The most famous experiments on the peppered moth were carried out by Bernard Kettlewell under the supervision of E.B. Ford. In one of Kettlewell's experiments, moths were released into a large (18 m by 6 m) aviary, where they were fed on by Great Tits ("Parus major"). In 1953, Kettlewell experimented at Cadbury Nature Reserve in Birmingham. He marked, released and recaptured the marked moths. He found, in polluted woodland, more "typica" morphs were taken. This showed that the melanistic phenotype was important to the survival of peppered moths in such a habitat. Kettlewell repeated the experiment in 1955 in an unpolluted woodland in Dorset, and again in polluted woods in Birmingham. He was accompanied by Niko Tinbergen, and they made a film of this. Further studies by others found similar results. Finally, in 1996, work on both sides of the Atlantic found a correlation between changes in melanic frequencies and pollution levels.
A field experiment in biology will always have some artificiality, but that has to be balanced against practicality and costs. The most important aspect is that an experiment gives useful information. The only previous experiments of this type were R.A. Fisher and E.B. Ford's with the Scarlet tiger moth.
In 2000 Majerus developed plans for further experiments. In the main experiment in Cambridge from 20012007 Majerus added an experiment to find if bat predation might have skewed the results – this found that bats preyed equally on both forms of the moth. He observed a number bird species preying on the moths. The overall data led him to conclude that differential bird predation was a major factor responsible for the decline in "carbonaria" frequency compared to "typica" in Cambridge during the study period. He described his results as a complete vindication of the peppered moth story, 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, but the work was carried on by others. The paper said that "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". The new data, coupled with the weight of previous data show that "industrial melanism in the peppered moth is still one of the clearest and most easily understood examples of Darwinian evolution in action".
"Biston betularia" caterpillars also occur in two forms, each adapted to a different situation. They develop body colours which match the brown or green twigs of their host plant. This is done by a mechanism called polyphenism. Polyphenism is a kind of polymorphism where different forms of an animal are caused by the same genome. The animal inherits the capability, but the environment determines which form develops. This contrasts with genetic polymorphism of the adults, where each morph (form) inherits a slightly different genome.
Polyphenism occurs when the animal inherits a developmental switch. The switch is sensitive to some environmental cue or trigger. In this case, researchers discovered that visual experience triggered precise color matching.
Papilionoidea
The superfamily Papilionoidea (from the genus Papilio, meaning "butterfly") has all the butterflies except for the skippers, which are in the superfamily Hesperioidea, and the moth-like Hedyloidea.
The six families of Papilionoidea are:
Ditrysia
The Ditrysia are a natural group or clade of insects in the Lepidopteran order. It contains both butterflies and moths. They are called ditrisians because the female has two distinct sexual openings: one for mating, and the other for laying eggs.
About 98% of described species of Lepidoptera belong to Ditrysia. The group can be divided into basal or "incertae sedis" "micromoths", and the Apoditrysia. The Apoditrysia includes mostly the larger moths and the butterflies.
Lycaenidae
The Lycaenidae are the second-largest family of butterflies, with about 6000 species worldwide. They are also called gossamer-winged butterflies.
The family includes many beautiful species. Some, like the Palos Verdes blue, are critically endangered. The Lycaenids were favourites of the Russian novelist and lepidopterist Vladimir Nabokov.
Allotinus fabius
The Angled Darkie ("Allotinus fabius") is a small butterfly. It is found in India, Myanmar and South East Asia. It belongs to the Lycaenidae family.
Allotinus
Allotinus is a genus of butterflies in the family Lycaenidae.
Nyssa (Doctor Who)
Nyssa is a fictional character in the long-running British science fiction television series "Doctor Who". She is played by Sarah Sutton. Nyssa came from the planet Traken. Nyssa was created by writer Johnny Byrne for the Fourth Doctor serial "The Keeper of Traken", but the production team later decided that she should join the Doctor on his travels. She returned in the next serial "Logopolis", in which the Fourth Doctor regenerated, and remained as a companion of the Fifth Doctor. She was a regular in the programme from 1981 to 1983. Sutton was the youngest female actor to play a companion in the series.
Nyssa is a alien from the planet Traken, the daughter of Tremas (a consul of the Traken Union) and stepdaughter of Kassia. She helps the Doctor and Adric to defeat Master. During her journeys with Tegan and Adric aboard the TARDIS, Nyssa finds herself trapped in a mathematical equation by the Master – whom she hates as he is, of course, now using "that face" (her father's). She also encounters a race of androids and their insane ruler, helps foil the genocidal plans of a wounded Terileptil and incidentally start the Great Fire of London, and discovers her remarkable resemblance to Ann Talbot.
Nyssa's fate after she leaves the TARDIS is not known, although the spin-off novel "Asylum", by Peter Darvill-Evans, reveals that she eventually leaves Terminus and settles down as an academic in a university on an unspecified planet. In "Asylum", Nyssa shares an adventure with the Fourth Doctor from a time before he met her, leaving the Doctor with the knowledge that he will have to be extremely careful dealing with Nyssa when they eventually meet to avoid changing history.
Since then, Sutton has also voiced Nyssa in several audio plays alongside Peter Davison as the Fifth Doctor, produced by Big Finish Productions.
Harry Sullivan (Doctor Who)
Harry Sullivan is a fictional character from the British science-fiction television series "Doctor Who". He was a companion of the Fourth Doctor. Harry Sullivan was played by Ian Marter, the character appears as a regular during the programme's twelfth season in 1974–1975.
Harry is a doctor in the Royal Navy, who is also a medical officer to the United Nations Intelligence Taskforce, the military organisation to which the Doctor works for as a scientific advisor. He is first mentioned (though not seen) in "Planet of the Spiders", when the Brigadier thinks the Third Doctor has gone into a coma. The Brigadier calls "Doctor Sullivan" and asks him to come to the Doctor's laboratory, but tells him not to bother when Sergeant Benton wakes the Doctor by offering him a cup of coffee. In the next serial, "Robot", after the Doctor's third regeneration, Sullivan is called in to help him, and ends up travelling aboard the TARDIS with the Fourth Doctor and Sarah-Jane Smith (played by Elisabeth Sladen) for several adventures.