Peripatric speciation#Quantum and budding speciation

{{main|History of speciation}}

Peripatric speciation was originally proposed by Ernst Mayr in 1954, and fully theoretically modeled in 1982.Ernst Mayr. (1982). Processes of speciation in animals. In A. R. I. Liss. (eds) Mechanisms of Speciation, Alan R. Liss Inc., New York. Pp. 1–19. It is related to the founder effect, where small living populations may undergo selection bottlenecks.{{cite journal |author=W. B. Provine |title=Ernst Mayr: Genetics and speciation |url=http://www.genetics.org/cgi/content/full/167/3/1041 |journal=Genetics |volume=167 |issue=3 |pages=1041–6 |date=1 July 2004|doi=10.1093/genetics/167.3.1041 |pmid=15280221 |pmc=1470966 }} The founder effect is based on models that suggest peripatric speciation can occur by the interaction of selection and genetic drift,{{rp|106}} which may play a significant role.{{cite journal |author=Alan R. Templeton |title=The theory of speciation via the founder principle |url=http://www.genetics.org/cgi/reprint/94/4/1011 |journal=Genetics |volume=94 |issue=4 |pages=1011–38 |date=1 April 1980|doi=10.1093/genetics/94.4.1011 |pmid=6777243 |pmc=1214177 }} Mayr first conceived of the idea by his observations of kingfisher populations in New Guinea and its surrounding islands.{{rp|389}} Tanysiptera galatea was largely uniform in morphology on the mainland, but the populations on the surrounding islands differed significantly—referring to this pattern as "peripatric".{{rp|389}} This same pattern was observed by many of Mayr's contemporaries at the time such as by E. B. Ford's studies of Maniola jurtina.{{Citation | title=Animal Species and Evolution | author=Ernst Mayr | date=1963 | pages=1–797 | publisher=Harvard University Press }}{{rp|522}} Around the same time, the botanist Verne Grant developed a model of quantum speciation very similar to Mayr's model in the context of plants.

In what has been called Mayr's genetic revolutions, he postulated that genetic drift played the primary role that resulted in this pattern.{{rp|389}} Seeing that a species cohesion is maintained by conservative forces such as epistasis and the slow pace of the spread of favorable alleles in a large population (based heavily on J. B. S. Haldane's calculations), he reasoned that speciation could only take place in which a population bottleneck occurred.{{rp|389}} A small, isolated, founder population could be established on an island for example. Containing less genetic variation from the main population, shifts in allele frequencies may occur from different selection pressures.{{rp|390}} This to further changes in the network of linked loci, driving a cascade of genetic change, or a "genetic revolution"—a large-scale reorganization of the entire genome of the peripheral population.{{rp|391}} Mayr did recognize that the chances of success were incredibly low and that extinction was likely; though noting that some examples of successful founder populations existed at the time.{{rp|522}}

Shortly after Mayr, William Louis Brown, Jr. proposed an alternative model of peripatric speciation in 1957 called centrifugal speciation. In 1976 and 1980, the Kaneshiro model of peripatric speciation was developed by Kenneth Y. Kaneshiro which focused on sexual selection as a driver for speciation during population bottlenecks.{{Citation |title=Ethological isolation and phylogeny in the Plantibia subgroup of Hawaiian Drosophila |author=Kenneth Y. Kaneshiro |journal=Evolution |year=1976 |volume=30 |issue= 4 |pages=740–745 |doi=10.1111/j.1558-5646.1976.tb00954.x |pmid=28563322 |s2cid=205773169 }}{{Citation |title=Sexual selection, speciation and the direction of evolution |author=Kenneth Y. Kaneshiro |journal=Evolution |year=1980 |volume=34 |issue= 3|pages=437–444 |doi=10.1111/j.1558-5646.1980.tb04833.x| pmid=28568697 |s2cid=28701838 |doi-access=free }}{{Citation |title=Sexual selection and peripatric speciation: the Kaneshiro model revisited |author=Anders Ödeen & Ann-Britt Florin |journal=Journal of Evolutionary Biology |year=2002 |volume=15 |issue= 2|pages=301–306 |doi=10.1046/j.1420-9101.2002.00378.x|s2cid=82095639 |doi-access=free }}

Peripatric speciation models are identical to models of vicariance (allopatric speciation).{{rp|105}} Requiring both geographic separation and time, speciation can result as a predictable byproduct.{{Citation |title=Theory and speciation |author=Michael Turelli, Nicholas H. Barton, & Jerry A. Coyne |journal=Trends in Ecology & Evolution |year=2001 |volume=16 |issue=7 |pages=330–343 |doi=10.1016/s0169-5347(01)02177-2|pmid=11403865 }} Peripatry can be distinguished from allopatric speciation by three key features:{{rp|105}}

• The size of the isolated population
• Strong selection caused by the dispersal and colonization of novel environments,
• The effects of genetic drift on small populations.

