The paper will mainly focus on three point: how Y chromosome originated; the function …show more content…
2009); the same study also found that in Drosophila pseudoobscura the Y chromosome had a large portion of itself that was not homologous as the X chromosome. All these evidences suggest that the Drosophila Y chromosome has an alternative origin than the mammalian Y …show more content…
The Y chromosome also has several microsatellite sequences on it, what makes these microsatellite sequences special is that these sequences locate on the non-recombining region, meaning that they are likely to be preserved along the time. Therefore, it is possible to use these microsatellite sequences to generate a phylogenetic tree for Y chromosome, and researchers did that in 2002: by using the polymorphism mutations exist in the non-recombining region of Y chromosome, the researchers made a phylogenetic tree for 153 Y chromosome haplogroups, which helps other researchers to further study the Y chromosome evolution (Y Chromosome Consortium 2002). Then in 2003 researchers used the generated phylogenetic tree to construct a map that showed the distribution of different Y chromosome haplogroups around the world (Jobling & Tyler-Smith 2003). In 2013 by studying the human Y chromosome, researchers have found a human Y chromosome that presented the ancestral states for all the polymorphism sites, which meant that it was the ancestor of all the known human Y chromosome (Mendez et al. 2013); this finding suggests that the now known most recent common ancestor of human Y chromosome existed about 338 thousand years