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In
evolutionary biology Evolutionary biology is the subfield of biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular interacti ...
, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, alters biotic interactions or opens new
environmental niches
environmental niches
. Starting with a single ancestor, this process results in the
speciation 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 ...

speciation
and
phenotypic In genetics Genetics is a branch of biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular inter ...

phenotypic
adaptation of an array of species exhibiting different morphological and physiological traits. The prototypical example of adaptive radiation is finch speciation on the Galapagos ("
Darwin's finches Darwin's finches (also known as the Galápagos finches) are a group of about 18 species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiver ...

Darwin's finches
"), but examples are known from around the world.


Characteristics

Four features can be used to identify an adaptive radiation: #A common ancestry of component species: specifically a ''recent'' ancestry. Note that this is not the same as a
monophyly In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...
in which ''all'' descendants of a common ancestor are included. #A phenotype-environment correlation: a ''significant'' association between environments and the morphological and physiological traits used to exploit those environments. #Trait utility: the performance or fitness advantages of trait values in their corresponding environments. #Rapid speciation: presence of one or more ''bursts'' in the emergence of new species around the time that ecological and phenotypic divergence is underway.


Conditions

Adaptive radiations are thought to be triggered by an ecological opportunity or a new adaptive zone. Sources of ecological opportunity can be the loss of antagonists (
competitors Competition is a rivalry A rivalry is the state of two people or groups engaging in a lasting competitive relationship. Rivalry is the "against each other" spirit between two competing sides. The relationship itself may also be called "a ri ...
or
predators Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation (which ...

predators
), the evolution of a key innovation or dispersal to a new environment. Any one of these ecological opportunities has the potential to result in an increase in population size and relaxed (constraining) selection. As
genetic diversity Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species, it ranges widely from the number of species to differences within species In biology, a species is the basic unit of biological classificati ...
is positively
correlated In statistics, correlation or dependence is any statistical relationship, whether causality, causal or not, between two random variables or bivariate data. In the broadest sense correlation is any statistical association, though it actually re ...
with population size the expanded population will have more genetic diversity compared to the ancestral population. With reduced stabilizing selection
phenotypic In genetics Genetics is a branch of biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular inter ...

phenotypic
diversity can also increase. In addition, intraspecific competition will increase, promoting divergent selection to use a wider range of resources. This ecological release provides the potential for
ecological speciation Ecological speciation is a form of speciation Speciation is the evolution Evolution is change in the Heredity, heritable Phenotypic trait, characteristics of biological populations over successive generations. These characteristics are the ...
and thus adaptive radiation. Occupying a new environment might take place under the following conditions: #A new habitat has opened up: a volcano, for example, can create new ground in the middle of the ocean. This is the case in places like
Hawaii Hawaii ( ; haw, Hawaii or ) is a state State may refer to: Arts, entertainment, and media Literature * ''State Magazine'', a monthly magazine published by the U.S. Department of State * The State (newspaper), ''The State'' (newspape ...

Hawaii
and the Galapagos. For aquatic species, the formation of a large new lake habitat could serve the same purpose; the tectonic movement that formed the
East African Rift The East African Rift (EAR) or East African Rift System (EARS) is an active continental rift zone in East Africa East Africa, Eastern Africa, or East of Africa is the eastern sub-region A subregion is a part of a larger region or continent ...
, ultimately leading to the creation of the
Rift Valley Lakes The Rift Valley lakes are a series of lakes in the East African Rift File:East Africa Rift System GPS and stresses.png, Main rift faults, plates, plate boundaries, GPS plate velocities between adjacent blocks and minimum horizontal stress direc ...

Rift Valley Lakes
, is an example of this. An
extinction event An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity Biodiversity is the biological variety and Genetic variability, variability of life, life on Earth. Biodiversity ...
could effectively achieve this same result, opening up niches that were previously occupied by species that no longer exist. #This new habitat is relatively isolated. When a volcano erupts on the mainland and destroys an adjacent forest, it is likely that the terrestrial plant and animal species that used to live in the destroyed region will recolonize without evolving greatly. However, if a newly formed habitat is isolated, the species that colonize it will likely be somewhat random and uncommon arrivals. #The new habitat has a wide availability of niche space. The rare colonist can only adaptively radiate into as many forms as there are niches. ;Relationship between mass-extinctions and mass adaptive radiations A 2020 study found there to be no direct causal relationship between the proportionally most comparable mass radiations and
extinctions Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the endling, last individual of the species, although the Functional extin ...
in terms of "co-occurrence of species", substantially challenging the hypothesis of "creative mass extinctions".


