higher expression during the stage of rapid wing disc morphogenesis. The mechanism of how the gene increases expression, and whether it is the only gene involved, is still not known.


Alternative hypotheses

Several alternative hypotheses to natural selection as the driving force of evolution were proposed during the 1920s and 1930s. Random mutation,
migration Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...
or
genetic drift Genetic drift, also known as allelic drift or the Wright effect, is the change in the frequency of an existing gene variant (allele) in a population due to random chance. Genetic drift may cause gene variants to disappear completely and there ...
were also seen as major forces of evolution. P. A. Riley proposed an additional selective factor, where heavy metal
chelation Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom. These ligands are ...
by melanin would supposedly protect peppered moths against the toxic effects of heavy metals associated with industrialisation. This selective advantage would supplement the major selective mechanism of differential bird predation.


Phenotypic induction

In 1920, John William Heslop-Harrison rejected Tutt's differential bird predation hypothesis, on the basis that he did not believe that birds ate moths. Instead he proposed that pollutants could cause changes to the soma and
germ plasm Germ plasm () is a biological concept developed in the 19th century by the German biologist August Weismann. It states that heritable information is transmitted only by germ cells in the gonads (ovaries and testes), not by somatic cells. The r ...
of the organism. In 1925, K. Hasebroek made an early attempt to prove this hypothesis, exposing pupae to pollutant gases, namely hydrogen sulfide (H2S),
ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous wa ...
(NH3) and " pyredin". He used eight species in his studies, four of which were species of butterfly that did not exhibit melanism. In 1926 and 1928, Heslop-Harrison suggested that the increase of melanic moths in industrialised regions was due to "
mutation pressure Mutationism is one of several alternatives to evolution by natural selection that have existed both before and after the publication of Charles Darwin's 1859 book ''On the Origin of Species''. In the theory, mutation was the source of novelty, cr ...
", not to selection by predators which he regarded as negligible. Salts of
lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, l ...
and
manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy u ...
were present in the airborne pollutant particles, and he suggested that these caused the mutation of genes for melanin production but of no others. He used ''Selenia bilunaria'' and ''Tephrosia bistortata'' as material. The larvae were fed with leaves that had incorporated these salts: melanics subsequently appeared. A similar experiment in 1932 by McKenney Hughes failed to replicate these results; the statistician and geneticist
Ronald Fisher Sir Ronald Aylmer Fisher (17 February 1890 – 29 July 1962) was a British polymath who was active as a mathematician, statistician, biologist, geneticist, and academic. For his work in statistics, he has been described as "a genius who ...
showed that Heslop-Harrison's controls were inadequate, and that Hughes's findings made the 6% mutation rate required by Heslop-Harrison "improbable".


Kettlewell's experiment

The first important experiments on the peppered moth were carried out by Bernard Kettlewell at Oxford University, under the supervision of E. B. Ford, who helped him gain a grant from the
Nuffield Foundation The Nuffield Foundation is a charitable trust established in 1943 by William Morris, Lord Nuffield, the founder of Morris Motors Ltd. It aims to improve social well-being by funding research and innovation projects in education and social pol ...
to perform the experiments. In 1953, Kettlewell started a preliminary experiment in which moths were released into a large (18m × 6m)
aviary An aviary is a large enclosure for confining birds, although bats may also be considered for display. Unlike birdcages, aviaries allow birds a larger living space where Bird flight, they can fly; hence, aviaries are also sometimes known as fligh ...
, where they were fed on by
great tit The great tit (''Parus major'') is a passerine bird in the tit family Paridae. It is a widespread and common species throughout Europe, the Middle East, Central Asia and east across the Palearctic to the Amur River, south to parts of North Af ...
s (''Parus major''). His main experiment, at Christopher Cadbury Wetland Reserve in
Birmingham Birmingham ( ) is a city and metropolitan borough in the metropolitan county of West Midlands in England. It is the second-largest city in the United Kingdom with a population of 1.145 million in the city proper, 2.92 million in the West ...
, England, involved marking, releasing and recapturing marked moths. He found that in this polluted woodland ''typica'' moths were preferentially preyed upon. He thus showed that the melanic phenotype was important to the survival of peppered moths in such a habitat. Kettlewell repeated the experiment in 1955 in unpolluted woodlands in
Dorset Dorset ( ; archaically: Dorsetshire , ) is a county in South West England on the English Channel coast. The ceremonial county comprises the unitary authority areas of Bournemouth, Christchurch and Poole and Dorset. Covering an area of , Do ...
, and again in the polluted woods in Birmingham. In 1956 he repeated the experiments and found similar results; in Birmingham, birds ate most of the white moths (75%), whereas in Dorset, most of the dark moths (86%) were eaten.


