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75-463: Great Migrations debuted on November 7, 2010 worldwide. The series airs on the Sundays of the same month, spread across four hour-long chapters, excluding three supplemental hours which run on other dates. The National Geographic Channel estimated that the show's premiere would be accessible in 330 million homes across the globe. The production team traveled 420,000 miles (680,000 km) over two and

150-459: A monophyletic group, based on data from three molecular genes and one mitochondrial gene. Brady concluded that these groups are, therefore, a single lineage that evolved in the mid-Cretaceous period in Gondwana , so these subfamilies are now generally united into a single subfamily Dorylinae , though this is still not universally recognized. However, the unification of these lineages means that

225-435: A balance or equilibrium between morphs. The mechanisms that conserve it are types of balancing selection . Most genes have more than one effect on the phenotype of an organism ( pleiotropism ). Some of these effects may be visible, and others cryptic, so it is often important to look beyond the most obvious effects of a gene to identify other effects. Cases occur where a gene affects an unimportant visible characteristic, yet

300-432: A change in fitness is recorded. In such cases, the gene's subsurface effects may be responsible for the change in fitness. Pleiotropism is posing continual challenges for many clinical dysmorphologists in their attempt to explain birth defects which affect one or more organ system, with only a single underlying causative agent. For many pleiotropic disorders, the connection between the genetic abnormality and its manifestations

375-415: A colony loses its queen, the worker ants will usually fuse with another colony that has a queen, within a few days. Sometimes, the workers will backtrack along the paths of prior emigrations to search for a queen that has been lost or merge with a sister colony. By merging with a related colony, the workers would increase their overall inclusive fitness . The workers that merge into a new colony may cause

450-452: A couple of decades the work of Fisher, Ford, Arthur Cain , Philip Sheppard and Cyril Clarke promoted natural selection as the primary explanation of variation in natural populations, instead of genetic drift. Evidence can be seen in Mayr's famous book Animal Species and Evolution , and Ford's Ecological Genetics . Similar shifts in emphasis can be seen in most of the other participants in

525-505: A founder of niche research, commented "It is very likely from an ecological point of view that all species, or at least all common species, consist of populations adapted to more than one niche". He gave as examples sexual size dimorphism and mimicry. In many cases where the male is short-lived and smaller than the female, he does not compete with her during her late pre-adult and adult life. Size difference may permit both sexes to exploit different niches. In elaborate cases of mimicry , such as

600-399: A half years tracking multiple species ranging from army ants to Mali elephants. Cinematographers went to great lengths to film the species and their migratory habits, although none were hurt in the process. Filming provided rare footage of various animal scenes, including the documentation of an elephant's funeral for the first time outside East Africa . Various technologies were used to film

675-499: A limited area. Another shared feature is that, unlike most ant species, army ants do not construct permanent nests; an army ant colony moves almost incessantly over the time it exists. All species are members of the true ant family, Formicidae , but several groups have independently evolved the same basic behavioural and ecological syndrome. This syndrome is often referred to as "legionary behaviour", and may be an example of convergent evolution . Most New World army ants belong to

750-457: A month, resulting in synchronized brood cycles and colonies composed of millions of individuals all related to a single queen. The term "army ant syndrome" refers to behavioral and reproductive traits such as obligate collective foraging, nomadism and highly specialized queens that allow these organisms to become the most ferocious social hunters. Most ant species will send individual scouts to find food sources and later recruit others from

825-401: A more formal term is morphotype. Form and phase are sometimes used, but are easily confused in zoology with, respectively, "form" in a population of animals, and "phase" as a color or other change in an organism due to environmental conditions (temperature, humidity, etc.). Phenotypic traits and characteristics are also possible descriptions, though that would imply just a limited aspect of

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900-409: A nest like most other ants. Instead, they build a living nest with their bodies, known as a bivouac . Bivouacs tend to be found in tree trunks or in burrows dug by the ants. The members of the bivouac hold onto each other's legs and so build a sort of ball, which may look unstructured to a layman's eyes, but is actually a well-organized structure. The older female workers are located on the exterior; in