Examples


Darwin's finches

Darwin's finches are an often-used textbook example of adaptive radiation. Today represented by approximately 15 species, Darwin's finches are Galapagos endemics famously adapted for a specialized feeding behavior (although one species, the Cocos finch ('' Pinaroloxias inornata''), is not found in the Galapagos but on the south of
Costa Rica Costa Rica (, ; ; literally "Rich Coast"), officially the Republic of Costa Rica ( es, República de Costa Rica), is a country in Central America Central America ( es, América Central, , ''Centroamérica'' ) is a region of the Amer ...

Costa Rica
). Darwin's finches are not actually
finch The true finches are small to medium-sized passerine A passerine () is any bird Birds are a group of warm-blooded vertebrate Vertebrates () comprise all species of animal Animals (also called Metazoa) are multicellular ...

finch
es in the true sense, but are members of the tanager family
Thraupidae The tanagers (singular ) comprise the bird family In human society A society is a Social group, group of individuals involved in persistent Social relation, social interaction, or a large social group sharing the same spatial or ...
, and are derived from a single ancestor that arrived in the Galapagos from mainland South America perhaps just 3 million years ago. Excluding the Cocos finch, each species of Darwin's finch is generally widely distributed in the Galapagos and fills the same niche on each island. For the ground finches, this niche is a diet of seeds, and they have thick bills to facilitate the consumption of these hard materials. The ground finches are further specialized to eat seeds of a particular size: the large ground finch ('' Geospiza magnirostris'') is the largest species of Darwin's finch and has the thickest beak for breaking open the toughest seeds, the small ground finch ('' Geospiza fuliginosa'') has a smaller beak for eating smaller seeds, and the medium ground finch (''
Geospiza fortis The medium ground finch (''Geospiza fortis'') is a species of bird Birds are a group of warm-blooded vertebrates constituting the class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a tax ...
'') has a beak of intermediate size for optimal consumption of intermediately sized seeds (relative to ''G. magnirostris'' and ''G. fuliginosa''). There is some overlap: for example, the most robust medium ground finches could have beaks larger than those of the smallest large ground finches. Because of this overlap, it can be difficult to tell the species apart by eye, though their songs differ. These three species often occur sympatrically, and during the rainy season in the Galapagos when food is plentiful, they specialize little and eat the same, easily accessible foods. It was not well-understood why their beaks were so adapted until
Peter and Rosemary Grant Peter Raymond Grant, (born October 26, 1936) and Barbara Rosemary Grant (born October 8, 1936) are a British married couple who are Evolutionary biology, evolutionary biologists at Princeton University. Each currently holds the position of em ...
studied their feeding behavior in the long dry season, and discovered that when food is scarce, the ground finches use their specialized beaks to eat the seeds that they are best suited to eat and thus avoid starvation. The other finches in the Galapagos are similarly uniquely adapted for their particular niche. The cactus finches (''
Geospiza ''Geospiza'' is a genus of bird in the tanager family Thraupidae. All species in the genus are endemic to the Galápagos Islands. Together with related genera, they are collectively known as Darwin's finches. Although in the past, they were classi ...
'' sp.) have somewhat longer beaks than the ground finches that serve the dual purpose of allowing them to feed on
Opuntia ''Opuntia'', commonly called prickly pear, is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circu ...

Opuntia
cactus nectar and pollen while these plants are flowering, but on seeds during the rest of the year. The warbler-finches ('' Certhidea'' sp.) have short, pointed beaks for eating insects. The woodpecker finch ('' Camarhynchus pallidus'') has a slender beak which it uses to pick at wood in search of insects; it also uses small sticks to reach insect prey inside the wood, making it one of the few animals that use tools. The mechanism by which the finches initially diversified is still an area of active research. One proposition is that the finches were able to have a non-adaptive,
allopatric speciation Allopatric speciation (from Ancient Greek ἄλλος, ''allos'', meaning "other", and πατρίς, ''patris'', "fatherland"), also referred to as geographic speciation, vicariant speciation, or its earlier name, the dumbbell model, is a mode of ...
event on separate islands in the archipelago, such that when they reconverged on some islands, they were able to maintain
reproductive isolation The mechanisms of reproductive isolation are a collection of evolution Evolution is change in the heritable Heredity, also called inheritance or biological inheritance, is the passing on of Phenotypic trait, traits from parents to th ...
. Once they occurred in sympatry, niche specialization was favored so that the different species competed less directly for resources. This second, sympatric event was adaptive radiation.