The size of a population is important because individuals colonizing a new habitat likely contain only a small sample of the genetic variation of the original population. This promotes divergence due to strong selective pressures, leading to the rapid fixation of an allele within the descendant population. This gives rise to the potential for genetic incompatibilities to evolve. These incompatibilities cause reproductive isolation, giving rise to—sometimes rapid—speciation events.{{rp|105}} Furthermore, two important predictions are invoked, namely that geological or climatic changes cause populations to become locally fragmented (or regionally when considering allopatric speciation), and that an isolated population's reproductive traits evolve enough as to prevent interbreeding upon potential secondary contact.{{Citation |title=Song divergence at the edge of Amazonia: an empirical test of the peripatric speciation model |author=Nathalie Seddon & Joseph A. Tobias |journal=Biological Journal of the Linnean Society |year=2007 |volume=90 |pages=173–188 |doi=10.1111/j.1095-8312.2007.00753.x|doi-access=free }}

The peripatric model results in, what have been called, progenitor-derivative species pairs, whereby the derivative species (the peripherally isolated population)—geographically and genetically isolated from the progenitor species—diverges.{{Citation |title=Progenitor-derivative species pairs and plant speciation |author=Daniel J. Crawford |journal=Taxon |year=2010 |volume=59 |issue=5 |pages=1413–1423 |doi=10.1002/tax.595008 }} A specific phylogenetic signature results from this mode of speciation: the geographically widespread progenitor species becomes paraphyletic (thereby becoming a paraspecies), with respect to the derivative species (the peripheral isolate).{{rp|470}} The concept of a paraspecies is therefore a logical consequence of the evolutionary species concept, by which one species gives rise to a daughter species.{{cite book|author=James S. Albert & Roberto E. Reis |title=Historical Biogeography of Neotropical Freshwater Fishes |url=https://books.google.com/books?id=V8kZeHxkv9oC&pg=PA316 |isbn=978-0-520-26868-5 |year=2011|publisher=University of California Press }} It is thought that the character traits of the peripherally isolated species become apomorphic, while the central population remains plesiomorphic.{{Citation |title=Modes of Peripheral Isolate Formation and Speciation |author=Jennifer K. Frey |journal=Systematic Biology |year=1993 |volume=42 |issue=3 |pages=373–381 |doi=10.1093/sysbio/42.3.373|s2cid=32546573 }}

Modern cladistic methods have developed definitions that have incidentally removed derivative species by defining clades in a way that assumes that when a speciation event occurs, the original species no longer exists, while two new species arise; this is not the case in peripatric speciation. Mayr warned against this, as it causes a species to lose their classification status.{{Citation|title=A local flora and the biological species concept |author=Ernst Mayr |journal=American Journal of Botany |year=1992 |volume=79 |issue=2 |pages=222–238 |doi=10.2307/2445111 |jstor=2445111 }} Loren H. Rieseberg and Luc Brouillet recognized the same dilemma in plant classification.{{Citation|title=Are many plant species paraphyletic? |author=Loren H. Rieseberg and Luc Brouillet |journal=Taxon |year=1994 |volume=43 |issue=1 |pages=21–32 |doi=10.2307/1223457 |jstor=1223457 }}

The botanist Verne Grant proposed the term quantum speciation that combined the ideas of J. T. Gulick (his observation of the variation of species in semi-isolation), Sewall Wright (his models of genetic drift), Mayr (both his peripatric and genetic revolution models), and George Gaylord Simpson (his development of the idea of quantum evolution).{{Citation|title=Plant Speciation |author=Verne Grant |date=1971 |publisher=Columbia University Press |location=New York |isbn=978-0231083263 |pages=432 }}{{rp|114}} Quantum speciation is a rapid process with large genotypic or phenotypic effects, whereby a new, cross-fertilizing plant species buds off from a larger population as a semi-isolated peripheral population.{{Citation|title=Speciational trends and the role of species in macroevolution |author=Douglas J. Futuyma |journal=The American Naturalist |year=1989 |volume=134 |issue=2 |pages=318–321 |doi=10.1086/284983 |bibcode=1989ANat..134..318F |s2cid=84541831 }}{{rp|114}} Inbreeding and genetic drift take place due to the reduced population size, driving changes to the genome that would most likely result in extinction (due to low adaptive value).{{rp|115}} In rare instances, chromosomal traits with adaptive value may arise, resulting in the origin of a new, derivative species.{{Citation|title=Rethinking classic examples of recent speciation in plants |author=L. D. Gottlieb |journal=New Phytologist |year=2003 |volume=161 |pages=71–82 |doi=10.1046/j.1469-8137.2003.00922.x |doi-access=free }}{{Citation|title=Chromosomal rearrangements and speciation |author=Loren H. Rieseberg |journal=Trends in Ecology & Evolution |year=2001 |volume=16 |issue=7 |pages=351–358 |doi= 10.1016/S0169-5347(01)02187-5 |pmid=11403867}} Evidence for the occurrence of this type of speciation has been found in several plant species pairs: Layia discoidea and L. glandulosa, Clarkia lingulata and C. biloba, and Stephanomeria malheurensis and S. exigua ssp. coronaria.