975-422: A sexual brood to nest for a period of 41–56 days, as compared to non-reproductive colonies that remain in the nest an average of 17 days before returning to a nomadic phase. This suggests that if workers produced male offspring, they might be hatched out of sync with the queen's sexual brood and not likely to be successfully reared to adulthood. Army ants can get lost from the pheromone track while foraging, making

1050-505: A sexual brood. As soon as they are born, they will fly off in search of a queen to mate with. In some instances where males seek to mate with a queen from an existing colony, the receiving workers will forcibly remove the wings in order to accommodate the large males into the colony for mating. Because of their size, males are sometimes called "sausage flies" or "sausage ants." Colonies of real army ants always have only one queen, while some other ant species can have several queens. The queen

1125-435: A single common ancestor, which lived approximately 100 million years ago at the time of the separation of the continents of Africa and South America , while other army ant lineages (Leptanillinae, plus members of Ponerinae, Amblyoponinae, and Myrmicinae) are still considered to represent independent evolutionary events. Army ant taxonomy remains in flux, and genetic analysis will likely continue to provide more information about

1200-491: A species from each other. Presently, geneticists use the term genetic polymorphism to describe the functionally silent differences in DNA sequence between individuals that make each human genome unique. Genetic polymorphism is actively and steadily maintained in populations by natural selection, in contrast to transient polymorphisms where a form is progressively replaced by another. By definition, genetic polymorphism relates to

1275-423: Is sexual dimorphism , which occurs in many organisms. Other examples are mimetic forms of butterflies (see mimicry ), and human hemoglobin and blood types . According to the theory of evolution, polymorphism results from evolutionary processes, as does any aspect of a species. It is heritable and is modified by natural selection . In polyphenism, an individual's genetic makeup allows for different morphs, and

1350-677: Is a long-standing debate as to how this situation could have arisen, and the question is not yet resolved. Whereas a gene family (several tightly linked genes performing similar or identical functions) arises by duplication of a single original gene, this is usually not the case with supergenes. In a supergene some of the constituent genes have quite distinct functions, so they must have come together under selection. This process might involve suppression of crossing-over, translocation of chromosome fragments and possibly occasional cistron duplication. That crossing-over can be suppressed by selection has been known for many years. Debate has centered round

1425-449: Is called the switch . This switch may be genetic, or it may be environmental. Taking sex determination as the example, in humans the determination is genetic, by the XY sex-determination system . In Hymenoptera ( ants , bees and wasps ), sex determination is by haplo-diploidy: the females are all diploid , the males are haploid . However, in some animals an environmental trigger determines

1500-434: Is dichthadiigyne (a blind ant with large gaster ) but may sometimes possess vestigial eyes. The queens of army ants are unique in that they do not have wings, have an enlarged gaster size and an extended cylindrical abdomen. They are significantly larger than worker army ants and possess 10–12 segments on their antennae. Queens will mate with multiple males and because of their enlarged gaster, can produce 3 to 4 million eggs

1575-472: Is neither apparent nor understood. Epistasis occurs when the expression of one gene is modified by another gene. For example, gene A only shows its effect when allele B1 (at another locus ) is present, but not if it is absent. This is one of the ways in which two or more genes may combine to produce a coordinated change in more than one characteristic (for instance, in mimicry). Unlike the supergene, epistatic genes do not need to be closely linked or even on

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1650-448: Is strongly tied to the adaptation of a species to its environment, which may vary in colour, food supply, and predation and in many other ways including sexual harassment avoidance. Polymorphism is one good way the opportunities get to be used; it has survival value, and the selection of modifier genes may reinforce the polymorphism. In addition, polymorphism seems to be associated with a higher rate of speciation . G. Evelyn Hutchinson ,

1725-482: Is termed 'polymorphism'. However, if the jaguar has only one possible trait for that gene, it would be termed "monomorphic". For example, if there was only one possible skin colour that a jaguar could have, it would be termed monomorphic. The term polyphenism can be used to clarify that the different forms arise from the same genotype . Genetic polymorphism is a term used somewhat differently by geneticists and molecular biologists to describe certain mutations in