Cichlids of the African Great Lakes

The
haplochromine __NOTOC__ The haplochromine cichlids are a tribe (biology), tribe of cichlids in subfamily Pseudocrenilabrinae called Haplochromini. This group includes the type genus (''Haplochromis'') plus a number of closely related genera such as ''Aulonocar ...
cichlid Cichlids are fish from the family (biology), family Cichlidae in the order Cichliformes. Cichlids were traditionally classed in a suborder, the Labroidei, along with the wrasses (Labridae), in the order Perciformes, but molecular studies have co ...
fishes in the
Great Lakes The Great Lakes also called the Great Lakes of North America or the Laurentian Great Lakes, is a series of large interconnected freshwater lake A lake is an area filled with water, localized in a basin, surrounded by land Land ...

Great Lakes
of the
East African Rift The East African Rift (EAR) or East African Rift System (EARS) is an active continental rift zone in East Africa East Africa, Eastern Africa, or East of Africa is the eastern sub-region A subregion is a part of a larger region or continent ...
(particularly in
Lake Tanganyika Lake Tanganyika is an African Great Lake. It is the second-oldest freshwater lake in the world, the second-largest by volume, and the second-deepest, in all cases after Lake Baikal Lake Baikal (; russian: Oзеро Байкал, Ozero Ba ...

Lake Tanganyika
,
Lake Malawi Lake Malawi, also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique, is an African Great Lakes, African Great Lake and the southernmost lake in the East African Rift system, located between Malawi, Mozambique and Tanzania. It is th ...

Lake Malawi
, and
Lake Victoria Lake Victoria ( luo, Nam Lolwe; lg, 'Nnalubaale; rw, Nyanza; also ''Ukerewe'') is one of the African Great Lakes. Though having multiple local language names, the lake was renamed after Queen Victoria by the explorer John Hanning Speke, the ...

Lake Victoria
) form the most speciose modern example of adaptive radiation. These lakes are believed to be home to about 2,000 different species of cichlid, spanning a wide range of ecological roles and morphological characteristics. Cichlids in these lakes fill nearly all of the roles typically filled by many fish families, including those of predators, scavengers, and herbivores, with varying dentitions and head shapes to match their dietary habits. In each case, the radiation events are only a few million years old, making the high level of speciation particularly remarkable. Several factors could be responsible for this diversity: the availability of a multitude of niches probably favored specialization, as few other fish taxa are present in the lakes (meaning that sympatric speciation was the most probable mechanism for initial specialization). Also, continual changes in the water level of the lakes during the Pleistocene (which often turned the largest lakes into several smaller ones) could have created the conditions for secondary allopatric speciation.


Tanganyika cichlids

Lake Tanganyika Lake Tanganyika is an African Great Lake. It is the second-oldest freshwater lake in the world, the second-largest by volume, and the second-deepest, in all cases after Lake Baikal Lake Baikal (; russian: Oзеро Байкал, Ozero Ba ...

Lake Tanganyika
is the site from which nearly all the cichlid lineages of East Africa (including both riverine and lake species) originated. Thus, the species in the lake constitute a single adaptive radiation event but do not form a single
monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...
clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyly, monophyletic – that is, composed of a common ancestor and all its lineage (evolution), lineal descendants - on a phylogenetic tree. R ...

