Common postman | |
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H.melpomene martinae, Colombia | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Lepidoptera |
Family: | Nymphalidae |
Genus: | Heliconius |
Species: | H. melpomene |
Binomial name | |
Heliconius melpomene | |
Subspecies | |
Many, see genetics | |
Synonyms | |
Papilio melpomene ( Linnaeus, 1758) |
Heliconius melpomene, the postman butterfly, common postman or simply postman, is a brightly colored, geographically variable butterfly species found throughout Central and South America. It was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae. Its coloration coevolved with another member of the genus, H. erato as a warning to predators of its inedibility; this is an example of Müllerian mimicry. [1] H. melpomene was one of the first butterfly species observed to forage for pollen, a behavior that is common in other insect groups but rare in butterflies. [2] Because of the recent rapid evolutionary radiation of the genus Heliconius and overlapping of its habitat with other related species, H. melpomene has been the subject of extensive study on speciation and hybridization. These hybrids tend to have low fitness as they look different from the original species and no longer exhibit Müllerian mimicry.
Heliconius melpomene possesses ultraviolet vision which enhances its ability to distinguish subtle differences between markings on the wings of other butterflies. [3] This allows the butterfly to avoid mating with other species that share the same geographic range.
The postman butterfly is predominately black with either red or yellow bands across the forewings. The postman butterfly has large long wings (35–39 mm). It is poisonous, and the red patterns on its wings are an example of aposematism. They look similar to H. erato . Two features found on the underside of the hind wings help to distinguish H. erato from H. melpomene—H. erato usually has four red dots where the wing attaches to the thorax while H. melpomene usually has three. In Mexico, Central America and the west coast of Colombia and Ecuador, the yellowish-white stripe on the underside reaches the margin of the hindwing in H. erato but ends before reaching the margin in H. melpomene. [4] [5]
There are many geographical races/subspecies/morphs of this butterfly throughout Central and South America. [6] The geographical variation in patterns has been studied using linkage mapping and it has been found that the patterns are associated with a small number of genetic loci called genomic "hotspots". [7] [8] Hotspot loci for color patterning have been found homologous between co-mimics H. erato and H. melpomene, strengthening evidence for parallel evolution between the two species, across morph patterns. [9] [10]
Heliconius melpomene is found from Central America to South America, especially on the slopes of the Andes mountains. It most commonly inhabits open terrain and forest edges, although it can also be found near the edges of rivers and streams. [4] [5] It shares its range with other Heliconius species, and H. melpomene is usually less abundant than other species. [5]
A recent study, using amplified fragment length polymorphism (AFLP) and mitochondrial DNA datasets, places the origin of H. melpomene to 2.1 million years ago. [11] H. melpomene shows clustering of AFLPs by geography suggesting that the species originated in eastern South America. [11]
Caterpillars of Heliconius exhibit a behavior known as monophagy, [12] meaning they feed on only one kind of plant, specifically the genus Passiflora . In H. melpomene, the host plants are limited to Passiflora oerstedii and Passiflora menispermifolia . Species of the genus Passiflora have evolved many chemical defenses, but Heliconius caterpillars have developed adaptations that allow them to continue to feed on the plants and actually incorporate the toxic compounds into their systems and make them unpalatable to predators. These interactions make Heliconius and Passiflora a model system for studies of coevolution. [13]
Unlike most other butterflies, several Heliconius species have been observed eating pollen as well as nectar. [2] The exact mechanism by which the butterfly digests the pollen is uncertain; it was originally thought that once the pollen was soaked in nectar after ingestion, it would then be able to be digested by the butterfly. Recently, however, the enzyme protease was discovered in the butterfly's saliva, which implies an adaptation for breaking down pollen. [14] This enzyme was found in higher concentrations in the saliva of female butterflies, likely due to the greater need of nutrition associated with reproduction. [14] These adaptations allow the butterflies to extract important amino acids from the pollen, which, in addition to general nutrition benefits, allows H. melpomene to have brighter colors and be more distasteful to predators than their non-pollen-foraging counterparts. It is thought that this foraging adaptation and subsequent enhancement of coloration contributed to the speciation of Heliconius. [2]