1800-889: The ICN . Horticulturists sometimes confuse this usage of "variety" both with cultivar ("variety" in viticultural usage, rice agriculture jargon, and informal gardening lingo) and with the legal concept " plant variety " (protection of a cultivar as a form of intellectual property ). Three mechanisms may cause polymorphism: Endler's survey of natural selection gave an indication of the relative importance of polymorphisms among studies showing natural selection. The results, in summary: Number of species demonstrating natural selection: 141. Number showing quantitative traits: 56. Number showing polymorphic traits: 62. Number showing both Q and P traits: 23. This shows that polymorphisms are found to be at least as common as continuous variation in studies of natural selection, and hence just as likely to be part of

1875-522: The Mesolithic Holocene . Non-human apes have similar blood groups to humans; this strongly suggests that this kind of polymorphism is ancient, at least as far back as the last common ancestor of the apes and man, and possibly even further. The relative proportions of the morphs may vary; the actual values are determined by the effective fitness of the morphs at a particular time and place. The mechanism of heterozygote advantage assures

1950-508: The gastrozooids ; the individuals capable of asexual reproduction only, the gonozooids, blastostyles; and free-living or sexually reproducing individuals, the medusae . Balanced polymorphism refers to the maintenance of different phenotypes in population. Monomorphism means having only one form. Dimorphism means having two forms. Polymorphism crosses several discipline boundaries, including ecology, genetics, evolution theory, taxonomy, cytology, and biochemistry. Different disciplines may give

2025-462: The population of a species. To be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population (one with random mating). Put simply, polymorphism is when there are two or more possibilities of a trait on a gene. For example, there is more than one possible trait in terms of a jaguar's skin colouring; they can be light morph or dark morph. Due to having more than one possible variation for this gene, it

2100-550: The African Dorylus . These undesired prey are simply left behind and consumed by scavengers or by the flies that accompany the ant swarm. Only a few species hunt primarily on the surface of the earth; they seek their prey mainly in leaf litter and in low vegetation. About five species hunt in higher trees, where they can attack birds and their eggs, although they focus on hunting other social insects along with their eggs and larvae. Colonies of army ants are large compared to

2175-722: The African butterfly Papilio dardanus , female morphs mimic a range of distasteful models called Batesian mimicry, often in the same region. The fitness of each type of mimic decreases as it becomes more common, so the polymorphism is maintained by frequency-dependent selection. Thus the efficiency of the mimicry is maintained in a much increased total population. However it can exist within one gender. Female-limited polymorphism and sexual assault avoidance Female-limited polymorphism in Papilio dardanus can be described as an outcome of sexual conflict. Cook et al. (1994) argued that

2250-445: The ants follow each other in a circular motion, potentially causing them to die of exhaustion . The whole colony of army ants can consume up to 500,000 prey animals each day, so can have a significant influence on the population , diversity, and behaviour of their prey. The prey selection differs with the species. Underground species prey primarily on ground-dwelling arthropods and their larvae , earthworms , and occasionally also

2325-659: The best opportunities to see many of these species. Depending on the size of the ant swarm and the amount of prey the ants stir up, birds can number from a few to dozens of individuals. Birds that frequent army-ant swarms include the white-whiskered puffbird , rufous motmot , rufous-vented ground cuckoo , grey-cowled wood rail , plain-brown woodcreeper , northern barred woodcreeper , cocoa woodcreeper , black-striped woodcreeper , fasciated antshrike , black-crowned antshrike , spotted antbird , bicolored antbird , ocellated antbird , chestnut-backed antbird , black-faced antthrush , and gray-headed tanager . Army ants do not build

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2400-521: The body. In the taxonomic nomenclature of zoology , the word "morpha" plus a Latin name for the morph can be added to a binomial or trinomial name. However, this invites confusion with geographically variant ring species or subspecies , especially if polytypic. Morphs have no formal standing in the ICZN . In botanical taxonomy , the concept of morphs is represented with the terms " variety ", " subvariety " and " form ", which are formally regulated by