A closely related model of peripatric speciation is called budding speciation—largely applied in the context of plant speciation.{{Citation|title=The geography and ecology of plant speciation: range overlap and niche divergence in sister species |author=Brian L. Anacker and Sharon Y. Strauss |journal=Proceedings of the Royal Society B |year=2013 |volume=281 |issue=1778 |pages= 20132980|doi=10.1098/rspb.2013.2980 |pmid=24452025 |pmc=3906944 }} The budding process, where a new species originates at the margins of an ancestral range, is thought to be common in plants—especially in progenitor-derivative species pairs.{{Citation|title=Progenitor-derivative species pairs and plant speciation |author=Daniel J. Crawford |journal=Taxon |year=2010 |volume=59 |issue=5 |pages=1413–1423 |doi= 10.1002/tax.595008}}

William Louis Brown, Jr. proposed an alternative model of peripatric speciation in 1957 called centrifugal speciation. This model contrasts with peripatric speciation by virtue of the origin of the genetic novelty that leads to reproductive isolation.{{Citation |title=Patterns of Parapatric Speciation |author=Sergey Gavrilets, Hai Li, & Michael D. Vose |journal=Evolution |year=2000 |volume=54 |issue=4 |pages=1126–1134 |doi=10.1554/0014-3820(2000)054[1126:pops]2.0.co;2|pmid=11005282 |citeseerx=10.1.1.42.6514 |s2cid=198153997 }} A population of a species experiences periods of geographic range expansion followed by periods of contraction. During the contraction phase, fragments of the population become isolated as small refugial populations on the periphery of the central population. Because of the large size and potentially greater genetic variation within the central population, mutations arise more readily. These mutations are left in the isolated peripheral populations, promoting reproductive isolation. Consequently, Brown suggested that during another expansion phase, the central population would overwhelm the peripheral populations, hindering speciation. However, if the species finds a specialized ecological niche, the two may coexist.{{cite book |author=Daniel J. Howard |title=Encyclopedia of Life Sciences |chapter=Speciation: Allopatric |journal=eLS |date=2003 |doi=10.1038/npg.els.0001748|isbn=978-0470016176 }}{{Citation |title=Centrifugal speciation |author=W. L. Brown Jr. |journal=Quarterly Review of Biology |year=1957 |volume=32 |issue=3 |pages=247–277 |doi=10.1086/401875|s2cid=225071133 }} The phylogenetic signature of this model is that the central population becomes derived, while the peripheral isolates stay plesiomorphic—the reverse of the general model. In contrast to centrifugal speciation, peripatric speciation has sometimes been referred to as centripetal speciation (see figures 1 and 2 for a contrast).{{Citation |title=Interview with John C. Briggs, recipient of the 2005 Alfred Russel Wallace award |url=https://escholarship.org/uc/item/8jg516kj |author=Brian W. Bowen |journal=Frontiers of Biogeography |year=2010 |volume=2 |issue=3 |pages=78–80 |issn=1948-6596 }} Centrifugal speciation has been largely ignored in the scientific literature, often dominated by the traditional model of peripatric speciation.{{Citation |title=Centrifugal speciation and centres of origin |author=John C. Briggs |journal=Journal of Biogeography |year=2000 |volume=27 |issue=5 |pages=1183–1188 |doi=10.1046/j.1365-2699.2000.00459.x|bibcode=2000JBiog..27.1183B |s2cid=86734208 }} Despite this, Brown cited a wealth of evidence to support his model, of which has not yet been refuted.

Peromyscus polionotus and P. melanotis (the peripherally isolated species from the central population of P. maniculatus) arose via the centrifugal speciation model.{{Citation |title=Chromosomal Evolution and the Mode of Speciation in Three Species of Peromyscus |author=Ira F. Greenbaum, Robert J. Baker & Paul R. Ramsey |journal=Evolution |year=1978 |volume=32 |issue=3 |pages=646–654 |pmid=28567964 |doi=10.1111/j.1558-5646.1978.tb04609.x |s2cid=27865356 |doi-access=free }} Centrifugal speciation may have taken place in tree kangaroos, South American frogs (Ceratophrys), shrews (Crocidura), and primates (Presbytis melalophos). John C. Briggs associates centrifugal speciation with centers of origin, contending that the centrifugal model is better supported by the data, citing species patterns from the proposed 'center of origin' within the Indo-West Pacific

File:Kaneshiro Peripatric Speciation (process).png

The Kaneshiro Model also provides an explanation of the mechanism of speciation during founder events as proposed by Ernst Mayr and Hampton Carson. In most cases, founder events result when single fertilized female is accidentally translocated to an entirely different location, e.g., an adjacent island among a chain of islands such as the Hawaiian Archipelago, and produces a few offspring. Such a founder colony is faced with extremely small population size which as described by the Kaneshiro Model, experiences a shift in the mating system towards and increase in frequency of less choosy females. The resulting destabilization of the genetic system provides the milieu for new genetic variants to arise providing the recipe for speciation to occur. Eventually, a growth in population size paired with novel female mate preferences will give rise to reproductive isolation from the main population-thereby completing the speciation process. Support for this model comes from experiments and observation of species that exhibit asymmetric mating patterns such as the Hawaiian Drosophila species{{Citation |title=Sexual selection and direction of evolution in the biosystematics of Hawaiian Drosophilidae |author=Kenneth Y. Kaneshiro |journal=Annual Review of Entomology |year=1983 |volume=28 |pages=161–178 |doi=10.1146/annurev.en.28.010183.001113}}{{Citation |title=Behavioral Phylogenies and the Direction of Evolution |author=Luther Val Giddings & Alan R. Templeton |journal=Science |year=1983 |volume=220 |issue=4595 |pages=372–378 |doi=10.1126/science.220.4595.372 |pmid=17831399 |bibcode=1983Sci...220..372G |s2cid=45100702 }} or the Hawaiian cricket Laupala.{{Citation |title=Mating asymmetry and the direction of evolution in the Hawaiian cricket genus Laupala |author=Kerry L. Shaw & Ezequiel Lugo |journal=Molecular Ecology |year=2001 |volume=10 |issue=3 |pages=751–759 |doi=10.1046/j.1365-294x.2001.01219.x |pmid=11298985 |bibcode=2001MolEc..10..751S |s2cid=38590572 }} However, while laboratory experiments are ongoing and yet to be completed in support of the model, there are field observations of shifts in the mating systems that undergo population bottlenecks which demonstrate that the dynamics of sexual selection is occurring in nature and therefore, it does represent a plausible process of peripatric speciation that takes place in nature.