Pollen is a rarely utilized but efficient protein source for Lepidoptera species. While foraging for pollen, adults accumulate pollen on the end of their proboscis and the grains stay there for long periods of time. [15] These pollen grains are transferred to the stamen of another plant the butterfly visits while foraging. While there are many plants in H. melpomene's range that provide suitable nutrients, only a few of these are visited by the butterfly. [13] This makes the butterfly an efficient pollinator for the flowers it visits as there is a low likelihood of a plant receiving the wrong kind of pollen. [15]
By foraging for pollen while developing eggs, female H. melpomene butterflies provide valuable amino acids and proteins to their offspring. This reduces the amount of time that the offspring must spend foraging during the larval stage, and thus decreases the chances of larval predation. [2] While this extra foraging behavior on the part of the female increases her likelihood of being eaten, the warning colors highlighting her distaste protect her from would be predators. [2]
Female H. melpomene butterflies recognize host plants by identifying the corresponding chemical compound using chemoreceptors located on her forelegs. When searching for a plant, the butterfly will drum her legs on the plant in order to detect the chemical compounds the plant releases. Once she has found the correct host plant, she will lay eggs singly on separate young leaves. [16] Finding the correct host plant is crucial as H. melpomene larvae are adapted to only feed on certain Passiflora plants. [12]
The eggs of H. melpomene are yellow and approximately 1.5 x 1 mm. [5] They are mostly laid singly or rarely in small clusters on the young leaves of Passiflora plants. Caterpillars live in groups of two to three individuals and are white with black spots. [5] Pupae are spiny and dark brown in color. [5] The adults have black bodies with bright yellow or orange patterns on the wings. [17] Female H. melpomene produce oocytes continuously throughout their life; this is due to the high nutrient diet the butterfly obtains from eating pollen. [18] Closely related Heliconius species have been reported to have a maximum life span of six months, and it is likely that H. melpomene lives for a similar length of time. [19]
Heliconius melpomene coevolved with its sister species, H. erato , each developing similar bright color patterns. [1] The H. melpomene patterns correspond to at least 20 of the 27 H. erato subspecies. [20] [21] This coloration warns potential predators that the butterflies are distasteful and should be avoided; this is an example of aposematism. Since both species possess this acrid taste, they display what is known as Müllerian mimicry. Despite their easily confused coloration, these two species are able to exist in the same habitat range because they are reproductively isolated due to adaptations in the eyes of the butterflies that allow for better distinction between individuals. [1]
Both males and females release a strong odor detectable even to humans when handled in order to deter predation. Additionally, H. melpomene butterflies render themselves unpalatable to predators such as birds by producing cyanogenic glycosides in both the larval and adult stages. [22] These glycosides are incorporated into the insect's system by feeding on host plants that produce the compounds as a defense against herbivory.
Individuals of the genus Heliconius form large communal roosts which they return to each night after foraging. [23] The reason for this behavior was not well characterized until recently when it was determined that the large aggregations of butterflies provided protection from predators. Butterflies fare better in these groups for two reasons. First, the prey dilution effect lowers the likelihood that one particular individual will be eaten because of the large number of other individuals that are in the area. Second, the congregation of the brightly colored individuals is more likely to deter predators by making the warning coloration more prominent. [23]
Due to its overlapping range with many closely related species, H. melpomene sometimes hybridizes in nature despite adaptations meant to counteract this. [24] Females resulting from the cross of H. melpomene and H. cydno are sterile. While hybrid males are not sterile, they exhibit patterns that are intermediate between the crossed species and thus the males are unlikely to be recognized as mates by either species. Furthermore, the patterns on both sexes will be non-mimetic, meaning they will not be recognized by predators as displays of distaste. Therefore, the hybrids resulting from the cross of H. melpomene with other Heliconius species have low fitness and are not likely to persist. [24]
Hybridisation of Heliconius melpomene with Heliconius pardalinus resulted in the hybrid speciation of Heliconius elevatus . [25] [26]
Subspecies of H. melpomene include: [27]
When searching for mates, males of H. melpomene exhibit patrolling behavior, which involves searching for potential mates while flying around the range that the species inhabits. [24] This requires the ability to distinguish H. melpomene females from those of other species, a key adaptation of the butterfly.