2475-405: The colonies of other Formicidae. Colonies can have over 15 million workers and can transport 3000 prey (items) per hour during the raid period. When army ants forage, the trails that are formed can be over 20 m (66 ft) wide and over 100 m (330 ft) long. They stay on the path through the use of a concentration gradient of pheromones. The concentration of pheromone is highest in

2550-448: The colony to help; however, army ants dispatch a cooperative, leaderless group of foragers to detect and overwhelm the prey at once. Army ants do not have a permanent nest but instead form many bivouacs as they travel. The constant traveling is due to the need to hunt large amounts of prey to feed its enormous colony population . Their queens are wingless and have abdomens that expand significantly during egg production. This allows for

2625-402: The colony to increase in size by 50%. Workers in army ant species have a unique role in selecting both the queen and the male mate. When the queens emerge, the workers in the colony will form two 'systems' or arms in opposite directions. These queens that are hatched will move down either of the arms and only two queens will succeed, one for each branch. Any remaining new queens will be left in

2700-404: The evolutionary process. Since all polymorphism has a genetic basis, genetic polymorphism has a particular meaning: The definition has three parts: a) sympatry : one interbreeding population; b) discrete forms; and c) not maintained just by mutation. In simple words, the term polymorphism was originally used to describe variations in shape and form that distinguish normal individuals within

2775-433: The field: And in the laboratory: Without proper field-work, the significance of the polymorphism to the species is uncertain and without laboratory breeding the genetic basis is obscure. Even with insects, the work may take many years; examples of Batesian mimicry noted in the nineteenth century are still being researched. Polymorphism was crucial to research in ecological genetics by E. B. Ford and his co-workers from

2850-583: The forest floor, under tree bark, and other such locations, thereby allowing predators to catch them more easily. For example, in the tropical rainforests of Panama, swarms of army ants attract many species of birds to this feast of scrambling insects, spiders, scorpions, worms, and other animals. Some of these birds are named "antbirds" due to this tendency. While focused on feeding on these invertebrates, birds at army-ant swarms typically allow very close approach by people – within 1–2 metres (3.3–6.6 ft) in many cases – often providing

2925-439: The genera Cheliomyrmex , Neivamyrmex , Nomamyrmex , Labidus , and Eciton . The largest genus is Neivamyrmex , which contains more than 120 species; the most predominant species is Eciton burchellii ; its common name "army ant" is considered to be the archetype of the species. Most Old World army ants are divided between the tribes Aenictini and Dorylini . Aenictini contains more than 50 species of army ants in

3000-724: The genes start on the same chromosome. They argue that supergenes arose in situ . This is known as Turner's sieve hypothesis. John Maynard Smith agreed with this view in his authoritative textbook, but the question is still not definitively settled. Selection, whether natural or artificial, changes the frequency of morphs within a population; this occurs when morphs reproduce with different degrees of success. A genetic (or balanced) polymorphism usually persists over many generations, maintained by two or more opposed and powerful selection pressures. Diver (1929) found banding morphs in Cepaea nemoralis could be seen in prefossil shells going back to

3075-413: The genotype, such as single nucleotide polymorphisms that may not always correspond to a phenotype, but always corresponds to a branch in the genetic tree. See below . Polymorphism is common in nature; it is related to biodiversity , genetic variation , and adaptation . Polymorphism usually functions to retain a variety of forms in a population living in a varied environment. The most common example

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3150-410: The greatest reproductive potential among insects, with an egg-laying capacity of several million per month. Army ant queens never have to leave the protection of the colony, where they mate with foreign incoming males which disperse on nuptial flights . The exact mating behaviour of the army ant queen is still unknown, but observations seem to imply that queens may be fertilized by multiple males. Due to