Criticisms

Theodore David Sargent performed experiments between 1965 and 1969, from which he concluded that it was not possible to reproduce Kettlewell's results, and said that birds showed no preference for moths on either black or white tree trunks. He suggested that Kettlewell had trained the birds to pick moths on tree trunks to obtain the desired results. Two chapters in Michael Majerus's 1998 book '' Melanism: Evolution in Action'' critiqued the research in Kettlewell's '' The Evolution of Melanism'', discussed studies which raised questions about Kettlewell's original experimental methods, and called for further research. Reviewing the book,
Jerry Coyne Jerry may refer to: Animals * Jerry (Grand National winner), racehorse, winner of the 1840 Grand National * Jerry (St Leger winner), racehorse, winner of 1824 St Leger Stakes Arts, entertainment, and media * ''Jerry'' (film), a 2006 Indian film ...
noted these points, and concluded that "for the time being we must discard ''Biston'' as a well-understood example of natural selection in action, although it is clearly a case of evolution. There are many studies more appropriate for use in the classroom." Judith Hooper's book '' Of Moths and Men'' (2002) severely criticised Kettlewell's experiment. Hooper argued that Kettlewell's field notes could not be found and suggested that his experiment was fraudulent, on the basis of Sargent's criticisms alleging that the photographs of the moths were taken of dead moths placed on a log. She said that E. B. Ford was a "Darwinian zealot", and claimed that he exploited the scientifically naive Kettlewell to obtain the desired experimental results. The book's reception led to demands that the peppered moth evolution story be deleted from textbooks. Scientists have examined the allegations made by Hooper, and found them to be without merit. Phillip E. Johnson, a co-founder of the creationist
intelligent design Intelligent design (ID) is a pseudoscientific argument for the existence of God, presented by its proponents as "an evidence-based scientific theory about life's origins". Numbers 2006, p. 373; " Dcaptured headlines for its bold attempt t ...
movement, said that the moths "do not sit on tree trunks", that "moths had to be glued to the trunks" for pictures, and that the experiments were "fraudulent" and a "scam." The intelligent design advocate Jonathan Wells wrote an essay on the subject, a shortened version of which appeared in the 24 May 1999 issue of '' The Scientist'', claiming that "The fact that peppered moths do not normally rest on tree trunks invalidates Kettlewell's experiments". Wells further wrote in his 2000 book '' Icons of Evolution'' that "What the textbooks don't explain, however, is that biologists have known since the 1980s that the classical story has some serious flaws. The most serious is that peppered moths in the wild don't even rest on tree trunks. The textbook photographs, it turns out, have been staged."Wells J. (2000). '' Icons of Evolution: Science or Myth? Why Much of What We Teach About Evolution is Wrong''. Regnery Press, Washington, D.C., p. 138 (book available fro
Iconsofevolution.com
However, peppered moths do rest on tree trunks on occasion, and
Nick Matzke Nicholas J. Matzke is the former Public Information Project Director at the National Center for Science Education (NCSE) and served an instrumental role in NCSE's preparation for the 2005 '' Kitzmiller v. Dover Area School District'' trial. One of ...
states that there is little difference between the 'staged' photos and 'unstaged' ones.


Majerus's experiment

From 2001 to 2007, Majerus carried out experiments in Cambridge to resolve the various criticisms of Kettlewell's experiment. During his experiment, he noted the natural resting positions of peppered moths. Of the 135 moths examined, over half were on tree branches, mostly on the lower half of the branch; 37% were on tree trunks, mostly on the north side; and only 12.6% were resting on or under twigs. Following correspondence with Hooper, he added an experiment to find if
bats Bats are mammals of the Order (biology), order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in fli ...
, not birds, could be the main predators. He observed a number of species of bird actually preying on the moths, and found that differential bird predation was a major factor responsible for the decline in ''carbonaria'' frequency compared to ''typica''. He described his results as a complete vindication of the natural selection theory of peppered moth evolution, and said "If the rise and fall of the peppered moth is one of the most visually impacting and easily understood examples of Darwinian evolution in action, it should be taught. It provides after all the proof of evolution." Majerus died before he could complete the writing up of his experiments, so the work was carried on by Cook, Grant, Saccheri and
James Mallet James Mallet (born 15 March 1955 in London) is an evolutionary zoologist specialising in entomology. He was educated at Winchester College. He became professor of biological diversity at the Department of Biology, University College London. He wa ...
, and published on 8 February 2012 as "Selective bird predation on the peppered moth: the last experiment of Michael Majerus." The experiment became the largest ever in the study of industrial melanism, involving 4,864 individuals in a six-year investigation, and it confirmed that melanism in moths is a genuine example of natural selection involving camouflage and predation. Their concluding remark runs: "These data provide the most direct evidence yet to implicate camouflage and bird predation as the overriding explanation for the rise and fall of melanism in moths." Coyne said he was "delighted to agree with this conclusion f Majerus's experiment which answers my previous criticisms about the ''Biston'' story."


See also

* Polymorphism * Scottish red deer


Notes


References


Further reading

*


External links

* Bruce Grant has written several papers on melanism in the peppered moth which are listed o
his home page
* Online lecture
"The rise and fall of the melanic Peppered Moth"
presented by Laurence Cook. *
The Peppered Moth: Decline of a Darwinian Disciple
This is the transcript of Michael Majerus' lecture delivered to the
British Humanist Association Humanists UK, known from 1967 until May 2017 as the British Humanist Association (BHA), is a charitable organisation which promotes secular humanism and aims to represent "people who seek to live good lives without religious or superstitious be ...
on
Darwin Day Darwin Day is a celebration to commemorate the birthday of Charles Darwin on 12 February 1809. The day is used to highlight Darwin's contributions to science and to promote science in general. Darwin Day is celebrated around the world. His ...
2004.
The Peppered Moth: The Proof of Darwinian Evolution
This is the transcript of Majerus' lecture given at the European Society for Evolutionary Biology meeting on 23 August 2007. The accompanying
PowerPoint Microsoft PowerPoint is a presentation program, created by Robert Gaskins and Dennis Austin at a software company named Forethought, Inc. It was released on April 20, 1987, initially for Macintosh computers only. Microsoft acquired PowerPo ...
presentation i
also available
* * On 19 June 2009
Telegraph.co.uk
publishe

on this evolutionary phenomenon and implored UK readers to visit th
Moths Count website
and record their observations of local moths, in an effort to help increase the available data for researchers. {{pepperedmoth
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. Variation ...
Biology experiments Evolution of insects Selection