Butterfly evolution is the origin and diversification of butterflies through geologic time and over a large portion of the Earth's surface. The earliest known butterfly fossils are from the mid

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

epoch, between 40-50 million years ago.Hall, J.P.W., Robbins, R.K. and Harvey, D.J. (2004). "Extinction and biogeography in the Caribbean: new evidence from a fossil riodinid butterfly in Dominican amber." ''Proceedings of the Royal Society of London B'', 271: 797–801. Their development is closely linked to the evolution of flowering plants, since both adult butterflies and caterpillars feed on flowering plants. Of the 220,000 species of Lepidoptera, about 45,000 species are butterflies, which probably evolved from moths. Butterflies are found throughout the world, except in Antarctica, and are especially numerous in the tropics; they fall into eight different families.

Phylogeny

The butterflies form the clade

Rhopalocera Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which also includes moths. Adult butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The group comprises ...

, which is composed of three superfamilies:

Hedyloidea Hedylidae, the "American moth-butterflies", is a family of insects in the order Lepidoptera, representing the superfamily Hedyloidea. They have traditionally been viewed as an extant sister group of the butterfly superfamily Papilionoidea. In 198 ...

(the moth butterfly family

Hedylidae Hedylidae, the "American moth-butterflies", is a family of insects in the order Lepidoptera, representing the superfamily Hedyloidea. They have traditionally been viewed as an extant sister group of the butterfly superfamily Papilionoidea. In 19 ...

), the Hesperioidea (the skipper family Hesperiidae), and the

Papilionoidea The superfamily Papilionoidea (from the genus '' Papilio'', meaning "butterfly") contains all the butterflies except for the moth-like Hedyloidea. The members of the Papilionoidea may be distinguished by the following combination of character ...

(the true butterfly families

Papilionidae Swallowtail butterflies are large, colorful butterflies in the family Papilionidae, and include over 550 species. Though the majority are tropical, members of the family inhabit every continent except Antarctica. The family includes the larg ...

Pieridae The Pieridae are a large family of butterflies with about 76 genera containing about 1,100 species, mostly from tropical Africa and tropical Asia with some varieties in the more northern regions of North America and Eurasia.DeVries P. J. in Le ...

Nymphalidae The Nymphalidae are the largest family of butterflies, with more than 6,000 species distributed throughout most of the world. Belonging to the superfamily Papilionoidea, they are usually medium-sized to large butterflies. Most species have a red ...

Lycaenidae Lycaenidae is the second-largest family of butterflies (behind Nymphalidae, brush-footed butterflies), with over 6,000 species worldwide, whose members are also called gossamer-winged butterflies. They constitute about 30% of the known butterf ...

, and

Riodinidae Riodinidae is the family of metalmark butterflies. The common name "metalmarks" refers to the small, metallic-looking spots commonly found on their wings. The 1532 species are placed in 146 genera. Although mostly Neotropical in distribution, t ...

). All of these families are monophyletic. The Hedyloidea is the sister group to the other two superfamilies. Within the Papilionoidea, Papilionidae is the sister group to the other families, and Pieridae is the sister group to (Nymphalidae+(Lycaenidae+Riodinidae)). Phylogenetic hypotheses within the Nymphalidae are still under discussion. Current research is concentrated on subfamilial and tribal relationships, especially in the Nymphalidae.

Lines of evidence

The modern study of butterflies' higher classification began with Ehrlich's phenetic use of hundreds of previously overlooked morphological characters in tabular form, across families and major groups (Ehrlich, 1958). Scoble (1995) and others continued the search for new characters, but with their application to

cladism Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived chara ...

. Larval characters are now commonly integrated with those from adult butterflies. The addition of molecular data has allowed researchers to resolve clades in many lineages. Evidence is gleaned from

paleontology Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

where some 50 butterfly

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 ...

s have been identified, from

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines * Morphology (archaeology), study of the shapes or forms of artifacts * Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies ...

and the study of homologies, from

molecular genetics Molecular genetics is a sub-field of biology that addresses how differences in the structures or expression of DNA molecules manifests as variation among organisms. Molecular genetics often applies an "investigative approach" to determine the ...

and comparative

biochemistry Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology and ...

, from comparative

ethology Ethology is the scientific study of animal behaviour, usually with a focus on behaviour under natural conditions, and viewing behaviour as an evolutionarily adaptive trait. Behaviourism as a term also describes the scientific and objecti ...

, and from present-day geographical distributions and ecology.

Fossils

Butterfly fossils have been well covered by Grimaldi & Engel (2005), who point out their weakness in resolving the sister group of the Rhopalocera: butterflies of 45 Mya are much like their living counterparts. The first fossil was formed around 40-50 million years ago.

Host plants

Some species in the Satyrinae use ferns as larval host plants, and it is not impossible that the butterflies could have originated before their present-day angiosperm plant hosts.

Date of origin

Some researchers theorize that butterflies most likely originated in the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

period when the continents were arrayed differently from their present positions and with climates unlike those of today. That is when the major angiosperm radiation took place. Thus, butterfly evolution must be studied throughout the elaboration and testing of

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

hypotheses and through historical

zoogeography Zoogeography is the branch of the science of biogeography that is concerned with geographic distribution (present and past) of animal species. As a multifaceted field of study, zoogeography incorporates methods of molecular biology, genetics, mor ...

. Researchers who accept a Cretaceous origin for the butterflies generally favor

vicariant Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from ...

zoogeographic hypothesis for how the major lineages of butterflies came to be distributed over the world, whereas those who favor a Tertiary age rely on dispersalist hypotheses (Lamas, 2008).

Drivers of speciation

Mimicry, hybridization, and

co-evolution In biology, coevolution occurs when two or more species reciprocally affect each other's evolution through the process of natural selection. The term sometimes is used for two traits in the same species affecting each other's evolution, as well ...

with host plants have probably contributed to speciation in the butterflies (Lamas, 2008).

References

* Ehrlich, P. R. (1958). The comparative morphology, phylogeny and higher classification of the butterflies (Lepidoptera: Papilionidea). ''Kansas Univ. Sci. Bull., 39'', 305-370. * Grimaldi, D. & Engel, M. S. 2005. ''Evolution of the insects''. Cambridge: Cambridge Univ. Press. * Lamas, G. (2008) Systematics of butterflies (Lepidoptera: Hesperioidea and Papilionoidea) in the world: current state and future perspectives (in Spanish). In: Jorge Llorente-Bousquets and Analía Lanteri (eds.) ''Contribuciones taxonómicas en ordens de insectos hiperdiversos''. Mexico City: UNAM. pp. 57–70. * Scoble, M. J. (1995). ''The Lepidoptera, form, function and diversity''. London: The Natural history Museum & Oxford University Press. {{Evolution * Col, Jeananda. (1999) Enchanted Learning - All About Butterflies http://www.enchantedlearning.com/subjects/butterfly/allabout/ Butterflies Butterflies