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Topic: Sympatric speciation

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In the News (Sat 20 Apr 19)

  Sympatric/parapatric speciation, hybrid zones, and reinforcement (October 2002)   (Site not responding. Last check: 2007-09-17)
Parapatric hybridization in the chromosomal speciation of the house mouse.
Hybridization and speciation in the carabid beetles of the subgenus Ohomopterus (Coleoptera, Carabidae, genus Carabus).
Sympatric morphs, populations and speciation in freshwater fish with emphasis on arctic charr.
www.eeb.uconn.edu /Courses/EEB449/449_sympatric.htm   (9075 words)

 Speciation - Wikipedia, the free encyclopedia
Speciation is the evolutionary process by which new biological species arise.
3 Gene transposition as a cause of speciation
Examples of sympatric speciation are found in insects which become dependent on different host plants in the same area.
en.wikipedia.org /wiki/Speciation   (1532 words)

Ecosystem diversity describes the variety of habitats present; species diversity is a measure of the number of species and the number of individuals of each species present; genetic diversity refers to the total amount of genetic variability present.
The difference between the form of a molecule in two species is then proportional to the time since the species diverged from a common ancestor, and molecules become of great value in the inference of phylogeny.
The species included in the group are those that have continued to resemble the ancestor; the excluded species have evolved rapidly and no longer resemble their ancestor.
www.pbs.org /wgbh/evolution/library/glossary/glossary.html   (15490 words)

Sympatric speciation can occur more readily in plants (Savolainen et al., 2006), because plants can change their chrosome number (polyploidy) and persist or spread by asexual reproduction.
In such species, both mates compete intensively for scarce resources (e.g., nesting cavities for toucans and burrows for puffins) as well as for access to the best mates of the opposite sex (both sexes compete for mates and both parents invest heavily in parental care).
Sympatric speciation in palms on an oceanic island.
www.uwyo.edu /dbmcd/molmark/lect2a.html   (3205 words)

 Levels of Selection, and Speciation Mechanisms, Barry Sinervo
One species or both species refuse to engage in the mating rituals because the stereotyped mating rituals are to different.
Sympatric speciation is the origin of two new species with the two forms in the same place.
A key aspect of the theory of sympatric speciation involves the process of natural selection that favors the evolution of discrimination on the part of the female and also the divergence of male traits that females use for mate discrimination.
bio.research.ucsc.edu /~barrylab/classes/animal_behavior/SPECIATE.HTM   (6803 words)

 Sympatric speciation - Wikipedia, the free encyclopedia
In complete contrast to allopatry, species undergoing sympatric speciation are not geographically isolated by, for example, a mountain or a river.
The apple feeding race of this species appears to have spontaneously emerged from the hawthorn feeding race in the 1800 - 1850 AD time frame, after apples were first introduced into North America.
Sympatric speciation events are most common in plants when they double or triple the number of chromosomes, resulting in a condition called polyploidy.
en.wikipedia.org /wiki/Sympatric_speciation   (396 words)

 Allopatric vs
Therefore, sympatric speciation is not only possible, but likely contributes to much of the diversity seen in nature.
This species has recently diverged into two subspecies due to the introduction of apple trees in the northeastern United States, where hawthorn trees were native.
Furthermore, empirical studies have demonstrated that sympatric speciation can cause the divergence of a population in a relatively short amount of time; allopatric speciation requires much more time, especially in large populations.
evotutor.org /Author/Research/Paper-EG2-Speciation.htm   (983 words)

 Observed Instances of Speciation
Part 2 discusses several definitions of what a species is. Part 3 explains the context in which observations of speciation are made.
A species is the smallest cluster of organisms that possesses at least one diagnostic character.
A species of hemp nettle, Galeopsis tetrahit, was hypothesized to be the result of a natural hybridization of two other species, G. pubescens and G. speciosa (Muntzing 1932).
www.talkorigins.org /faqs/faq-speciation.html   (9153 words)

Founder effect speciation is an extreme form of subdivision in species formation takes place in a small isolated population.
The evolution of such divergence, in the face of gene flow is a tremendous challenge for the evolution of species by the process of sympatric speciation.
In a classic population genetic analysis, Felsenstein (1981) showed that the process of sympatric speciation is a fairly unlikely event.
bio.research.ucsc.edu /~barrylab/classes/evolution/SPECIES.HTM   (2335 words)

 Frontiers in Zoology | Full text | Reticulate sympatric speciation in Cameroonian crater lake cichlids
Recent empirical data and theoretical advances suggest that the diversity of complex species assemblages is based at least partially on the hybridization of numerous ancestral allopatric lineages that formed hybrids upon invasion of new environments [1-5].
These arguments in combination with an increasing body of evidence showing that species resulting from interspecific hybridization are common in plants [13] and highly probable in animals [5,7,9-14] gave rise to hypotheses about a prominent role of hybridization for the evolution of adaptive radiations [6].
Accordingly, one putative second species with a hybrid genome in the lake, Konia dikume, ranks among the most unusual cichlids as it is the single species which is able to exploit chironimid larvae in the almost oxygen-free deep water due to its extremely high haemoglobin concentration in its blood [32].
www.frontiersinzoology.com /content/1/1/5   (6135 words)