clade
. Lake Tanganyika is also the least speciose of the three largest African Great Lakes, with only around 200 species of cichlid; however, these cichlids are more morphologically divergent and ecologically distinct than their counterparts in lakes Malawi and Victoria, an artifact of Lake Tanganyika's older cichlid fauna. Lake Tanganyika itself is believed to have formed 9–12 million years ago, putting a recent cap on the age of the lake's cichlid fauna. Many of Tanganyika's cichlids live very specialized lifestyles. The giant or emperor cichlid ('' Boulengerochromis microlepis'') is a piscivore often ranked the largest of all cichlids (though it competes for this title with South America's '''', the speckled peacock bass). It is thought that giant cichlids spawn only a single time, breeding in their third year and defending their young until they reach a large size, before dying of starvation some time thereafter. The three species of '' Altolamprologus'' are also piscivores, but with laterally compressed bodies and thick scales enabling them to chase prey into thin cracks in rocks without damaging their skin. '' Plecodus straeleni'' has evolved large, strangely curved teeth that are designed to scrape scales off of the sides of other fish, scales being its main source of food. '' Gnathochromis permaxillaris'' possesses a large mouth with a protruding upper lip, and feeds by opening this mouth downward onto the sandy lake bottom, sucking in small invertebrates. A number of Tanganyika's cichlids are shell-brooders, meaning that mating pairs lay and fertilize their eggs inside of empty shells on the lake bottom. '''' is a unique egg-brooding species, with 15 cm-long males amassing collections of shells and guarding them in the hopes of attracting females (about 6 cm in length) to lay eggs in these shells. These dominant males must defend their territories from three types of rival: (1) other dominant males looking to steal shells; (2) younger, "sneaker" males looking to fertilize eggs in a dominant male's territory; and (3) tiny, 2–4 cm "parasitic dwarf" males that also attempt to rush in and fertilize eggs in the dominant male's territory. These parasitic dwarf males never grow to the size of dominant males, and the male offspring of dominant and parasitic dwarf males grow with 100% fidelity into the form of their fathers. A number of other highly specialized Tanganyika cichlids exist aside from these examples, including those adapted for life in open lake water up to 200m deep.


Malawi cichlids

The cichlids of Lake Malawi constitute a "species flock" of up to 1000 endemic species. Only seven cichlid species in Lake Malawi are not a part of the species flock: the Eastern happy (''''), the sungwa (''''), and five tilapia species (genera ''
Oreochromis ''Oreochromis'' is a large genus of Oreochromini, oreochromine cichlids, fishes Endemism, endemic to Africa and the Middle East. A few species from this genus have been Introduced species, introduced far outside their native range and are importa ...
'' and ''
Coptodon ''Coptodon'' is a genus of cichlids native to fresh, brackish and coastal marine waters in Africa with ''C. zillii'' also found in the Middle East. It is the only genus in the Tribe (biology), tribe Coptodonini. Formerly included in ''Tilapia (gen ...
''). All of the other cichlid species in the lake are descendants of a single original colonist species, which itself was descended from Tanganyikan ancestors. The common ancestor of Malawi's species flock is believed to have reached the lake 3.4 million years ago at the earliest, making Malawi cichlids' diversification into their present numbers particularly rapid. Malawi's cichlids span a similarly range of feeding behaviors to those of Tanganyika, but also show signs of a much more recent origin. For example, all members of the Malawi species flock are mouth-brooders, meaning the female keeps her eggs in her mouth until they hatch; in almost all species, the eggs are also fertilized in the female's mouth, and in a few species, the females continue to guard their fry in their mouth after they hatch. Males of most species display predominantly blue coloration when mating. However, a number of particularly divergent species are known from Malawi, including the piscivorous '''', which lies on its side in the substrate until small cichlids, perhaps drawn to its broken white patterning, come to inspect the predator - at which point they are swiftly eaten.


Victoria cichlids

Lake Victoria's cichlids are also a species flock, once composed of some 500 or more species. The deliberate introduction of the Nile Perch (''
Lates niloticus The Nile perch (''Lates niloticus''), also known as the African snook, Goliath perch, African barramundi , Goliath barramundi, Giant lates or the Victoria perch, is a species of freshwater fish in family (biology), family Latidae of order (biol ...

Lates niloticus
'') in the 1950s proved disastrous for Victoria cichlids, and the collective biomass of the Victoria cichlid species flock has decreased substantially and an unknown number of species have become extinct. However, the original range of morphological and behavioral diversity seen in the lake's cichlid fauna is still mostly present today, if endangered. These again include cichlids specialized for niches across the trophic spectrum, as in Tanganyika and Malawi, but again, there are standouts. Victoria is famously home to many piscivorous cichlid species, some of which feed by sucking the contents out of mouthbrooding females' mouths. Victoria's cichlids constitute a far younger radiation than even that of Lake Malawi, with estimates of the age of the flock ranging from 200,000 years to as little as 14,000.


Adaptive radiation in Hawaii

Hawaii Hawaii ( ; haw, Hawaii or ) is a state State may refer to: Arts, entertainment, and media Literature * ''State Magazine'', a monthly magazine published by the U.S. Department of State * The State (newspaper), ''The State'' (newspape ...