3225-541: The insects that are flushed out by the ants, a behavior known as kleptoparasitism . A wide variety of arthropods including staphylinid beetles, histerid beetles, spiders, silverfish, isopods, and mites also follow colonies. While some guests follow the colony emigrations on foot, many others are phoretically transported, for example by attaching themselves on army ant workers such as the histerid beetle Nymphister kronaueri . The Neotropical army ant Eciton burchellii has an estimated 350 to 500 animal associates,

3300-833: The interior are the younger female workers. At the smallest disturbance, soldiers gather on the top surface of the bivouac, ready to defend the nest with powerful mandibles and (in the case of the Ecitoninae ) stingers. Inside the nest, there are numerous passages that have 'chambers' of food, larvae, eggs, and most importantly, the queen. Many species of army ants are widely considered to be keystone species due to their important ecological role as arthropod predators and due to their large number of vertebrate and invertebrate associates that rely on army ant colonies for nutrition or protection. During their hunt, many surface-raiding army ants are accompanied by various birds, such as antbirds , thrushes , ovenbirds and wrens , which devour

3375-400: The larvae are now fed exclusively to the queen. The abdomen ( gaster ) of the queen swells significantly, and she lays her eggs. At the end of the stationary phase, both the pupae emerge from their cocoons ( eclosion ) and the next generation of eggs hatch so the colony has a new group of workers and larvae. After this, the ants resume the nomadic phase. Army ants will split into groups when

3450-448: The last quarter of the 20th century when ideas such as Kimura 's neutral theory of molecular evolution was given much attention. The significance of the work on ecological genetics is that it has shown how important selection is in the evolution of natural populations, and that selection is a much stronger force than was envisaged even by those population geneticists who believed in its importance, such as Haldane and Fisher . In just

3525-430: The loss of worker reproduction in the presence of a queen. First, if the worker reproduces, it lowers the general performance of the colony because it is not working. Second, workers increase their inclusive fitness by policing other workers because they themselves are more related to the queen's offspring than other worker's offspring. Lastly, the large male larvae become too large to be transported, forcing colonies with

3600-574: The male-like phenotype in some females in P. dardanus population on Pemba Island, Tanzania functions to avoid detection from a mate-searching male. The researchers found that male mate preference is controlled by frequency-dependent selection, which means that the rare morph suffers less from mating attempt than the common morph. The reasons why females try to avoid male sexual harassment are that male mating attempt can reduce female fitness in many ways such as fecundity and longevity. The mechanism which decides which of several morphs an individual displays

3675-416: The mid-1920s to the 1970s (similar work continues today, especially on mimicry ). The results had a considerable effect on the mid-century evolutionary synthesis , and on present evolutionary theory . The work started at a time when natural selection was largely discounted as the leading mechanism for evolution, continued through the middle period when Sewall Wright 's ideas on drift were prominent, to

3750-469: The middle and are abandoned. Two new bivouacs will be formed and break off into different directions. The workers will surround the two to-be queens to ensure they survive. These workers that surround the queens are affected by the CHC ( pheromone ) profile emitted by the new queen. When males hatch from their brood , they will fly off to find a mate. For males to access the queen and mate, they must run through

3825-416: The middle of the trail, splitting the trail into two distinct regions: an area with high concentration and two areas with low concentrations of pheromones. The outbound ants will occupy the outer two lanes and the returning ants will occupy the central lane. The returning worker ants have also been found to emit more pheromones than those leaving the nest, causing the difference in concentration of pheromone in

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3900-510: The most of any one species known to science. It has been speculated that the nocturnal foraging of some army ant species is done to reduce kleptoparasitism by birds, since the bird kleptoparasites of army ants are diurnal. Historically, "army ant" in the broad sense referred to various members of five different ant subfamilies. In two of these cases, the Ponerinae and Myrmicinae , only a few species and genera exhibit legionary behavior; in

3975-421: The only subfamily that is composed solely of legionary species is Leptanillinae, as Dorylinae contains many non-legionary genera. Accordingly, the "army ants" as presently recognized consist of legionary species in these genera: Polymorphism (biology) In biology , polymorphism is the occurrence of two or more clearly different morphs or forms , also referred to as alternative phenotypes , in

