Molecular evolution and the latitudinal
... from two main sampling strategies that use DNA sequences from extant species (usually represented by a single individual) to infer rate differences among lineages. Possible instances of punctuational evolution at nodes (grey boxes), extinct lineages (dashed lines), pruned or un-sampled lineages (X) ...
... from two main sampling strategies that use DNA sequences from extant species (usually represented by a single individual) to infer rate differences among lineages. Possible instances of punctuational evolution at nodes (grey boxes), extinct lineages (dashed lines), pruned or un-sampled lineages (X) ...
Felsenstein`s “one-allele model” of speciation: The role of philopatry
... homogenizing effects of gene flow and in fact may be spread across incipient species populations thereby increasing the rate of divergence. It is believed that while a one-allele model is more likely to lead to speciation with gene flow the conditions are too restrictive to be common. Recent work ha ...
... homogenizing effects of gene flow and in fact may be spread across incipient species populations thereby increasing the rate of divergence. It is believed that while a one-allele model is more likely to lead to speciation with gene flow the conditions are too restrictive to be common. Recent work ha ...
The polymorphic prelude to Bateson–Dobzhansky–Muller
... Speciation research has largely assumed that the genetic causes of reproductive isolation are the work of fixed, divergent alleles that interact to cause genetic problems in hybrids: Bateson–Dobzhansky–Muller incompatibilities. However, many recent studies demonstrate substantial heritable polymorph ...
... Speciation research has largely assumed that the genetic causes of reproductive isolation are the work of fixed, divergent alleles that interact to cause genetic problems in hybrids: Bateson–Dobzhansky–Muller incompatibilities. However, many recent studies demonstrate substantial heritable polymorph ...
Divergent Selection Drives Genetic Differentiation in an
... selection acting on the specific genes affecting reproductive isolation between divergent taxa. Relative to other forms of reproductive isolation, adaptations that reduce the frequency of mating among neighboring populations (i.e. pre-mating barriers) can have disproportionate effects on reducing ge ...
... selection acting on the specific genes affecting reproductive isolation between divergent taxa. Relative to other forms of reproductive isolation, adaptations that reduce the frequency of mating among neighboring populations (i.e. pre-mating barriers) can have disproportionate effects on reducing ge ...
Mallet, J. (2010). Group selection and the biological species
... maintained by selection to avoid breakdown of beneficial coadaptation and the ‘gene pool’. Speciation thus seemed difficult. It seemed to require, more so than today, an external deus ex machina, such as allopatry or the founder effect, rather than ordinary within-species processes of natural select ...
... maintained by selection to avoid breakdown of beneficial coadaptation and the ‘gene pool’. Speciation thus seemed difficult. It seemed to require, more so than today, an external deus ex machina, such as allopatry or the founder effect, rather than ordinary within-species processes of natural select ...
Group selection and the development of the biological species
... have continued to accept uncritically Mayr’s argument for ‘Darwin’s failure’ (Mallet in press). This twentieth century view that Darwin failed on species and speciation is particularly perplexing, because it came about as a result of the Modern Synthesis, a movement which championed Darwinian natura ...
... have continued to accept uncritically Mayr’s argument for ‘Darwin’s failure’ (Mallet in press). This twentieth century view that Darwin failed on species and speciation is particularly perplexing, because it came about as a result of the Modern Synthesis, a movement which championed Darwinian natura ...
PopGen4: Assortative mating
... Under a system of POSITIVE ASSORTATIVE MATING individuals choose mates that are phenotypically like themselves. Note that under random mating there will always be some fraction of the population that mate with phenotypically similar individuals. So when we say positive assortment, we mean that the m ...
... Under a system of POSITIVE ASSORTATIVE MATING individuals choose mates that are phenotypically like themselves. Note that under random mating there will always be some fraction of the population that mate with phenotypically similar individuals. So when we say positive assortment, we mean that the m ...
Evolving entities - Philosophical Transactions of the Royal Society B
... but for now assume that the sample includes several individuals from each of any distinct clusters found in the clade, and that individuals are sampled at random from within each cluster. The question then is what processes cause diversification into these distinct forms. (a) Reproductive isolation ...
... but for now assume that the sample includes several individuals from each of any distinct clusters found in the clade, and that individuals are sampled at random from within each cluster. The question then is what processes cause diversification into these distinct forms. (a) Reproductive isolation ...
Ecological Speciation Among Blue Holes in Mosquitofish
... and does not require selection to directly favor reproductive isolation (i.e., reinforcement). Theory suggests that divergent natural selection between environments might often result in speciation as a by-product, however only a handful of examples where this may occur have so far been revealed (e. ...