{{see also|Allopatric speciation#Observational evidence}}

Observational evidence and laboratory experiments support the occurrence of peripatric speciation. Islands and archipelagos are often the subject of speciation studies in that they represent isolated populations of organisms. Island species provide direct evidence of speciation occurring peripatrically in such that, "the presence of endemic species on oceanic islands whose closest relatives inhabit a nearby continent" must have originated by a colonization event.{{rp|106–107}} Comparative phylogeography of oceanic archipelagos shows consistent patterns of sequential colonization and speciation along island chains, most notably on the Azores islands, Canary Islands, Society Islands, Marquesas Islands, Galápagos Islands, Austral Islands, and the Hawaiian Islands—all of which express geological patterns of spatial isolation and, in some cases, linear arrangement.{{Citation |title=Comparative phylogeography of oceanic archipelagos: Hotspots for inferences of evolutionary process |author=Kerry L. Shaw & Rosemary G. Gillespie |journal=PNAS |year=2016 |volume=113 |issue=29 |pages=7986–7993 |doi=10.1073/pnas.1601078113 |pmid=27432948 |pmc=4961166 |bibcode=2016PNAS..113.7986S |doi-access=free }} Peripatric speciation also occurs on continents, as isolation of small populations can occur through various geographic and dispersion events. Laboratory studies have been conducted where populations of Drosophila, for example, are separated from one another and evolve in reproductive isolation.

{{multiple image|direction=vertical |width=300 |image1=Hawaii speciation (Drosophila and Cyanea colonization).png |caption1=Colonization events of species from the genus Cyanea (green) and species from the genus Drosophila (blue) on the Hawaiian island chain. Islands age from left to right, (Kauai being the oldest and Hawaii being the youngest). Speciation arises peripatrically as they spatiotemporally colonize new islands along the chain. Lighter blue and green indicate colonization in the reverse direction from young-to-old. |image2=Theridion grallator colonization pattern (Hawaiian volcano populations).png |caption2=A map of the Hawaiian archipelago showing the colonization routes of Theridion grallator superimposed. Purple lines indicate colonization occurring in conjunction with island age where light purple indicates backwards colonization. T. grallator is not present on Kauai or Niihau so colonization may have occurred from there, or the nearest continent.|image3=Elepaio colonization of Hawaiian archipelago.png |caption3=The sequential colonization and speciation of the ‘Elepaio subspecies along the Hawaiian island chain.}}

Drosophila species on the Hawaiian archipelago have helped researchers understand speciation processes in great detail. It is well established that Drosophila has undergone an adaptive radiation into hundreds of endemic species on the Hawaiian island chain;{{rp|107}}{{Citation |title=Modes and Mechanisms of Speciation |author=Hannes Schuler, Glen R. Hood, Scott P. Egan, & Jeffrey L. Feder |editor1-first=Robert A |editor1-last=Meyers |journal=Reviews in Cell Biology and Molecular Medicine |year=2016 |volume=2 |issue=3 |pages=60–93 |doi=10.1002/3527600906 |isbn=9783527600908 }} originating from a single common ancestor (supported from molecular analysis).DeSalle R. (1995). Molecular approaches to biogeographic analysis of Hawaiian Drosophilidae. Pp. 72-89 in W.L. Wagner and V.A. Funk (eds.) Hawaiian Biogeography: Evolution on a Hot-Spot Archipeligo. Smithsonian Institution Press, Washington DC. Studies consistently find that colonization of each island occurred from older to younger islands, and in Drosophila, speciating peripatrically at least fifty percent of the time.{{rp|108}} In conjunction with Drosophila, Hawaiian lobeliads (Cyanea) have also undergone an adaptive radiation, with upwards of twenty-seven percent of extant species arising after new island colonization—exemplifying peripatric speciation—once again, occurring in the old-to-young island direction.{{cite journal|title=Adaptive plant evolution on islands: classical patterns, molecular data, new insights |author=T. J. Givnish |journal=Evolution on Islands |year=1998 |volume=281 |page=304 }}T. J. Givnish, K. J. Sytsma, W. J. Hahn, and J. F. Smith. (1995). Molecular evolution, adaptive radiation, and geographic speciation in Cyanea (Campanulaceae, Lobeliodeae). Pp. 259-301 in W.L. Wagner and V.A. Funk (eds.) Hawaiian Biogeography: Evolution on a Hot-Spot Archipeligo. Smithsonian Institution Press, Washington DC.{{Citation |title=Origin, adaptive radiation and diversification of the Hawaiian lobeliads (Asterales: Campanulaceae) |author=Thomas J. Givnish, Kendra C. Millam, Austin R. Mast, Thomas B. Paterson, Terra J. Theim, Andrew L. Hipp, Jillian M. Henss, James F. Smith, Kenneth R. Wood, & Kenneth J. Sytsma |journal=Proc. R. Soc. B |year=2009 |volume=276 |issue= 1656|pages=407–416 |doi= 10.1098/rspb.2008.1204|pmid=18854299 |pmc=2664350 }}