 Evolution: Library: Hummingbird Species in the Transitional Zones
The hummingbirds that live on the east slope of the Andes Mountains in Ecuador have adapted to a range of habitats, from steamy lowland rainforest to windswept alpine meadows.
Biologists Smith and Schneider, studying the differences between these adjacent populations, are finding that natural selection in different ecological niches has pushed the birds down different evolutionary paths and created new species, even though the populations have not been isolated from each other geographically.
The globe-trotting biologists are discovering an intriguing pattern: In many places, species appear to have emerged at the transition zones between different ecosystems, without ever being geographically cut off from the parent stock.
www.pbs.org /wgbh/evolution/library/05/2/l_052_04.html   (490 words)

as you travel from east to west in Europe, you discover that, in a species of green woodpecker, there is clinal variation in the shade of green on the back such that eastern woodpecker populations have pale green backs and back color becomes gradually darker, from population to population, as you go to the west.
Sympatric speciation is generally considered to be less likely than is allopatric speciation.
You suspect that speciation between them has occurred through the evolution of different mating behaviors, and want to test whether these behavioral changes have occurred through a large number of mutations, each with a relatively small impact on the behavioral phenotype, or through a small number of mutations, each with a large phenotypic impact.
www.utm.edu /departments/cens/biology/rirwin/391/391ManChXIII.htm   (1377 words)

 Some More Observed Speciation Events
A molecular reexamination of diploid hybrid speciation of Solanum raphanifolium.
Gottlieb, L. Genetic differentiation, sympatric speciation, and the origin of a diploid species of Stephanomeria.
Genus Rattus currently consists of 137 species [1,2] and is known to have originally developed in Indonesia and Malaysia during and prior to the Middle Ages [3].
www.talkorigins.org /faqs/speciation.html   (1472 words)

 Speciation: Going for a song
Though not as well known as the cuckoos, the African brood-parasitic finches are equally fascinating and differ in ways that lend insight into the evolutionary biology of both groups.
Sympatric speciation is the formation of descendant species from a single ancestral species in the same geographic location.
In the indigobird the key behavioural components in speciation are imprinting on host song, song mimicry in males and sexual selection in the form of female choice.
www.nature.com /nature/links/030821/030821-7.html   (153 words)

 BIO 304. Ecology & Evolution: Macroevolution
Accidental mistakes in oviposition site selection lead to the establishment of sympatric populations of this species that did not interbreed due to their high fidelity to their host plant.
Pollinator switching in species with highly specialized pollination mechanism may also lead to sympatric speciation.
The latter species was regarded as a variant of the former for long.
www.micro.utexas.edu /courses/levin/bio304/evolution/speciation.html   (498 words)

 Sympatric speciation in Nicaraguan crater lake cichlid fish : Nature
Sympatric speciation in Nicaraguan crater lake cichlid fish
Sympatric speciation, the formation of species in the absence of geographical barriers, remains one of the most contentious concepts in evolutionary biology.
Here we present a convincing case of sympatric speciation in the Midas cichlid species complex (Amphilophus sp.) in a young and small volcanic crater lake in Nicaragua.
www.nature.com /nature/journal/v439/n7077/abs/nature04325.html   (273 words)

 Sympatric speciation through intraspecific social parasitism -- Savolainen and Vepsäläinen 100 (12): 7169 -- ...
Sympatric speciation through intraspecific social parasitism -- Savolainen and Vepsäläinen 100 (12): 7169 -- Proceedings of the National Academy of Sciences
The three species groups shown with vertical lines are defined on the basis of worker morphology, excluding the inquilines (47).
fields of study of sympatric speciation of social parasites.
www.pnas.org /cgi/content/full/100/12/7169   (4015 words)

 Evolution 101: Speciation
Unlike the previous modes, sympatric speciation does not require large-scale geographic distance to reduce gene flow between parts of a population.
This host shift from hawthorns to apples may be the first step toward sympatric speciation—in fewer than 200 years, some genetic differences between these two groups of flies have evolved.
In general, selection for specialization would have to be extremely strong in order to cause the population to diverge.
evolution.berkeley.edu /evosite/evo101/VC1eSympatric.shtml   (338 words)

 SYMPATRIC SPECIATION   (Site not responding. Last check: 2007-09-17)
Speciation is sympatric if the two (or more) new species occur in the _______ place as the _________ species
In this case a new species is formed “______________________”
Sympatric speciation in animals is not as well documented but possible could result from
www.auburn.edu /academic/classes/biol/1000/speciation/tsld007.htm   (134 words)

 evolgen: Nick Barton and Jerry Coyne Don't Like Your Sympatric Speciation
Still, he questioned whether the species are truly sister taxa, and didn't reach the island or crater lake from separate invasions from a source population.
However, one of our best examples of sympatric speciation via chromosomal inversions is actually allopatric speciation with reinforcement.
This is a lot like sympatric speciation too and often leads to reproductive isolation that didn't exist BEFORE, of course reproductive isolation is not directly selected for here as it is with reinforcement.
scienceblogs.com /evolgen/2006/09/nick_barton_and_jerry_coyne_do.php   (652 words)

 Evolution 101: Speciation
The key to speciation is the evolution of genetic differences between the incipient species.
For a lineage to split once and for all, the two incipient species must have genetic differences that are expressed in some way that causes matings between them to either not happen or to be unsuccessful.
Modes of speciation are often classified according to how much the geographic separation of incipient species can contribute to reduced gene flow.
evolution.berkeley.edu /evosite/evo101/VC1aModesSpeciation.shtml   (156 words)

 Sympatric speciation under incompatibility selection -- Artzy-Randrup and Kondrashov 103 (31): 11619 -- Proceedings of ...
Sympatric speciation under incompatibility selection -- Artzy-Randrup and Kondrashov 103 (31): 11619 -- Proceedings of the National Academy of Sciences
The existing theory of sympatric speciation assumes that a local
the individuals are specialized to consume one of the resources.
www.pnas.org /cgi/content/short/103/31/11619?rss=1   (305 words)

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