Hawaii
has served as the site of a number of adaptive radiation events, owing to its isolation, recent origin, and large land area. The three most famous examples of these radiations are presented below, though insects like the Hawaiian flies and ''
Hyposmocoma ''Hyposmocoma'' is a genus of moths with more 350 species endemic to the Hawaiian Islands. The genus was first described by Arthur Gardiner Butler in 1881. Most species of ''Hyposmocoma'' have plant-based diets, but four species, such as ''Hyposmoc ...
'' moths have also undergone adaptive radiation.


Hawaiian honeycreepers

The
Hawaiian honeycreeper Hawaiian honeycreepers are a group of small, passerine A passerine () is any bird Birds are a group of warm-blooded vertebrate Vertebrates () comprise all species of animal Animals (also called Metazoa) are multicellul ...
s form a large, highly morphologically diverse species group of birds that began radiating in the early days of the Hawaiian archipelago. While today only 17 species are known to persist in Hawaii (3 more may or may not be extinct), there were more than 50 species prior to Polynesian colonization of the archipelago (between 18 and 21 species have gone extinct since the discovery of the islands by westerners). The Hawaiian honeycreepers are known for their beaks, which are specialized to satisfy a wide range of dietary needs: for example, the beak of the ʻakiapōlāʻau ('' Hemignathus wilsoni'') is characterized by a short, sharp lower mandible for scraping bark off of trees, and the much longer, curved upper mandible is used to probe the wood underneath for insects. Meanwhile, the ʻiʻiwi ('' Drepanis coccinea'') has a very long curved beak for reaching nectar deep in ''Lobelia'' flowers. An entire clade of Hawaiian honeycreepers, the tribe Psittirostrini, is composed of thick-billed, mostly seed-eating birds, like the Laysan finch (''Laysan finch, Telespiza cantans''). In at least some cases, similar morphologies and behaviors appear to have evolved convergently among the Hawaiian honeycreepers; for example, the short, pointed beaks of ''Loxops'' and ''ʻAkikiki, Oreomystis'' evolved separately despite once forming the justification for lumping the two genera together. The Hawaiian honeycreepers are believed to have descended from a single common ancestor some 15 to 20 million years ago, though estimates range as low as 3.5 million years.


Hawaiian silverswords

Adaptive radiation is not a strictly vertebrate phenomenon, and examples are also known from among plants. The most famous example of adaptive radiation in plants is quite possibly the Hawaiian Argyroxiphium, silverswords, named for alpine desert-dwelling ''Argyroxiphium'' species with long, silvery leaves that live for up to 20 years before growing a single flowering stalk and then dying. The Hawaiian silversword alliance consists of twenty-eight species of Hawaiian plants which, aside from the namesake silverswords, includes trees, shrubs, vines, cushion plants, and more. The silversword alliance is believed to have originated in Hawaii no more than 6 million years ago, making this one of Hawaii's youngest adaptive radiation events. This means that the silverswords evolved on Hawaii's modern high islands, and descended from a single common ancestor that arrived on Kauai from western North America. The closest modern relatives of the silverswords today are California tarweeds of the family Asteraceae.


Hawaiian lobelioids

Hawaii is also the site of a separate major floral adaptive radiation event: the Hawaiian lobelioids. The Hawaiian lobelioids are significantly more speciose than the silverswords, perhaps because they have been present in Hawaii for so much longer: they descended from a single common ancestor who arrived in the archipelago up to 15 million years ago. Today the Hawaiian lobelioids form a clade of over 125 species, including succulents, trees, shrubs, epiphytes, etc. Many species have been lost to extinction and many of the surviving species endangered.