Male H. melpomene possess abdominal claspers that are used to grasp females for forced copulations. [28] During mating, the male passes nutrients in a spermatophore; the female can use this nuptial gift to nourish the fertilizing eggs inside her. In addition to the spermatophore, males also deliver a pheromone to the female that is an antiaphrodisiac to other males. This increases the likelihood of the male's reproductive success by preventing the female from mating with any other males, which ensures that only the original male's sperm will be used to fertilize the female's eggs.. The pheromone is produced only by males and is secreted to identify themselves to other males, so the antiaphrodisiac works by making the female smell like a male. [28] After a period of time the pheromone wears off and the female is able to mate again, which she will do several times throughout her life. [17]
Due to a duplication in a gene for UV light detection, H. melpomene individuals are capable of distinguishing between a wider range of yellow shades than other butterfly species. [3] Additionally, when looking for mates, the butterflies distinguish conspecifics from hybrids and heterospecifics by detecting subtle changes in marking patterns on wings. These adaptations allow the butterflies to avoid genetically costly mates, as hybrid females are sterile and hybrid males in this system are less fit due to disruptive sexual selection. [3]
While both sexes of H. melpomene possess taste receptors on their hindlegs, only the female butterflies have the receptors on the forelegs; this is an example of sexual dimorphism. The taste receptors are used by both sexes in order to find food and mates, but the female also uses the sense to find suitable host plants for her eggs. [16] These taste receptors are highly specialized due to the coevolution with the Passiflora plant.
Butterflies are winged insects from the lepidopteran suborder Rhopalocera, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The group comprises the superfamilies Hedyloidea and Papilionoidea. The oldest butterfly fossils have been dated to the Paleocene, about 56 million years ago, though they likely originated in the Late Cretaceous, about 101 million years ago.
In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. Often, mimicry functions to protect a species from predators, making it an anti-predator adaptation. Mimicry evolves if a receiver perceives the similarity between a mimic and a model and as a result changes its behaviour in a way that provides a selective advantage to the mimic. The resemblances that evolve in mimicry can be visual, acoustic, chemical, tactile, or electric, or combinations of these sensory modalities. Mimicry may be to the advantage of both organisms that share a resemblance, in which case it is a form of mutualism; or mimicry can be to the detriment of one, making it parasitic or competitive. The evolutionary convergence between groups is driven by the selective action of a signal-receiver or dupe. Birds, for example, use sight to identify palatable insects and butterflies, whilst avoiding the noxious ones. Over time, palatable insects may evolve to resemble noxious ones, making them mimics and the noxious ones models. In the case of mutualism, sometimes both groups are referred to as "co-mimics". It is often thought that models must be more abundant than mimics, but this is not so. Mimicry may involve numerous species; many harmless species such as hoverflies are Batesian mimics of strongly defended species such as wasps, while many such well-defended species form Müllerian mimicry rings, all resembling each other. Mimicry between prey species and their predators often involves three or more species.
Frequency-dependent selection is an evolutionary process by which the fitness of a phenotype or genotype depends on the phenotype or genotype composition of a given population.
Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates, who worked on butterflies in the rainforests of Brazil.
The viceroy is a North American butterfly. It was long thought to be a Batesian mimic of the monarch butterfly, but since the viceroy is also distasteful to predators, it is now considered a Müllerian mimic instead.
Heliconius charithonia, the zebra longwing or zebra heliconian, is a species of butterfly belonging to the subfamily Heliconiinae of the family Nymphalidae. It was first described by Carl Linnaeus in his 1767 12th edition of Systema Naturae. The boldly striped black and white wing pattern is aposematic, warning off predators. It is the state butterfly of Florida.
Dryas iulia, commonly called the Julia butterfly, Julia heliconian, the flame, or flambeau, is a species of brush-footed butterfly. The sole representative of its genus Dryas, it is native from Brazil to southern Texas and Florida, and in summer can sometimes be found as far north as eastern Nebraska. Over 15 subspecies have been described.
Müllerian mimicry is a natural phenomenon in which two or more well-defended species, often foul-tasting and sharing common predators, have come to mimic each other's honest warning signals, to their mutual benefit. The benefit to Müllerian mimics is that predators only need one unpleasant encounter with one member of a set of Müllerian mimics, and thereafter avoid all similar coloration, whether or not it belongs to the same species as the initial encounter. It is named after the German naturalist Fritz Müller, who first proposed the concept in 1878, supporting his theory with the first mathematical model of frequency-dependent selection, one of the first such models anywhere in biology.