Other endemic species in Hawaii also provide evidence of peripatric speciation such as the endemic flightless crickets (Laupala). It has been estimated that, "17 species out of 36 well-studied cases of [Laupala] speciation were peripatric".{{rp|108}}{{Citation |title=Conflict between nuclear and mitochondrial DNA phylogenies of a recent species radiation: What mtDNA reveals and conceals about modes of speciation in Hawaiian crickets| author=Kerry L. Shaw| journal=PNAS| year=2002| volume=99| issue=25| pages=16122–16127| doi=10.1073/pnas.242585899| pmid=12451181| pmc=138575| bibcode=2002PNAS...9916122S| doi-access=free}} Plant species in genera's such as Dubautia, Wilkesia, and Argyroxiphium have also radiated along the archipelago.{{Citation |title=Evolution in the Madiinae: Evidence from Enzyme Electrophoresis |author=Martha S. Witter |journal=Annals of the Missouri Botanical Garden |year=1990 |volume=77 |issue=1 |pages=110–117 |doi=10.2307/2399630|jstor=2399630 |url=https://www.biodiversitylibrary.org/part/7543 }} Other animals besides insects show this same pattern such as the Hawaiian amber snail (Succinea caduca),{{Citation |title=A geographic mosaic of passive dispersal: population structure in the endemic Hawaiian amber snail Succinea caduca (Mighels, 1845) |author=Brenden S. Holland and Robert H. Cowie |journal=Molecular Ecology |year=2007 |volume=16 |issue= 12|pages=2422–2435 |doi=10.1111/j.1365-294X.2007.03246.x |pmid=17561903 |bibcode=2007MolEc..16.2422H |s2cid=32193624 }} and ‘Elepaio flycatchers.{{Citation |title=Stepping stone speciation in Hawaii's flycatchers: molecular divergence supports new island endemics within the elepaio |author=Eric A. VanderWerf, Lindsay C. Young, Norine W. Yeung, & David B. Carlon |journal=Conservation Genetics |year=2010 |volume=11 |issue= 4|pages=1283–1298 |doi=10.1007/s10592-009-9958-1 |bibcode=2010ConG...11.1283V |s2cid=35883704 }}

Tetragnatha spiders have also speciated peripatrically on the Hawaiian islands,Rosemary G. Gillespie & H. B. Croom. (1995). Comparison of speciation mechanisms in web-building and non-web-building groups within a lineage of spiders. In W.L. Wagner & V.A. Funk (eds.) Hawaiian Biogeography: Evolution on a Hot-Spot Archipeligo, Smithsonian Institution Press, Washington DC. Pp. 121-146.{{Citation |title=Geographical context of speciation in a radiation of Hawaiian Tetragnatha spiders (Aranae, Tetragnathidae |author=Rosemary G. Gillespie |journal=The Journal of Arachnology |year=2005 |volume=33 |issue=2 |pages=313–322 |doi=10.1636/05-15.1|s2cid=11856750 |url=https://www.biodiversitylibrary.org/part/228841 }} Numerous arthropods have been documented existing in patterns consistent with the geologic evolution of the island chain, in such that, phylogenetic reconstructions find younger species inhabiting the geologically younger islands and older species inhabiting the older islands{{Citation |title=Community Assembly Through Adaptive Radiation in Hawaiian Spiders |author=Rosemary G. Gillespie |journal=Science |year=2004 |volume=303 |issue=5656 |pages=356–359 |doi=10.1126/science.1091875 |pmid=14726588 |bibcode=2004Sci...303..356G |s2cid=7748888 }} (or in some cases, ancestors date back to when islands currently below sea level were exposed). Spiders such as those from the genus Orsonwelles exhibit patterns compatible with the old-to-young geology.{{Citation |title=Speciation on a Conveyor Belt: Sequential Colonization of the Hawaiian Islands by Orsonwelles Spiders (Araneae, Linyphiidae) |author=Gustavo Hormiga, Miquel Arnedo, and Rosemary G. Gillespie |journal=Systematic Biology |year=2003 |volume=52 |issue=1 |pages=70–88 |doi=10.1080/10635150390132786 |pmid=12554442 |doi-access=free }} Other endemic genera such as Argyrodes have been shown to have speciated along the island chain.Rosemary G. Gillespie, Malia A. J. Rivera, & Jessica E. Garb. (1998). Sun, surf and spiders: taxonomy and phylogeography of Hawaiian Araneae. Proceedings of the 17th European Colloquium of Arachnology. Pagiopalus, Pedinopistha, and part of the family Thomisidae have adaptively radiated along the island chain,{{Citation |title=An Adaptive Radiation of Hawaiian Thomisidae: Biogreographic and Genetic Evidence| author=Jessica E. Garb |journal=The Journal of Arachnology |year=1999 |volume=27 |pages=71–78 }} as well as the wolf spider family, Lycosidae.{{Citation |title=The cavernicolous fauna of Hawaiian lava tubes. 3. Araneae (Spiders) |author=W. J. Gertsch |journal=Pacific Insects |year=1973 |volume=15 |pages=163–180}}

