On 2015 Oct 11, Donald Forsdyke commented:

GC% – A COLLECTIVE VARIATION THAT FOSTERS SPECIATION

Among members of a species there is generally a mean genomic GC% value with a bell-curve distribution about this mean. The small group to the left of the mean are biased towards low GC%. The small group to the right of the mean are biased towards high GC%. These fringe groups can be said to have collectively varied away from the mean.

In keeping with the proposal that the reproductive isolation needed for speciation would be fostered by a collective variation (1), it has been shown how differences in GC% would impair recombination between a group on the fringe of the bell-curve and the main species group at the centre of the bell-curve (2). Other conditions being propitious (e.g. further rein is given to natural selection), a fringe group could then become a separate species with its own bell-curve GC% distribution.

Thus, if through reproductive isolation the low GC% group departed the main species, the population mean value would move slightly to the right (higher GC%). While Mugal and her colleagues (3) provide a valuable review of the literature on genomic base composition, the implications for speciation are not mentioned. For more please see my speciation text (4) and my bioinformatics textbook (5). There are also recent PubMed comments (6, 7).

(1) Romanes GJ (1886) Physiological selection: An additional suggestion on the origin of species. Journal of the Linnaean Society, Zoology 19, 337-411.

(2) Forsdyke DR (1996) Different biological species "broadcast" their DNAs at different (G+C)% "wavelengths". J. Theoret. Biol. 178, 405-417. Forsdyke DR, 1996% "wavelengths".")

(3) Mugal CF, Weber DD, Ellegren H (2015) GC-biased gene conversion links the recombination landscape and demography to genomic base composition. BioEssays 35: (in press) doi:10.1002/bies.201500058 Mugal CF, 2015

(4) Forsdyke DR (2001) The Origin of Species Revisited. McGill-Queen’s University Press, Montreal.

(5) Forsdyke DR (2011) Evolutionary Bioinformatics. 2nd edition. Springer, New York.

(6) Clément Y, Fustier M-A, Nabholz B, Glémin S. (2014) The bimodal distribution of genic GC content is ancestral to monocot species. Genome Biology and Evolution 7, 336-348. Clément Y, 2014

(7) Turner LM, Harr B (2014) Genome-wide mapping in a house mouse hybrid zone reveals hybrid sterility loci and Dobzhansky-Muller interactions. Elife Dec 9;3 doi: 10.7554/eLife.02504 Turner LM, 2014

On 2015 Oct 11, Donald Forsdyke commented:

GC% – A COLLECTIVE VARIATION THAT FOSTERS SPECIATION

Among members of a species there is generally a mean genomic GC% value with a bell-curve distribution about this mean. The small group to the left of the mean are biased towards low GC%. The small group to the right of the mean are biased towards high GC%. These fringe groups can be said to have collectively varied away from the mean.

In keeping with the proposal that the reproductive isolation needed for speciation would be fostered by a collective variation (1), it has been shown how differences in GC% would impair recombination between a group on the fringe of the bell-curve and the main species group at the centre of the bell-curve (2). Other conditions being propitious (e.g. further rein is given to natural selection), a fringe group could then become a separate species with its own bell-curve GC% distribution.

Thus, if through reproductive isolation the low GC% group departed the main species, the population mean value would move slightly to the right (higher GC%). While Mugal and her colleagues (3) provide a valuable review of the literature on genomic base composition, the implications for speciation are not mentioned. For more please see my speciation text (4) and my bioinformatics textbook (5). There are also recent PubMed comments (6, 7).

(1) Romanes GJ (1886) Physiological selection: An additional suggestion on the origin of species. Journal of the Linnaean Society, Zoology 19, 337-411.

(2) Forsdyke DR (1996) Different biological species "broadcast" their DNAs at different (G+C)% "wavelengths". J. Theoret. Biol. 178, 405-417. Forsdyke DR, 1996% "wavelengths".")

(3) Mugal CF, Weber DD, Ellegren H (2015) GC-biased gene conversion links the recombination landscape and demography to genomic base composition. BioEssays 35: (in press) doi:10.1002/bies.201500058 Mugal CF, 2015

(4) Forsdyke DR (2001) The Origin of Species Revisited. McGill-Queen’s University Press, Montreal.

(5) Forsdyke DR (2011) Evolutionary Bioinformatics. 2nd edition. Springer, New York.

(6) Clément Y, Fustier M-A, Nabholz B, Glémin S. (2014) The bimodal distribution of genic GC content is ancestral to monocot species. Genome Biology and Evolution 7, 336-348. Clément Y, 2014

(7) Turner LM, Harr B (2014) Genome-wide mapping in a house mouse hybrid zone reveals hybrid sterility loci and Dobzhansky-Muller interactions. Elife Dec 9;3 doi: 10.7554/eLife.02504 Turner LM, 2014