4050-551: The other three lineages, Ecitoninae , Dorylinae , and Leptanillinae , all of the constituent species were considered to be legionary. More recently, ant classifications now recognize an additional New World subfamily, Leptanilloidinae , which also consists of obligate legionary species, so is another group now included among the army ants. A 2003 study of thirty species (by Sean Brady of Cornell University ) indicates that army ants of subfamilies Ecitoninae (South America), Dorylinae (Africa) and Aenictinae (Asia) together formed

4125-427: The population of some alternative alleles at the locus or loci involved. Only if competing selection disappears will an allele disappear. However, heterozygote advantage is not the only way a polymorphism can be maintained. Apostatic selection , whereby a predator consumes a common morph whilst overlooking rarer morphs is possible and does occur. This would tend to preserve rarer morphs from extinction. Polymorphism

4200-541: The production of 3–4 million eggs every month and often results in synchronized brood cycles, thus each colony will be formed of millions of individuals that descend from a single queen. These three traits are found in all army ant species and are the defining traits of army ants. Army ants have two phases of activity – a nomadic (wandering) phase and a stationary (statary) phase – that constantly cycle, and can be found throughout all army ant species. The nomadic phase begins around 10 days after

4275-404: The queen lays her eggs. This phase will last approximately 15 days to let the larvae develop. The ants move during the day, capturing insects , spiders , and small vertebrates to feed their brood. At dusk, they will form their nests or bivouac, which they change almost daily. At the end of the nomadic phase, the larvae will spin pupal cases and no longer require food. The colony can then live in

4350-423: The queen's large reproductive potential, a colony of army ants can be descended from a single queen. When the queen ant dies, there is no replacement and army ants cannot rear emergency queens. Most of the time, if the queen dies, the colony will likely die too. Queen loss can occur due to accidents during emigrations, predator attack, old age or illness. However, there are possibilities to avoid colony death. When

4425-439: The question of whether the component genes in a super-gene could have started off on separate chromosomes, with subsequent reorganization, or if it is necessary for them to start on the same chromosome. Originally, it was held that chromosome rearrangement would play an important role. This explanation was accepted by E. B. Ford and incorporated into his accounts of ecological genetics. However, many believe it more likely that

4500-452: The relatedness of the various taxa. The workers of army ants are usually blind or can have compound eyes that are reduced to a single lens. There are species of army ants where the worker caste may show polymorphism based on physical differences and job allocations; however, there are also species that show no polymorphism at all. The worker caste is usually composed of sterile female worker ants. The soldiers of army ants are larger than

4575-467: The rest of the workers and find a new nest. Another possibility is that the workers will reject the old queen and new queens will each head a newly-divided colony. The workers will affiliate with individual queens based on the pheromone cues that are unique to each queen. When new bivouacs are formed, communication between the original colony and the new bivouacs will cease. Being the largest ants on Earth, army ants, such as African Dorylus queens have

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4650-476: The same chromosome . Both pleiotropism and epistasis show that a gene need not relate to a character in the simple manner that was once supposed. Although a polymorphism can be controlled by alleles at a single locus (e.g. human ABO blood groups), the more complex forms are controlled by supergenes consisting of several tightly linked genes on a single chromosome . Batesian mimicry in butterflies and heterostyly in angiosperms are good examples. There

4725-420: The same bivouac site for around 20 days, foraging only on approximately two-thirds of these days. This pattern of diurnal activity does not apply to all army ants: there are also species that forage at night ( nocturnal ) or at both day and night ( cathemeral ). The stationary phase, which lasts about two to three weeks, begins when the larvae pupate. From this point on, the prey that were previously fed to

4800-458: The same concept different names, and different concepts may be given the same name. For example, there are the terms established in ecological genetics by E.B. Ford (1975), and for classical genetics by John Maynard Smith (1998). The shorter term morphism was preferred by the evolutionary biologist Julian Huxley (1955). Various synonymous terms exist for the various polymorphic forms of an organism. The most common are morph and morpha, while