Caribbean anoles

Anole lizards are distributed broadly in the New World, from the Southeastern US to South America. With over 400 species currently recognized, often placed in a single genus (''Anolis''), they constitute one of the largest radiation events among all lizards. Anole radiation on the mainland has largely been a process of speciation, and is not adaptive to any great degree, but anoles on each of the Greater Antilles (Cuba, Hispaniola, Puerto Rico, and Jamaica) have adaptively radiated in separate, convergent ways. On each of these islands, anoles have evolved with such a consistent set of morphological adaptations that each species can be assigned to one of six "Anolis ecomorphs, ecomorphs": trunk–ground, trunk–crown, grass–bush, crown–giant, twig, and trunk. Take, for example, crown–giants from each of these islands: the Cuban ''Anolis luteogularis'', Hispaniola's ''Anolis ricordii'', Puerto Rico's ''Anolis cuvieri'', and Jamaica's ''Jamaican giant anole, Anolis garmani'' (Cuba and Hispaniola are both home to more than one species of crown–giant). These anoles are all large, canopy-dwelling species with large heads and large lamellae (scales on the undersides of the fingers and toes that are important for traction in climbing), and yet none of these species are particularly closely related and appear to have evolved these similar traits independently. The same can be said of the other five ecomorphs across the Caribbean's four largest islands. Much like in the case of the cichlids of the three largest African Great Lakes, each of these islands is home to its own convergent ''Anolis'' adaptive radiation event.


Other examples

Presented above are the most well-documented examples of modern adaptive radiation, but other examples are known. Populations of Three-spined stickleback, three-spined sticklebacks have repeatedly diverged and evolved into distinct ecotypes. On Madagascar, birds of the family Vanga, Vangidae are marked by very distinct beak shapes to suit their ecological roles. Madagascan Mantellidae, mantellid frogs have radiated into forms that mirror other tropical frog faunas, with the brightly colored mantellas (''Mantella'') having evolved convergently with the Neotropical poison dart frogs of Poison dart frog, Dendrobatidae, while the arboreal ''Boophis'' species are the Madagascan equivalent of Hylidae, tree frogs and glass frogs. The Pseudoxyrhophiinae, pseudoxyrhophiine snakes of Madagascar have evolved into fossorial, arboreal, terrestrial, and semi-aquatic forms that converge with the colubroid faunas in the rest of the world. These Madagascan examples are significantly older than most of the other examples presented here: Madagascar's fauna has been evolving in isolation since the island split from India some 88 million years ago, and the Mantellidae originated around 50 mya. Older examples are known: the Cretaceous-Paleogene extinction event, K-Pg extinction event, which caused the disappearance of the dinosaurs and most other reptilian megafauna 65 million years ago, is seen as having triggered a global adaptive radiation event that created the mammal diversity that exists today.


See also

* Cambrian explosion—the most notable evolutionary radiation event * Evolutionary radiation—a more general term to describe any radiation * List of adaptive radiated Hawaiian honeycreepers by form * List of adaptive radiated marsupials by form * Nonadaptive radiation


References


Further reading

* Wilson, E. et al. ''Life on Earth,'' by Wilson, E.; Eisner, T.; Briggs, W.; Dickerson, R.; Metzenberg, R.; O'Brien, R.; Susman, M.; Boggs, W. (Sinauer Associates, Inc., Publishers, Stamford, Connecticut), c 1974. Chapters: ''The Multiplication of Species; Biogeography,'' pp 824–877. 40 Graphs, w species pictures, also Tables, Photos, etc. Includes Galápagos Islands,
Hawaii Hawaii ( ; haw, Hawaii or ) is a state State may refer to: Arts, entertainment, and media Literature * ''State Magazine'', a monthly magazine published by the U.S. Department of State * The State (newspaper), ''The State'' (newspape ...

Hawaii
, and Australia (continent), Australia subcontinent, (plus St. Helena Island, etc.). * Richard Leakey, Leakey, Richard. ''The Origin of Humankind''—on adaptive radiation in biology and human evolution, pp. 28–32, 1994, Orion Publishing. * Grant, P.R. 1999. The ecology and evolution of Darwin's Finches. Princeton University Press, Princeton, NJ. * Ernst Mayr, Mayr, Ernst. 2001. What evolution is. Basic Books, New York, NY. * * * Gavrilets, S. and A. Vose. 2009. ''Dynamic patterns of adaptive radiation: evolution of mating preferences''. In Butlin, R.K., J. Bridle, and D. Schluter (eds) Speciation and Patterns of Diversity, Cambridge University Press, page. 102–126. * * * * * * Pinto, Gabriel, Luke Mahler, Luke J. Harmon, and Jonathan B. Losos. "Testing the Island Effect in Adaptive Radiation: Rates and Patterns of Morphological Diversification in Caribbean and Mainland Anolis Lizards." NCBI (2008): n. pag. Web. 28 Oct. 2014. * * * Schluter, Dolph. The ecology of adaptive radiation. Oxford University Press, 2000. * {{DEFAULTSORT:Adaptive Radiation Speciation Evolutionary biology terminology