... and does not require selection to directly favor reproductive isolation (i.e., reinforcement). Theory suggests that divergent natural selection between environments might often result in speciation as a by-product, however only a handful of examples where this may occur have so far been revealed (e. ...
Coyne et al 2000 Evolution 54
... position is unreasonable. They assert, in particular, that we adhere to what they call ‘‘Fisher’s ‘large population size theory’ (LST),’’ which maintains that natural populations are not subdivided, allelic effects are independent of environmental and genetic backgrounds, and that speciation occurs ...
... position is unreasonable. They assert, in particular, that we adhere to what they call ‘‘Fisher’s ‘large population size theory’ (LST),’’ which maintains that natural populations are not subdivided, allelic effects are independent of environmental and genetic backgrounds, and that speciation occurs ...
Evolution and Speciation
... By the end of this section, you will be able to: • Explain how Darwin’s theory of evolution differed from the current view at the time • Describe how the present-day theory of evolution was developed • Describe how population genetics is used to study the evolution of populations The theory of evolu ...
... By the end of this section, you will be able to: • Explain how Darwin’s theory of evolution differed from the current view at the time • Describe how the present-day theory of evolution was developed • Describe how population genetics is used to study the evolution of populations The theory of evolu ...
CV - Molly Schumer
... Undergraduate Thesis Research: Gene expression, hormones, and behavior in a sex-role conventional and sex-role reversed cichlid species pair, 2008-2009 (research adviser: Professor Suzy C.P. Renn) Roswell Park Cancer Institute Research Assistant: The mechanisms of BMAL-dependent CLOCK phosphorylatio ...
... Undergraduate Thesis Research: Gene expression, hormones, and behavior in a sex-role conventional and sex-role reversed cichlid species pair, 2008-2009 (research adviser: Professor Suzy C.P. Renn) Roswell Park Cancer Institute Research Assistant: The mechanisms of BMAL-dependent CLOCK phosphorylatio ...
American Scientist
... that an increasing number of islands formed volcanically in the region of a western hotspot and in the region of a northern spreading center. As the number of islands increased, so did the number of finch species (Figure 5); we estimate the number of finch species by ignoring the unknown extinctions ...
... that an increasing number of islands formed volcanically in the region of a western hotspot and in the region of a northern spreading center. As the number of islands increased, so did the number of finch species (Figure 5); we estimate the number of finch species by ignoring the unknown extinctions ...
Linking Evolutionary Pattern and Process
... clusters would appear to have the advantage of being operational, because species are defined directly in terms of the distribution of character states rather than in terms of descent relationships or interbreeding inferred from such distributions. The genotypic clusters definition, however, can onl ...
... clusters would appear to have the advantage of being operational, because species are defined directly in terms of the distribution of character states rather than in terms of descent relationships or interbreeding inferred from such distributions. The genotypic clusters definition, however, can onl ...
Rapid Post-Flood Speciation: A Critique of the Young
... evidence, they point to populations of mosquitoes, salmon and other creatures that no longer interbreed with their main populations.50,51 However, these are examples of reproductive isolation-as subpopulations get isolated they often won't interbreed with the main population due to behavioral reason ...
... evidence, they point to populations of mosquitoes, salmon and other creatures that no longer interbreed with their main populations.50,51 However, these are examples of reproductive isolation-as subpopulations get isolated they often won't interbreed with the main population due to behavioral reason ...
Speciation of Heavy Metals and Radioisotopes
... The term “heavy metal” actually refers to stable metals of density greater than around 5 to 6 g cm-3, although they are now often regarded as those discharged as by-products of industrial operations. These include cadmium, copper, lead, mercury, nickel, zinc and the metalloid arsenic and find their ...
... The term “heavy metal” actually refers to stable metals of density greater than around 5 to 6 g cm-3, although they are now often regarded as those discharged as by-products of industrial operations. These include cadmium, copper, lead, mercury, nickel, zinc and the metalloid arsenic and find their ...
Mate-recognition and species boundaries in the ascomycetes
... that a conversion to self-fertility or asexuality reduces gene flow between individuals of the same population just as much as between two different populations. In the extreme circumstance, a completely selfing or asexual species, each individual will give rise to a genetically isolated lineage or ...
... that a conversion to self-fertility or asexuality reduces gene flow between individuals of the same population just as much as between two different populations. In the extreme circumstance, a completely selfing or asexual species, each individual will give rise to a genetically isolated lineage or ...
What is a population? Review of Genetics Terminology
... 4. Behavioral isolation – little or no sexual attraction between males and females 5. Mechanical isolation – anatomical differences prevent exchange of gametes 6. Gametic isolation – female and male gametes fail to unite in fertilization ...
