User:Relavoie/sandbox

Haplotype convergence is the unrelated appearance of identical haplotypes in separate populations, through either convergent evolution or random chance.

Haplotype convergence is more common in more closely related sequences, as the amount of changes required to produce identical sequences in two different organisms decreases with increased relatedness. Substitution bias further increases the likelihood of haplotype convergence, as this increases the probability of mutations occurring at the same site. Sequences may also diverge from the same original sequence and then revert, converging in this manner. Convergence through convergent evolution in two unrelated groups is much less common, as derived traits may arise through dramatically different pathways. This convergence may cause issues in various phylogenetic analyses, leading the researcher to believe the groups being studied are identical, when in fact they may be highly divergent in their evolutionary history. This has been recorded in various haplotypes of the Y chromosome in humans, causing issues with determining the ancestries of certain groups. These phylogenetic issues can mostly be resolved through analysis of a different gene or genes, or more recently, whole genome sequencing.

Haplotype convergence is a term used in the study of DNA haplotypes (series of closely related genetic markers) for two haplotypes resembling each other due to chance.

Description[edit]
Similarities between different haplotypes can result from mutations; within these mutations, identity strictly by state can occur causing two chance haplotypes to look identical. Two haplotypes may contain similar markers for two different reasons: common ancestry or coincidence; the latter is called haplotype convergence. By coincidence, random mutations over sufficient time can result in the same or similar markers being present in two haplotypes, as the markers randomly change. Coincidence becomes less likely if more markers are tested, since that would require a larger amount of rare coincidences. While convergent evolution results from multiple of factors, haplotype convergence is a type of convergent evolution resulting from random mutation over time.

Examples[edit]
A modern study observed that when threespine stickleback were introduced to an environment similar to that of the ancient bluefin killifish and black bream, they evolved the same genetic changes independently, promoting color vision.

In a different example of haplotype convergence, a study of New World mitochondrial DNA haplogroups observed that the similarities in haplotypes between Native Americans and Asians were a result of the hypervariability of the HVSI region in mitochondrial DNA, rather than common ancestry.

References[edit]

 * 1) Jump up^
 * 2) ^ Jump up to:a b
 * 3) Jump up^ [better source needed]
 * 4) Jump up^
 * 5) Jump up^ Marques, David A.; Taylor, John S.; Jones, Felicity C.; Palma, Federica Di; Kingsley, David M.; Reimchen, Thomas E. (2017-04-11). "Convergent evolution of SWS2 opsin facilitates adaptive radiation of threespine stickleback into different light environments". PLOS Biology. 15 (4): e2001627. doi:10.1371/journal.pbio.2001627. ISSN 1545-7885.