Comment by mirimir | Hacker News Reader

Comment by mirimir | Hacker News Reader

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> In fact, a screening for single-nucleotide polymorphisms (SNPs) in 14.3 kb of noncoding Y chromosome sequence among 52 male horses of 15 different breeds did not identify a single segregation site.

That's just part of the Y chromosome.

But this is a better cite:

> We used high throughput sequencing technology to identify the first polymorphic Y-chromosomal markers useful for tracing paternal lines. The nucleotide variability of the modern horse Y chromosome is extremely low, resulting in six haplotypes (HT), all clearly distinct from the Przewalski horse (E. przewalskii). The most widespread HT1 is ancestral and the other five haplotypes apparently arose on the background of HT1 by mutation or gene conversion after domestication.

Wallner et al. (2013) Identification of Genetic Variation on the Horse Y Chromosome and the Tracing of Male Founder Lineages in Modern Breeds

http://journals.plos.org/plosone/article?id=10.1371/journal....

So yes, it seems that all domestic stallions descend from just one ancestor stallion. That's amazing!

> So yes, it seems that all domestic stallions descend from just one ancestor stallion. That's amazing!

I once a class on population genetics in which the instructor commented that the "mitochondrial Eve" idea is kind of over-played. Basically, if you look at any genetic locus, you're going to find some most-recent common ancestor, but that most-recent common ancestor isn't going to be the same for all loci. (So yes, there might be a "mitochrondrial Eve", but there's also a "cytochrome Sam" and they're not necessarily the same person.)

https://en.wikipedia.org/wiki/Coalescent_theory

"""Because of recombination, different gene loci follow different pathways of ancestry, resulting in different gene genealogies. The coalescent is also relevant to phylogenetics, as incomplete lineage sorting between speciation events results in conflict among gene-loci in phylogenetic relationships inferred among species."""

(I'm no expert, but sometimes I think population genetics has one of the most interesting mathematical structures of all the natural processes I know about.)

I was about to write that Y chromosomes don't recombine. But then I checked:

> The Y chromosome is only one-third the size of the X. Although the Y has a partner in X, only the tips of these chromosomes are able to recombine.

http://www.hhmi.org/biointeractive/evolution-y-chromosome

But still, Wallner et al. (2013) only found six versions of the Y chromosome in modern horses, and argued that five of them "apparently arose on the background of HT1 by mutation or gene conversion after domestication".

So yes, it looks like one ancestral stallion. But then, all commercial bananas are clones.

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