Hybrid speciation

Hybrid speciation is the process wherein hybridization between two different closely related species

Species

In biology, a species is:* a taxonomic rank or* a unit at that rank ....

 leads to a distinct phenotype

Phenotype

A phenotype is any observable characteristic or trait of an organism: such as its morphology, development, biochemical or physiological properties, or behavior. Phenotypes result from the expression of an organism's genes as well as the influence of environmental factors and possible interactions...

. This phenotype in very rare cases can also be fitter than the parental lineage and as such natural selection

Natural selection

Natural selection is the process by which heritable traits that make it more likely for an organism to survive and successfully reproduce become more common in a population over successive generations...

 may then favor these individuals. Eventually, if reproductive isolation

Reproductive isolation

An important concept in evolutionary biology, reproductive isolation is a category of mechanisms that prevent two or more populations from exchanging genes. The separation of the gene pools of populations, under some conditions, can lead to the genesis of distinct species...

 is achieved, it may lead to a separate species. However, reproductive isolation between hybrids and their parents is particularly difficult to achieve and thus hybrid speciation

Speciation

Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages...

 is considered an extremely rare event.

Hybridization without change in chromosome

Chromosome

A chromosome is an organized structure of DNA and protein that is found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions...

 number is called homoploid hybrid speciation.

Hybrid speciation is the process wherein hybridization between two different closely related species

Species

In biology, a species is:* a taxonomic rank or* a unit at that rank ....

 leads to a distinct phenotype

Phenotype

A phenotype is any observable characteristic or trait of an organism: such as its morphology, development, biochemical or physiological properties, or behavior. Phenotypes result from the expression of an organism's genes as well as the influence of environmental factors and possible interactions...

. This phenotype in very rare cases can also be fitter than the parental lineage and as such natural selection

Natural selection

Natural selection is the process by which heritable traits that make it more likely for an organism to survive and successfully reproduce become more common in a population over successive generations...

 may then favor these individuals. Eventually, if reproductive isolation

Reproductive isolation

An important concept in evolutionary biology, reproductive isolation is a category of mechanisms that prevent two or more populations from exchanging genes. The separation of the gene pools of populations, under some conditions, can lead to the genesis of distinct species...

 is achieved, it may lead to a separate species. However, reproductive isolation between hybrids and their parents is particularly difficult to achieve and thus hybrid speciation

Speciation

Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages...

 is considered an extremely rare event.

Hybridization without change in chromosome

Chromosome

A chromosome is an organized structure of DNA and protein that is found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions...

 number is called homoploid hybrid speciation. It is considered very rare but has been shown in Heliconius

Heliconius

Heliconius comprise a colorful and widespread brush-footed butterfly genus distributed throughout the tropical and subtropical regions of the New World. These butterflies utilize Passion flower plants as their larval food source and rely on bright wing color patterns to signal their distasteful to...

butterflies

Butterfly

A butterfly is an insect of the order Lepidoptera. Like all Lepidoptera, butterflies are notable for their unusual life cycle with a larval caterpillar stage, an inactive pupal stage, and a spectacular metamorphosis into a familiar and colourful winged adult form. Most species are day-flying so...

 and in sunflower

Sunflower

Sunflowers are annual plants native to the Americas, that possess a large inflorescence .-Description :...

s. Polyploid speciation, which involves changes in chromosome number, is a more common phenomenon, especially in plant species.