A host of other Hawaiian endemic arthropod species and genera have had their speciation and phylogeographical patterns studied: the Drosophila grimshawi species complex,{{Citation |title=Phylogeny of the Island Populations of the Hawaiian Drosophila grimshawi Complex: Evidence from Combined Data |author=Fabio Piano, Elysse M. Craddock, & Michael P. Kambysellis |journal=Molecular Phylogenetics and Evolution |year=1997 |volume=7 |issue=2 |pages=173–184 |doi= 10.1006/mpev.1996.0387|pmid=9126558 |doi-access=free |bibcode=1997MolPE...7..173P }} damselflies (Megalagrion xanthomelas and Megalagrion pacificum),{{Citation |title=Phylogeographic patterns of Hawaiian Megalagrion damselflies (Odonata: Coenagrionidae) correlate with Pleistocene island boundaries |author=Steve Jordan, Chris Simon, David Foote, and Ronald A. Englund |journal=Molecular Ecology |year=2005 |volume=14 |issue= 11|pages=3457–3470 |doi=10.1111/j.1365-294X.2005.02669.x |pmid=16156815 |bibcode=2005MolEc..14.3457J |s2cid=42614215 }} Doryonychus raptor, Littorophiloscia hawaiiensis, Anax strenuus, Nesogonia blackburni, Theridion grallator,{{Citation |title=Colonization history and population genetics of the color-polymorphic Hawaiian happy-face spider Theridion grallator (Araneae, Theridiidae) |author=Peter J. P. Croucher, Geoff S. Oxford, Athena Lam, Neesha Mody, & Rosemary G. Gillespie |journal=Evolution |year=2012 |volume=66 |issue=9 |pages=2815–2833 |doi=10.1111/j.1558-5646.2012.01653.x|pmid=22946805 |s2cid=28684202 |doi-access=free }} Vanessa tameamea, Hyalopeplus pellucidus, Coleotichus blackburniae, Labula, Hawaiioscia, Banza (in the family Tettigoniidae), Caconemobius, Eupethicea, Ptycta, Megalagrion, Prognathogryllus, Nesosydne, Cephalops, Trupanea, and the tribe Platynini—all suggesting repeated radiations among the islands.{{Citation |title=Speciation and phylogeography of Hawaiian terrestrial arthropods |author=G. K. Roderick & R. G. Gillespie |journal=Molecular Ecology |year=1998 |volume=7 |issue=4 |pages=519–531 |doi=10.1046/j.1365-294x.1998.00309.x|pmid=9628003 |bibcode=1998MolEc...7..519R |s2cid=29359389 }}

Phylogenetic studies of a species of crab spider (Misumenops rapaensis) in the genus Thomisidae located on the Austral Islands have established the, "sequential colonization of [the] lineage down the Austral archipelago toward younger islands". M. rapaensis has been traditionally thought of as a single species; whereas this particular study found distinct genetic differences corresponding to the sequential age of the islands.{{Citation |title=Island hopping across the central Pacific: mitochondrial DNA detects sequential colonization of the Austral Islands by crab spiders (Araneae: Thomisidae) |author=Jessica E. Garb & Rosemary G. Gillespie |journal=Journal of Biogeography |year=2006 |volume=33 |issue= 2| pages=201–220 |doi=10.1111/j.1365-2699.2005.01398.x |bibcode=2006JBiog..33..201G |s2cid=43087290 }} The figwart plant species Scrophularia lowei is thought to have arisen through a peripatric speciation event, with the more widespread mainland species, Scrophularia arguta dispersing to the Macaronesian islands.{{Citation|title=Peripatric speciation in an endemic Macaronesian plant after recent divergence from a widespread relative |author=Francisco J. Valtueña, Tomás Rodríguez-Riaño, Josefa López, Carlos Mayo, and Ana Ortega-Olivencia |journal=PLOS ONE |year=2017 |volume=12 |issue=6 |pages=e0178459 |doi=10.1371/journal.pone.0178459 |pmid=28575081 |pmc=5456078 |bibcode=2017PLoSO..1278459V |doi-access=free }}{{Citation|title=Scrophularia arguta, a widespread annual plant in the Canary Islands: a single recent colonization event or a more complex phylogeographic pattern? |author=Francisco J. Valtueña, Josefa López, Juan Álvarez, Tomás Rodríguez-Riaño, and Ana Ortega-Olivencia |journal=Ecology and Evolution |year=2016 |volume=6 |issue=13 |pages=4258–4273 |doi=10.1002/ece3.2109 |pmid=27386073 |pmc=4930978 |bibcode=2016EcoEv...6.4258V }} Other members of the same genus have also arisen by single colonization events between the islands.{{Citation|title=Multiple windows of colonization to Macaronesia by the dispersal-unspecialized Scrophularia since the Late Miocene |author=María L. Navarro-Péreza, Pablo Vargas, Mario Fernández-Mazuecos, Josefa López, Francisco J. Valtueña, and Ana Ortega-Olivencia |journal=Perspectives in Plant Ecology, Evolution and Systematics |year=2015 |volume=17 |issue=4 |pages=263–273 |doi=10.1016/j.ppees.2015.05.002 |bibcode=2015PPEES..17..263N }}{{Citation|title=Diversification of Scrophularia (Scrophulariaceae) in the Western Mediterranean and Macaronesia – Phylogenetic relationships, reticulate evolution and biogeographic patterns |author=AgnesScheunert and Günther Heubl |journal=Molecular Phylogenetics and Evolution |year=2014 |volume=70 |pages=296–313 |doi=10.1016/j.ympev.2013.09.023 |pmid=24096055 |bibcode=2014MolPE..70..296S }}