... 4. Behavioral isolation – little or no sexual attraction between males and females 5. Mechanical isolation – anatomical differences prevent exchange of gametes 6. Gametic isolation – female and male gametes fail to unite in fertilization ...
DNC 2013
... needs. In all cases, adaptation aims at finding strategies to better deal with the surrounding environment [1]. Natural selection through fitness landscapes or geographic barriers are good examples how global influences are considered when modeling adaptation in an evolutionary process. On the other ...
... needs. In all cases, adaptation aims at finding strategies to better deal with the surrounding environment [1]. Natural selection through fitness landscapes or geographic barriers are good examples how global influences are considered when modeling adaptation in an evolutionary process. On the other ...
evolution_v_creation..
... In recent years, scientists also have documented evolution of a new species of marine worm, called a polychate. And among plants, a least a dozen new species have been seen to arise over the last 50 years, including a new species of corn. ...
... In recent years, scientists also have documented evolution of a new species of marine worm, called a polychate. And among plants, a least a dozen new species have been seen to arise over the last 50 years, including a new species of corn. ...
File
... changes in salinity / changes in ocean currents change distribution of nutrients; changes in predator-prey relationships (due to ecosystem disruption); increased success of pest species; temperate species with bigger range of habitats as ice melts; increased rate of decomposition of detritus; ...
... changes in salinity / changes in ocean currents change distribution of nutrients; changes in predator-prey relationships (due to ecosystem disruption); increased success of pest species; temperate species with bigger range of habitats as ice melts; increased rate of decomposition of detritus; ...
Here - Fred Hutchinson Cancer Research Center
... 1Z4, Canada. Fax: 604 822 2416; E-mail: [email protected] © 2006 Blackwell Publishing Ltd ...
... 1Z4, Canada. Fax: 604 822 2416; E-mail: [email protected] © 2006 Blackwell Publishing Ltd ...
11 | EVOLUTION AND ITS PROCESSES
... Genetic diversity in a population comes from two main sources: mutation and sexual reproduction. Mutation, a change in DNA, is the ultimate source of new alleles or new genetic variation in any population. An individual that has a mutated gene might have a different trait than other individuals in t ...
... Genetic diversity in a population comes from two main sources: mutation and sexual reproduction. Mutation, a change in DNA, is the ultimate source of new alleles or new genetic variation in any population. An individual that has a mutated gene might have a different trait than other individuals in t ...
concepts-of-biology
... species change had been suggested and debated well before Darwin. The view that species were static and unchanging was grounded in the writings of Plato, yet there were also ancient Greeks that expressed evolutionary ideas. In the eighteenth century, ideas about the evolution of animals were reintro ...
... species change had been suggested and debated well before Darwin. The view that species were static and unchanging was grounded in the writings of Plato, yet there were also ancient Greeks that expressed evolutionary ideas. In the eighteenth century, ideas about the evolution of animals were reintro ...
Sympatric speciation
Sympatric speciation is the process through which new species evolve from a single ancestral species while inhabiting the same geographic region. In evolutionary biology and biogeography, sympatric and sympatry are terms referring to organisms whose ranges overlap or are even identical, so that they occur together at least in some places. If these organisms are closely related (e.g. sister species), such a distribution may be the result of sympatric speciation. Etymologically, sympatry is derived from the Greek roots συν (""together"", ""with"") and πατρίς (""homeland"" or ""fatherland""). The term was invented by Poulton in 1904, who explains the derivation.Sympatric speciation is one of three traditional geographic categories for the phenomenon of speciation. Allopatric speciation is the evolution of geographically isolated populations into distinct species. In this case, divergence is facilitated by the absence of gene flow, which tends to keep populations genetically similar. Parapatric speciation is the evolution of geographically adjacent populations into distinct species. In this case, divergence occurs despite limited interbreeding where the two diverging groups come into contact. In sympatric speciation, there is no geographic constraint to interbreeding. These categories are special cases of a continuum from zero (sympatric) to complete (allopatric) spatial segregation of diverging groups.In multicellular eukaryotic organisms, sympatric speciation is thought to be an uncommon but plausible process by which genetic divergence (through reproductive isolation) of various populations from a single parent species and inhabiting the same geographic region leads to the creation of new species.In bacteria, however, the analogous process (defined as ""the origin of new bacterial species that occupy definable ecological niches"") might be more common because bacteria are less constrained by the homogenizing effects of sexual reproduction and prone to comparatively dramatic and rapid genetic change through horizontal gene transfer.