title: Phylogenetic inconsistency caused by ancient sex-biased gene migration.
abstract: Inferences of ancient sex-biased migration patterns using sex-linked genetic markers are usually difficult because of a stochastic process of allele fixation. Nevertheless, incongruent phylogenetic trees between different sex-linked markers and between sex-linked and autosomal markers are frequently interpreted as a signature of sex-biased migration without further statistical evaluation. I investigated the types of incongruent phylogenetic trees from which past sex-biased migration events can be statistically supported under the coalescent model. In the case of mammals, detecting a sex-biased migration pattern is not guaranteed by comparing the phylogenetic pattern of mitochondrial and Y-chromosomal loci. Likewise, evidence of introgression at a mitochondrial locus, but not at autosomal loci, does not support the hypothesis of an ancient female-biased migration pattern with statistical significance. In contrast, evidence of introgression at ≥ 5 unlinked autosomal loci, but not at a Y-chromosomal locus, would reject the null hypothesis of a sexually equal migration rate with statistical significance. A similar argument can be made to infer a male-biased migration pattern. Furthermore, the investigation of many recombining sex-biased markers such as X-chromosomal loci in mammals has the potential to efficiently detect ancient sex-biased demographic patterns.
authors: Department of Population Genetics, National Institute of Genetics, Mishima, Japan. nosada@lab.nig.ac.jp
authors: Naoki
authors: N
authors: Osada
mesh_terms: D000818:Animals; D005260:Female; D051456:Gene Flow / Q000235:genetics*; D056426:Genetic Loci / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D008297:Male; D008957:Models, Genetic; D010802:Phylogeny; D011336:Probability; D012727:Sex Characteristics
chemical_list: D005819:Genetic Markers