Are ring species the same species?
They are as distinct as though they were two separate species. Yet the entire complex of populations belongs to a single taxonomic species, Ensatina escholtzii. Ring species, says biologist David Wake, who has studied Ensatina for more than 20 years, are a beautiful example of species formation in action.
What causes ring species?
A ring species is a monophyletic group whose range has expanded around a geographic barrier producing a ring-shaped distribution. Populations that make up the ring should be contiguous and without barriers to gene flow except at one location where two reproductively isolated populations co-occur.
Are ring species subspecies?
The subspecies that occur in western North America have been suggested to form a ring species.
What is an example of a ring species?
A ring species is a situation in which two populations which do not interbreed are living in the same region and connected by a geographic ring of populations that can interbreed. Famous examples of ring species are the herring and lesser black-backed gulls in northern Europe and the Ensatina salamanders of California.
What is species in biology?
A biological species is a group of organisms that can reproduce with one another in nature and produce fertile offspring.
Why is the phenomenon of ring species interesting to evolutionary biologists?
Such species are known as “ring species.” They're interesting for two reasons. First, they show that you can get the evolution of complete reproductive isolation without geographic isolation. Second it's a judgment call whether you call them one or two species.
How does a ring species illustrate speciation in action?
How does a ring species illustrate speciation in action? Some populations of a ring species are reproductively isolated, while others can hybridize. Which of the following best describes how allele frequencies changed from Year 1 to Year 2? They have become more similar.
What's sympatric mean?
occurring in the same area: occurring in the same area. : occupying the same geographical range without loss of identity from interbreeding. sympatric species. also : occurring between populations that are not geographically separated.
How does a ring species illustrate speciation in action?
How does a ring species illustrate speciation in action? Some populations of a ring species are reproductively isolated, while others can hybridize. Which of the following best describes how allele frequencies changed from Year 1 to Year 2? They have become more similar.
What is a ring species quizlet?
A ring species is a situation in which two populations which do not interbreed are living in the same region and connected by a geographic ring of populations that can interbreed.
How does speciation happen?
Speciation is the process by which new species form. It occurs when groups in a species become reproductively isolated and diverge. In allopatric speciation, groups from an ancestral population evolve into separate species due to a period of geographical separation.
Why is the phenomenon of ring species interesting to evolutionary biologists?
Such species are known as “ring species.” They're interesting for two reasons. First, they show that you can get the evolution of complete reproductive isolation without geographic isolation. Second it's a judgment call whether you call them one or two species.
What is a ring species?
The interbreeding populations are then called a ring species. In biology, a ring species is a connected series of neighbouring populations, each of which interbreeds with closely sited related populations, but for which there exist at least two "end" populations in the series, which are too distantly related to interbreed, ...
How do ring species differ from other species?
All that distinguishes a ring species from two separate species is the existence of the connecting populations; if enough of the connecting populations within the ring perish to sever the breeding connection then the ring species' distal populations will be recognized as two distinct species. The problem is whether to quantify the whole ring as a single species (despite the fact that not all individuals interbreed) or to classify each population as a distinct species (despite the fact that it interbreeds with its near neighbours). Ring species illustrate that species boundaries arise gradually and often exist on a continuum.
Why are ring species rare?
Ring species often attract the interests of evolutionary biologists, systematists, and researchers of speciation leading to both thought provoking ideas and confusion concerning their definition . Contemporary scholars recognize that examples in nature have proved rare due to various factors such as limitations in taxonomic delineation or, "taxonomic zeal" —explained by the fact that taxonomists classify organisms into "species", while ring species often cannot fit this definition. Other reasons such as gene flow interruption from "vicariate divergence" and fragmented populations due to climate instability have also been cited.
When did Mayr first discover the ring?
These and other discoveries led Mayr to first formulate a theory on ring species in his 1942 study Systematics and the Origin of Species.
Who championed the concept of ring species?
The biologist Ernst Mayr championed the concept of ring species, claiming that it unequivocally demonstrated the process of speciation. A ring species is an alternative model to allopatric speciation, "illustrating how new species can arise through 'circular overlap', without interruption of gene flow through intervening populations…".
Do species exist in nature?
Many examples have been documented in nature. Debate exists concerning much of the research, with some authors citing evidence against their existence entirely. The following examples provide evidence that—despite the limited number of concrete, idealized examples in nature—continuums of species do exist and can be found in biological systems. This is often characterized by sub-species level classifications such as clines, ecotypes, complexes, and varieties. Many examples have been disputed by researchers, and equally "many of the [proposed] cases have received very little attention from researchers, making it difficult to assess whether they display the characteristics of ideal ring species."
What is a ring species?
A ring species is a situation in which two populations which do not interbreed are living in the same region and connected by a geographic ring of populations that can interbreed.
How to imagine a ring species?
A ring species can be best imagined like this: Consider a species that is geographically distributed in a straight line from east to west across America: it is possible that the forms in the east and west are so different that they could not interbreed. Now imagine taking the line and bending it into a circle, such that the end points ...
What happens if a species does not interbreed?
If they do not interbreed then the geographic distribution of the species will be in the shape of a ring, and they will be 'ring species': the extreme forms do not interbreed in the region of overlap.
Explanation of the diagram
The coloured bar to the right shows a number of natural populations, each population represented by a different colour, varying along a cline (a gradual change in conditions which gives rise to slightly different characteristics predominating in the organisms that live along it).
Problem of definition
The problem, then, is whether to quantify the whole ring as a single species (despite the fact that not all individuals can interbreed) or to classify each population as a distinct species (despite the fact that it can interbreed with its near neighbours).
Larus gulls
A classic example of ring species is the Larus gulls circumpolar species "ring". The range of these gulls forms a ring around the North Pole.
Overview
In biology, a ring species is a connected series of neighbouring populations, each of which interbreeds with closely sited related populations, but for which there exist at least two "end" populations in the series, which are too distantly related to interbreed, though there is a potential gene flow between each "linked" population. Such non-breeding, though genetically connected, "end" populations may co-exist in the same region (sympatry) thus closing a "ring". The German t…
History
• The Larus gulls interbreed in a ring around the arctic. 1: L. fuscus, 2: Siberian population of L. fuscus, 3: L. heuglini, 4: L. vegae birulai, 5: L. vegae, 6: L. smithsonianus, 7: L. argentatus
• Herring gull (Larus argentatus) (front) and lesser black-backed gull (Larus fuscus) (behind) in Norway: two phenotypes with clear differences
Speciation
The biologist Ernst Mayr championed the concept of ring species, stating that it unequivocally demonstrated the process of speciation. A ring species is an alternative model to allopatric speciation, "illustrating how new species can arise through 'circular overlap', without interruption of gene flow through intervening populations…" However, Jerry Coyne and H. Allen Orr point out that rings species more closely model parapatric speciation.
Examples
Many examples have been documented in nature. Debate exists concerning much of the research, with some authors citing evidence against their existence entirely. The following examples provide evidence that—despite the limited number of concrete, idealized examples in nature—continuums of species do exist and can be found in biological systems. This is often characterized by sub-species level classifications such as clines, ecotypes, complexes, and varieti…
See also
• Dialect continuum, a similar concept in linguistics
• Intergradation
External links
• Greenish Warbler
• Greenish Warbler maps and songs
• Ensatina salamander
• Ring species – the abridged version on YouTube, by Peter Hadfield (potholer54)