{{multiple image|align=left |direction=vertical |width=220 |image1=Sciaphylax hemimelaena - Southern chestnut-tailed antbird (male).jpg |caption1=The southern chestnut-tailed antbird, Sciaphylax hemimelaena |image2=Bolivia - Noel Kempff Mercado National Park (forest isolate).png |caption2=Satellite image of the Noel Kempff Mercado National Park (outlined in green) in Bolivia, South America. The white arrow indicates the location of the isolated forest fragment.}}

The occurrence of peripatry on continents is more difficult to detect due to the possibility of vicariant explanations being equally likely.{{rp|110}} However, studies concerning the Californian plant species Clarkia biloba and C. lingulata strongly suggest a peripatric origin.{{Citation |title=The origin of Clarkia lingulata|author=H. Lewis & M. R. Roberts |journal=Evolution |year=1956 |volume=10 |issue=2 |pages=126–138 |doi=10.2307/2405888|jstor=2405888 }} In addition, a great deal of research has been conducted on several species of land snails involving chirality that suggests peripatry (with some authors noting other possible interpretations).{{rp|111}}

The chestnut-tailed antbird (Sciaphylax hemimelaena) is located within the Noel Kempff Mercado National Park (Serrania de Huanchaca) in Bolivia. Within this region exists a forest fragment estimated to have been isolated for 1000–3000 years. The population of S. hemimelaena antbirds that reside in the isolated patch express significant song divergence; thought to be an "early step" in the process of peripatric speciation. Further, peripheral isolation "may partly explain the dramatic diversification of suboscines in Amazonia".

The montane spiny throated reed frog species complex (genus: Hyperolius) originated through occurrences of peripatric speciation events. Lucinda P. Lawson maintains that the species' geographic ranges within the Eastern Afromontane Biodiversity Hotspot support a peripatric model that is driving speciation; suggesting that this mode of speciation may play a significant role in "highly fragmented ecosystems".

In a study of the phylogeny and biogeography of the land snail genus Monacha, the species M. ciscaucasica is thought to have speciated peripatrically from a population of M. roseni. In addition, M. claussi consists of a small population located on the peripheral of the much larger range of M. subcarthusiana suggesting that it also arose by peripatric speciation.{{Citation |title=Molecular phylogeny and biogeography of the land snail genus Monacha (Gastropoda, Hygromiidae) |author=Marco T. Neiber & Bernhard Hausdorf |journal=Zoologica Scripta |volume=46 |issue=3 |year=2016 |pages=1–14 |doi=10.1111/zsc.12218 |s2cid=88655961 }}

{{multiple image|align=right |image1=Picea mariana cones.jpg |width1=800 |caption1=Foliage and cones of Picea mariana |image2=Picea rubens UGA5349098.jpg |width2=800 |caption2=Foliage and cones of Picea rubens |total_width=350 |height1=500 |height2=500}}