4875-494: The sex: alligators are a famous case in point. In ants the distinction between workers and guards is environmental, by the feeding of the grubs. Polymorphism with an environmental trigger is called polyphenism . The polyphenic system does have a degree of environmental flexibility not present in the genetic polymorphism. However, such environmental triggers are the less common of the two methods. Investigation of polymorphism requires use of both field and laboratory techniques. In

4950-426: The show's photography as being "so magnificent that there will be a boomlet in sales of high-definition televisions". Won Primetime Emmy as Best Documentary Film Army ant The name army ant (or legionary ant or marabunta ) is applied to over 200 ant species in different lineages. Because of their aggressive predatory foraging groups, known as "raids", a huge number of ants forage simultaneously over

5025-437: The show, such as the use of high-tech tags on monarch butterflies and elephant seals. The Cineflex Heligimbal gyrostabilized cameras was widely utilized in the production. It allows rock-solid closeups to be shot from a kilometer up, a height that does not disturb the animals being filmed. The series also uses the ultra-slow motion Phantom HD camera by Vision Research and the "beyond high-def" Red camera . Great Migrations

5100-523: The single genus, Aenictus . However, the Dorylini contain the genus Dorylus , the most aggressive group of driver ants; 70 species are known. Originally, some of the Old World and New World lineages of army ants were thought to have evolved independently, in an example of convergent evolution . In 2003, though, genetic analysis of various species suggests that several of these groups evolved from

5175-409: The size of the colony has reached a size threshold, which happens approximately every three years. Wingless virgin queens will hatch among a male sexual brood that hatches at a later date. When the colony fissions, there are two ways new queens are decided. A possible outcome is a new queen will stay at the original nest with a portion of the workers and the male brood while the old queen will leave with

5250-416: The switch mechanism that determines which morph is shown is environmental. In genetic polymorphism, the genetic makeup determines the morph. The term polymorphism also refers to the occurrence of structurally and functionally more than two different types of individuals, called zooids , within the same organism. It is a characteristic feature of cnidarians . For example, Obelia has feeding individuals,

5325-419: The trails. The pheromones will allow foraging to be much more efficient by allowing the army ants to avoid their own former paths and those of their conspecifics. Scaffolds structure has been observed when workers carried heavy prey food to inclined surface. Walking ants are prevented from falling by other ants. While foraging, army ants cause many invertebrates to flee from their hiding places under leaves of

5400-531: The workers in the colony. Males that are favoured are superficially similar in size and shape to the queen. The males also produce large quantities of pheromones to pacify the worker ants. In a colony , the queen is the primary individual responsible for reproduction in the colony. Analysis of genotypes have confirmed that workers are, on average, more closely related to the offspring of the queen than to that of other workers, and that workers rarely, if ever, reproduce. Three factors have been suggested to rationalize

5475-529: The workers, and they have much larger mandibles than the worker class of ants, with older soldiers possessing larger heads and stronger mandibles than the younger ones. They protect the colony, and help carry the heaviest loads of prey to the colony bivouac. Males are large in size and have a large cylindrical abdomen, highly modified mandibles and uncommon genitalia not seen in other ants. They have 13 segments on their antennae, are alated (have wings) and therefore can resemble wasps . Males are born as part of

5550-528: The young of vertebrates, turtle eggs, or oily seeds. A majority of the species, the "colony robbers", specialize in the offspring of other ants and wasps . Only a few species seem to have the very broad spectrum of prey seen in the raiding species. Even these species do not eat every kind of animal. Although small vertebrates that get caught in the raid will be killed, the jaws of the American Eciton are not suited to this type of prey, in contrast to

5625-462: Was acclaimed, with considerable praise its cinematography and photography. The Washington Post remarked on the show's "compelling grandeur"; reviewer Tom Shales noted how contemporary nature films would inevitably be compared with the BBC classics, Planet Earth and Life . Great Migrations , he felt, superseded both in its narration and score. The Edmonton Journal went to the extent of praising

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