Ant
Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...
s (
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
Formicidae in the
order Hymenoptera
Hymenoptera is a large order (biology), order of insects, comprising the sawfly, sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are Par ...
) are the most species-rich of all
social insect
Eusociality (from Greek εὖ ''eu'' "good" and social), the highest level of organization of sociality, is defined by the following characteristics: cooperative brood care (including care of offspring from other individuals), overlapping generat ...
s, with more than 12,000 described
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
and many others awaiting description.
Formicidae is divided into 21
subfamilies
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...
, of which 17 contain
extant
Extant is the opposite of the word extinct. It may refer to:
* Extant hereditary titles
* Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English
* Extant taxon, a taxon which is not extinct, ...
taxa
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...
, while four are exclusively
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
.
Ants have come to occupy virtually all major terrestrial habitats, with the exception of tundra and cold ever-wet forests. They display a wide range of social behaviors, foraging habits and associations with other organisms, which has generated scientific and public interest.
Clades
Beginning in the 1990s, molecular (
DNA sequence
DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine. Th ...
) data have come to play a central role in attempts to reconstruct the ant "
tree of life
The tree of life is a fundamental archetype in many of the world's mythological, religious, and philosophical traditions. It is closely related to the concept of the sacred tree.Giovino, Mariana (2007). ''The Assyrian Sacred Tree: A History ...
".
Molecular phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
analyses based on multiple
nuclear gene
A nuclear gene is a gene whose physical DNA nucleotide sequence is located in the cell nucleus of a eukaryote. The term is used to distinguish nuclear genes from genes found in mitochondria or chloroplasts. The vast majority of genes in eukaryote ...
s have yielded robust results that reinforce some preexisting views but overturn others – and suggest that there has been considerable
morphological convergence
Convergence may refer to:
Arts and media Literature
*''Convergence'' (book series), edited by Ruth Nanda Anshen
* "Convergence" (comics), two separate story lines published by DC Comics:
**A four-part crossover storyline that united the four Wei ...
among some ant lineages. Molecular data provide very strong support for a novel group, the "formicoid
clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...
", not revealed by previous morphological work. This clade comprises 9
of the 16 extant ant subfamilies and about 90% of all described ant species. Formicoids include such widespread and species-rich subfamilies as
Myrmicinae
Myrmicinae is a subfamily of ants, with about 140 extant genera; their distribution is cosmopolitan. The pupae lack cocoons. Some species retain a functional sting. The petioles of Myrmicinae consist of two nodes. The nests are permanent and ...
,
Formicinae
The Formicinae are a subfamily within the Formicidae containing ants of moderate evolutionary development.
Formicines retain some primitive features, such as the presence of cocoons around pupae, the presence of ocelli in workers, and little ...
and
Dolichoderinae
Dolichoderinae is a subfamily of ants, which includes species such as the Argentine ant (''Linepithema humile''), the erratic ant, the odorous house ant, and the cone ant. The subfamily presents a great diversity of species throughout the wor ...
, as well as the
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 a limit ...
s (
Dorylinae
Dorylinae is an ant subfamily, with distributions in both the Old World and New World. Brady ''et al.'' (2014) synonymized the previous dorylomorph subfamilies (Aenictinae, Aenictogitoninae, Cerapachyinae, Ecitoninae, and Leptanilloidinae) unde ...
). Non-formicoids comprise five "poneroid" subfamilies (
Agroecomyrmecinae
Agroecomyrmecinae is a subfamily of ants containing two extant and two fossil genera. The subfamily was originally classified in 1930 by Carpenter as Agroecomyrmecini, a Myrmicinae tribe. Bolton raised the tribe to subfamily status in 2003, sugg ...
,
Amblyoponinae
Amblyoponinae is a subfamily of ants in the poneromorph subfamilies group containing 13 extant genera and one extinct genus. The ants in this subfamily are mostly specialized subterranean predators. Adult workers pierce the integument (non letha ...
,
Paraponerinae
''Paraponera'' is a genus of ants and the only genus in the subfamily Paraponerinae. The name means "near-''Ponera''".
It consists of two species: the extant ''Paraponera clavata'', also known as a bullet ant, found in the Neotropics, and the v ...
,
Ponerinae
Ponerinae is a subfamily of ants in the Poneromorph subfamilies group, with about 1,600 species in 47 extant genera, including ''Dinoponera gigantea'' - one of the world's largest species of ant. Mated workers have replaced the queen as the fun ...
, and
Proceratiinae
Proceratiinae is a subfamily of ants in the poneromorph subfamilies group, with three extant genera, of which most are tropical or subtropical, although overall distribution is worldwide.
Identification
The ants are relatively small to medium i ...