Introgression, also known as introgressive hybridization, in genetics is the transfer of genetic material from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species. Introgression is a long-term process, even when artificial; it may take many hybrid generations before significant backcrossing occurs. This process is distinct from most forms of gene flow in that it occurs between two populations of different species, rather than two populations of the same species.
Heliconius erato, or the red postman, is one of about 40 neotropical species of butterfly belonging to the genus Heliconius. It is also commonly known as the small postman, the red passion flower butterfly, or the crimson-patched longwing. It was described by Carl Linnaeus in his 1758 10th edition of Systema Naturae.
Heliconius cydno, the cydno longwing, is a nymphalid butterfly that ranges from Mexico to northern South America. It is typically found in the forest understory and deposits its eggs on a variety of plants of the genus Passiflora. It is a member of the Heliconiinae subfamily of Central and South America, and it is the only heliconiine that can be considered oligophagous. H. cydno is also characterized by hybridization and Müllerian mimicry. Wing coloration plays a key role in mate choice and has further implications in regards to sympatric speciation. Macrolide scent gland extracts and wing-clicking behavior further characterize this species.
Heliconius comprises a colorful and widespread genus of brush-footed butterflies commonly known as the longwings or heliconians. This genus is distributed throughout the tropical and subtropical regions of the New World, from South America as far north as the southern United States. The larvae of these butterflies eat passion flower vines (Passifloraceae). Adults exhibit bright wing color patterns which signal their distastefulness to potential predators.
Heliconius ismenius, the Ismenius tiger or tiger heliconian, is a butterfly of the family Nymphalidae found in Central America and northern South America. They are abundant as far south as Ecuador and Venezuela and as far north as southern Mexico, Guatemala and Belize. H. ismenius are more commonly called the tiger-striped long wing butterfly. H. ismenius's nickname is derived from its long wing structure as well as the beautiful burnt orange and black stripes. Pierre André Latreille, a French zoologist, described Heliconius ismenius in 1817. H. ismenius resembles a number of other butterflies, an example of Müllerian mimicry.
Heliconius heurippa is a butterfly of the genus Heliconius that is believed by some scientists to be a separate species from—but a hybrid of—the species Heliconius cydno and Heliconius melpomene, making H. heurippa an example of hybrid speciation.
Many types of polymorphism can be seen in the insect order Lepidoptera. Polymorphism is the appearance of forms or "morphs" differing in color and number of attributes within a single species. In Lepidoptera, polymorphism can be seen not only between individuals in a population but also between the sexes as sexual dimorphism, between geographically separated populations in geographical polymorphism and also between generations flying at different seasons of the year. It also includes the phenomenon of mimicry when mimetic morphs fly alongside non-mimetic morphs in a population of a particular species. Polymorphism occurs both at a specific level with heritable variation in the overall morphological design of individuals as well as in certain specific morphological or physiological traits within a species.
Heliconius numata, the Numata longwing, is a brush-footed butterfly species belonging to the family Nymphalidae, subfamily Heliconiinae.
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.
The evo-devo gene toolkit is the small subset of genes in an organism's genome whose products control the organism's embryonic development. Toolkit genes are central to the synthesis of molecular genetics, palaeontology, evolution and developmental biology in the science of evolutionary developmental biology (evo-devo). Many of them are ancient and highly conserved among animal phyla.
Heliconius eleuchia, the white-edged longwing, is a species of Heliconius butterfly described by William Chapman Hewitson in 1853.
Eukaryote hybrid genomes result from interspecific hybridization, where closely related species mate and produce offspring with admixed genomes. The advent of large-scale genomic sequencing has shown that hybridization is common, and that it may represent an important source of novel variation. Although most interspecific hybrids are sterile or less fit than their parents, some may survive and reproduce, enabling the transfer of adaptive variants across the species boundary, and even result in the formation of novel evolutionary lineages. There are two main variants of hybrid species genomes: allopolyploid, which have one full chromosome set from each parent species, and homoploid, which are a mosaic of the parent species genomes with no increase in chromosome number.