Red spruce (Picea rubens) has arisen from an isolated population of black spruce (Picea mariana). During the Pleistocene, a population of black spruce became geographically isolated, likely due to glaciation. The geographic range of the black spruce is much larger than the red spruce. The red spruce has significantly lower genetic diversity in both its DNA and its mitochondrial DNA than the black spruce.{{Citation |title=Genetic diversity and population structure of red spruce (Picea rubens) |author=Gary J. Hawley & Donald H. DeHayes |journal=Canadian Journal of Botany |year=1994 |volume=72 |issue=12 |pages=1778–1786 |doi=10.1139/b94-219 }}{{Citation |title=New evidence from mitochondrial DNA of a progenitor-derivative species relationship between black and red spruce (Pinaceae) |author=Juan P. Jaramillo-Correa & Jean Bousquet |journal=American Journal of Botany |year=2003 |volume=90 |issue=12 |pages=1801–1806 |doi= 10.3732/ajb.90.12.1801 |pmid=21653356}} Furthermore, the genetic variation of the red spruce has no unique mitochondrial haplotypes, only subsets of those in the black spruce; suggesting that the red spruce speciated peripatrically from the black spruce population.{{Citation |title=Cross-species amplification of mitochondrial DNA sequence-tagged-site markers in conifers: the nature of polymorphism and variation within and among species in Picea |author=J. P. Jaramillo-Correa, J. Bousquet, J. Beaulieu, N. Isabel, M. Perron, & M. Bouillé |journal=Theoretical and Applied Genetics |year=2003 |volume=106 |issue= 8| pages=1353–1367 |doi=10.1007/s00122-002-1174-z |pmid=12750779 |s2cid=21097661 }}{{Citation |title=Diverging patterns of mitochondrial and nuclear DNA diversity in subarctic black spruce: imprint of a founder effect associated with postglacial colonization |author=Isabelle Gamache, Juan P. Jaramillo-Correa, Sergey Payette, & Jean Bousquet |journal=Molecular Ecology |year=2003 |volume=12 |issue= 4|pages=891–901 |doi=10.1046/j.1365-294x.2003.01800.x|pmid=12753210 |bibcode=2003MolEc..12..891G |s2cid=20234158 }}{{Citation |title=Evidence from sequence-tagged-site markers of a recent progenitor-derivative species pair in conifers |author=Martin Perron, Daniel J. Perry, Christophe Andalo, & Jean Bousquet |journal=PNAS |year=2000 |volume=97 |issue=21 |pages=11331–11336 |doi=10.1073/pnas.200417097|pmid=11016967 |pmc=17200 |bibcode=2000PNAS...9711331P |doi-access=free }} It is thought that the entire genus Picea in North America has diversified by the process of peripatric speciation, as numerous pairs of closely related species in the genus have smaller southern population ranges; and those with overlapping ranges often exhibit weak reproductive isolation.{{Citation |title=Species crossability in Spruce in relation to distribution and taxonomy |author=J. W. Wright|journal=Forest Science |year=1955 |volume=1 |issue=4 |pages=319–349 }}

Using a phylogeographic approach paired with ecological niche models (i.e. prediction and identification of expansion and contraction species ranges into suitable habitats based on current ecological niches, correlated with fossil and molecular data), researchers found that the prairie dog species Cynomys mexicanus speciated peripatrically from Cynomys ludovicianus approximately 230,000 years ago. North American glacial cycles promoted range expansion and contraction of the prairie dogs, leading to the isolation of a relic population in a refugium located in the present day Coahuila, Mexico.{{Citation |title=Peripatric speciation of an endemic species driven by Pleistocene climate change: The case of the Mexican prairie dog (Cynomys mexicanus) |author=Gabriela Castellanos-Morales, Niza Gámez, Reyna A. Castillo-Gámez, & Luis E. Eguiarte| journal=Molecular Phylogenetics and Evolution |year=2016 |volume=94 |issue=Pt A|pages=171–181 |doi=10.1016/j.ympev.2015.08.027 |pmid=26343460|bibcode=2016MolPE..94..171C }} This distribution and paleobiogeographic pattern correlates with other species expressing similar biographic range patterns such as with the Sorex cinereus complex.{{Citation |title=A climate for speciation: Rapid spatial diversification within the Sorex cinereus complex of shrews |author=Andrew G. Hope, Kelly A. Speer, John R. Demboski, Sandra L. Talbot, & Joseph A. Cook |journal=Molecular Phylogenetics and Evolution |year=2012 |volume=64 |issue= 3|pages=671–684 |doi=10.1016/j.ympev.2012.05.021 |pmid=22652055 |bibcode=2012MolPE..64..671H }}

{{see also|Laboratory experiments of speciation}}

Peripatric speciation has been researched in both laboratory studies and nature. Jerry Coyne and H. Allen Orr in Speciation suggest that most laboratory studies of allopatric speciation are also examples of peripatric speciation due to their small population sizes and the inevitable divergent selection that they undergo.{{rp|106}} Much of the laboratory research concerning peripatry is inextricably linked to founder effect research. Coyne and Orr conclude that selection's role in speciation is well established, whereas genetic drift's role is unsupported by experimental and field data—suggesting that founder-effect speciation does not occur.{{rp|410}} Nevertheless, a great deal of research has been conducted on the matter, and one study conducted involving bottleneck populations of Drosophila pseudoobscura found evidence of isolation after a single bottleneck.{{Citation |title=The Founder-Flush Speciation Theory: An Experimental Approach| author=Jeffrey R. Powell |journal=Evolution |year=1978 |volume=32 |issue=3 |pages=465–474 |pmid=28567948|doi=10.1111/j.1558-5646.1978.tb04589.x| s2cid=30943286 |doi-access=free }}{{Citation |title=Founder-Flush Speciation: An Update of Experimental Results with Drosophila|author=Diane M. B. Dodd & Jeffrey R. Powell |journal=Evolution |year=1985 |volume=39 |issue=6 |pages=1388–1392 |pmid=28564258 |doi=10.1111/j.1558-5646.1985.tb05704.x|s2cid=34137489 |doi-access=free }}

The table is a non-exhaustive table of laboratory experiments focused explicitly on peripatric speciation. Most of the studies also conducted experiments on vicariant speciation as well. The "replicates" column signifies the number of lines used in the experiment—that is, how many independent populations were used (not the population size or the number of generations performed).

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