),
Leptanillinae
Leptanillinae is a subfamily of ants. They are further divided into the tribes Anomalomyrmini and Leptanillini.
In all Leptanillini, the larvae feed their hemolymph
Hemolymph, or haemolymph, is a fluid, analogous to the blood in vertebrat ...
, about which little is known, and
Martialinae
''Martialis heureka'' is a species of ant discovered in 2000 from the Amazon rainforest near Manaus, Brazil. It was described as a new species and placed as the sole member of a new subfamily, Martialinae. The generic name means "from Mars" ...
, the most recently discovered subfamily.
Relationships among these remaining seven subfamilies are less well resolved.
A recent study (2011) places Leptanillinae as a
sister group
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree.
Definition
The expression is most easily illustrated by a cladogram:
Taxon A and t ...
to all other ants, with Martialinae, the poneroids and formicoids forming a clade.
Evolution of ants
Ants first arose during the
mid-Cretaceous
The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the ...
, more than 100 million years ago, associated with the rise of flowering plants and an increase in forest ground litter.
The earliest known ants evolved from a lineage within the
aculeate
Aculeata is a subclade of Hymenoptera containing ants, bees, and stinging wasps. The name is a reference to the defining feature of the group, which is the modification of the ovipositor into a stinger. However, many members of the group cannot ...
wasps, and a recent study suggests that they are a sister group of
Apoidea
The superfamily (zoology), superfamily Apoidea is a major group within the Hymenoptera, which includes two traditionally recognized lineages, the "sphecidae, sphecoid" wasps, and the bees. Molecular phylogeny demonstrates that the bees arose from ...
.
During the Cretaceous ants were confined to the northern
Laurasia
Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pan ...
n supercontinent, with only a few widespread primitive species.
By the middle Eocene, around 50 million years ago, ants had diversified and become ecologically dominant as predators and scavengers. Ant species are less than 2% of the total number of insect species but make up one third of the insect biomass.
History of classification
In volume 1 of ''
Systema Naturae
' (originally in Latin written ' with the ligature æ) is one of the major works of the Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the system, now known as binomial nomen ...
'',
Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
(1758) described seventeen species of ants, all of which he placed in the single
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''
Formica
''Formica'' is a genus of ants of the family Formicidae, commonly known as wood ants, mound ants, thatching ants, and field ants. ''Formica'' is the type genus of the Formicidae, and of the subfamily Formicinae. The type species of genus ''For ...
''.
Within a few decades additional genera had been recognized, and this trend continued in the ensuing years, together with the development of a more complex hierarchical classification in which genera were apportioned among subfamilies and
tribes
The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to conflic ...
. The ant species described by Linnaeus are now dispersed in eleven different genera, belonging to four subfamilies.
For much of the twentieth century the number of recognized ant subfamilies varied from seven to ten, with the Aneuretinae, Cerapachyinae, Leptanillinae, Myrmeciinae and Pseudomyrmecinae being variously treated as separate subfamilies or (at different times) subsumed within Dolichoderinae, Ponerinae, Dorylinae, Ponerinae, and Myrmicinae, respectively.
In 2014, Brady et al.
synonymized the army ant subfamilies and their closest relatives under Dorylinae; this clade, the dorylomorph subfamilies, previously also contained Aenictinae, Aenictogitoninae, Cerapachyinae, Ecitoninae and Leptanilloidinae.
The last three decades have seen a proliferation of subfamily names, as a result of three factors: (1) the realization that some subfamilies were assemblages of unrelated taxa; (2) abandonment of
paraphyletic
In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...
taxa, and (3) the discovery of novel fossil taxa.
Seventeen extant subfamilies of ants are currently recognized, along with four extinct subfamilies.
One of the fossil taxa,
Armaniinae
Armaniidae was a name formerly given to a group of extinct ant-like hymenopterans known from a series of Cretaceous fossils found in Asia and Africa. Armaniidae has been suggested by several authors to belong to the family Formicidae as one of t ...
, is often given
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
rank within the
superfamily
SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...
Formicoidea
Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22,00 ...
.
About 13 genera are ''
incertae sedis
' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...
'' (of uncertain placement), and are not assigned to any subfamily.
Subfamilies
Extinct
taxa
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...
are indicated by a
†.
See also
*
List of ant genera
*
Poneromorph subfamilies In ants, the traditional subfamily Ponerinae has been subdivided into several Poneromorph subfamilies, with several former tribes now elevated to subfamily rank. According to this analysis, some ponerine groups may be more closely related to other s ...
Notes
References
*
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{{Formicidae subfamilies
Wikipedia articles incorporating text from open access publications
Ants
Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22,00 ...
Subfamilies
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...
Subfamilies
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...