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Speciation via polyploidy: A diploid cell undergoes failed meiosis, producing diploid gametes, which self-fertilize to produce a tetraploid zygote. Polyploidy is frequent in plants, some estimates suggesting that 30–80% of living plant species are polyploid, and many lineages show evidence of ancient polyploidy (paleopolyploidy) in their genomes.
It is possible on rare occasions for ploidy to increase in the germline, which can result in polyploid offspring and ultimately polyploid species. This is an important evolutionary mechanism in both plants and animals and is known as a primary driver of speciation . [ 8 ]
It has been suggested that many polyploidization events created new species, via a gain of adaptive traits, or by sexual incompatibility with their diploid counterparts. An example would be the recent speciation of allopolyploid Spartina — S. anglica; the polyploid plant is so successful that it is listed as an invasive species in many ...
Polyploidy is pervasive in plants and some estimates suggest that 30–80% of living plant species are polyploid, and many lineages show evidence of ancient polyploidy (paleopolyploidy) in their genomes. [8] [9] [10] Huge explosions in angiosperm species diversity appear to have coincided with ancient genome duplications shared by many species.
Polyploid speciation, which involves changes in chromosome number, is a more common phenomenon, especially in plant species. Polyploidy is a mechanism that has caused many rapid speciation events in sympatry because offspring of, for example, tetraploid x diploid matings often result in triploid sterile progeny. [257]
The list of organisms by chromosome count describes ploidy or numbers of chromosomes in the cells of various plants, animals, protists, and other living organisms.This number, along with the visual appearance of the chromosome, is known as the karyotype, [1] [2] [3] and can be found by looking at the chromosomes through a microscope.
The new species lives in burrows with ghost shrimp, researchers said. Four-eyed creature — with ‘bright red’ body — found burrowed in sand. See new species
Polyploid (tetraploid)? Richards, 1990: Recent work shows this may not be of hybrid origin (Nazre, 2014) Gossypium hirsutum: Upland cotton: Malvaceae: hybrid origin: Confirmed: Uncertain, referred to as 'A' and 'D' Polyploid (formed <1MYA) 2n =4x=52: Wendel and Cronn 2003: Polyploidization likely led to agronomically significant traits ...