Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within lineages. Charles Darwin was the first to describe the role of natural selection in speciation in his 1859 book On the Origin of Species. He also identified sexual selection as a likely mechanism, but found it problematic.
A maggot is the larva of a fly ; it is applied in particular to the larvae of Brachycera flies, such as houseflies, cheese flies, and blowflies, rather than larvae of the Nematocera, such as mosquitoes and Crane flies. A 2012 study estimated the population of maggots in North America alone to be in excess of 3×1017.
Sympatric speciation is the evolution of a new species from a surviving ancestral species while both continue to inhabit the same geographic region. In evolutionary biology and biogeography, sympatric and sympatry are terms referring to organisms whose ranges overlap so that they occur together at least in some places. If these organisms are closely related, such a distribution may be the result of sympatric speciation. Etymologically, sympatry is derived from the Greek roots συν ("together") and πατρίς ("homeland"). The term was coined by Edward Bagnall Poulton in 1904, who explains the derivation.
The Tortricidae are a family of moths, commonly known as tortrix moths or leafroller moths, in the order Lepidoptera. This large family has over 11,000 species described, and is the sole member of the superfamily Tortricoidea, although the genus Heliocosma is sometimes placed within this superfamily. Many of these are economically important pests. Olethreutidae is a junior synonym. The typical resting posture is with the wings folded back, producing a rather rounded profile.
The apple maggot, also known as the railroad worm, is a species of fruit fly, and a pest of several types of fruits, mainly apples. This species evolved about 150 years ago through a sympatric shift from the native host hawthorn to the domesticated apple species Malus domestica in the northeastern United States. This fly is believed to have been accidentally spread to the western United States from the endemic eastern United States region through contaminated apples at multiple points throughout the 20th century. The apple maggot uses Batesian mimicry as a method of defense, with coloration resembling that of the forelegs and pedipalps of a jumping spider.
In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sharing a common range exemplifies sympatric speciation. Such speciation may be a product of reproductive isolation – which prevents hybrid offspring from being viable or able to reproduce, thereby reducing gene flow – that results in genetic divergence. Sympatric speciation may, but need not, arise through secondary contact, which refers to speciation or divergence in allopatry followed by range expansions leading to an area of sympatry. Sympatric species or taxa in secondary contact may or may not interbreed.
Disruptive selection, also called diversifying selection, describes changes in population genetics in which extreme values for a trait are favored over intermediate values. In this case, the variance of the trait increases and the population is divided into two distinct groups. In this more individuals acquire peripheral character value at both ends of the distribution curve.
Trichogramma is a genus of minute polyphagous wasps that are endoparasitoids of insect eggs. Trichogramma is one of around 80 genera from the family Trichogrammatidae, with over 200 species worldwide.
The codling moth is a member of the Lepidopteran family Tortricidae. They are major pests to agricultural crops, mainly fruits such as apples and pears. Because the larvae are not able to feed on leaves, they are highly dependent on fruits as a food source and thus have a significant impact on crops. The caterpillars bore into fruit and stop it from growing, which leads to premature ripening. Various means of control, including chemical, biological, and preventive, have been implemented. This moth has a widespread distribution, being found on six continents. Adaptive behavior such as diapause and multiple generations per breeding season have allowed this moth to persist even during years of bad climatic conditions.
Ophrys insectifera, the fly orchid, is a species of orchid and the type species of the genus Ophrys. It is remarkable as an example of sexually-deceptive pollination and floral mimicry as well as of a highly-selective and highly evolved plant-pollinator relationship.
The light brown apple moth is a leafroller moth belonging to the lepidopteran family Tortricidae.
Diachasmimorpha mellea is a species of braconid parasitoid wasp which attacks multiple species of Rhagoletis fruit flies, including R. pomonella, the apple maggot fly. This wasp has been found throughout much of the United States and in Central Mexico. It is morphologically similar to and has overlapping range with another apple maggot parasitoid, Diachasma alloeum.
Hermetia illucens, the black soldier fly, is a common and widespread fly of the family Stratiomyidae.
Cydia pomonella granulovirus (CpGV) is a granulovirus belonging to the family Baculoviridae. It has a double-stranded DNA genome that is 123,500 base pairs in length with 143 ORFs. The virus forms small bodies called granules containing a single virion. CpGV is a virus of invertebrates – specifically Cydia pomonella, commonly known as the Codling moth. CpGV is highly pathogenic, it is known as a fast GV – that is, one that will kill its host in the same instar as infection; thus, it is frequently used as a biological pesticide.
Ecological speciation is a form of speciation arising from reproductive isolation that occurs due to an ecological factor that reduces or eliminates gene flow between two populations of a species. Ecological factors can include changes in the environmental conditions in which a species experiences, such as behavioral changes involving predation, predator avoidance, pollinator attraction, and foraging; as well as changes in mate choice due to sexual selection or communication systems. Ecologically-driven reproductive isolation under divergent natural selection leads to the formation of new species. This has been documented in many cases in nature and has been a major focus of research on speciation for the past few decades.
Hoplocampa testudinea, the apple sawfly or European apple sawfly, is a species of sawfly in the family Tenthredinidae. It is native to Europe but has been accidentally introduced into North America where it became invasive. The larvae feed inside the developing fruits of the apple tree.
Lathrolestes ensator is a species of wasp in the family Ichneumonidae. it is a parasitoid of the apple sawfly Hoplocampa testudinea. Both insects are native to Europe, but the sawfly has been accidentally introduced into North America where it has become established. The larvae of the sawfly tunnel into developing apple fruitlets which later fall to the ground, where the larvae continue their development. The wasp parasitises the larvae and has been released in North America as part of a biological control programme for the sawfly.
The scientific study of speciation — how species evolve to become new species — began around the time of Charles Darwin in the middle of the 19th century. Many naturalists at the time recognized the relationship between biogeography and the evolution of species. The 20th century saw the growth of the field of speciation, with major contributors such as Ernst Mayr researching and documenting species' geographic patterns and relationships. The field grew in prominence with the modern evolutionary synthesis in the early part of that century. Since then, research on speciation has expanded immensely.
The Drosophila quinaria species group is a speciose lineage of mushroom-feeding flies studied for their specialist ecology, their parasites, population genetics, and the evolution of immune systems. Quinaria species are part of the Drosophila subgenus.
Drosophila silvestris is a large species of fly in the family Drosophilidae that are primarily black with yellow spots. As a rare species of fruit fly endemic to Hawaii, the fly often experiences reproductive isolation. Despite barriers in nature, D. silvestris is able to breed with D. heteroneura to create hybrid flies in the laboratory.
