Close karyological kinship between the reptilian suborder Serpentes and the class Aves. Such groups include monotremes, Drosophilasome other insects, some fish, some reptiles, and some plants. Degeneration may simply be the fate of all non-recombining sex chromosomes, due to three common evolutionary forces: high mutation rateinefficient selectionand genetic drift.
Mittwoch U. This human sex chromosome evolution in Wigan particularly interesting in the context of sex chromosome evolution, since the model did not assume any epistasis or cost of adaptation to a specific environment i.
In other words, since the Y chromosome is single, it has duplicates of its genes on itself instead of having a second, homologous, chromosome. A second observation is that although many of the processes involved in sex chromosome differentiation are similar to those discussed in the speciation literature inversions, mutation accumulation, chromosomal rearrangements, etc.
The P. Otto, Human sex chromosome evolution in Wigan. There are different W chromosomes in the population: a with an advantageous mutationb and c with neutral mutations. G3 Bethesda 9— For example, neo-sex chromosomes can also evolve in situations where a sex chromosome pair already exists, either by fusion to an autosome or by acquisition of a new sex-determining factor on an autosome, both leading to sex chromosome turnover Natarajan, S.
The care, maintenance, and treatment of the animals used in this study followed protocols approved by the University Institutional Animal Care and Use protocol R Supplementary Dataset 7.
Rights and permissions Reprints and Permissions. Such groups include monotremes, Drosophila , some other insects, some fish, some reptiles, and some plants. Sex determination: why so many ways of doing it?