‘The first horse genome reference sequence was released in 2009. A decade later, the horse represents the domestic animal with the largest number of ancient genomes sequenced. This resource has not only already helped rewrite important parts of the complex population history underlying horse domestication, but also opened many areas for future research.‘
This quote is from an article published in 2019, so the info should not be a surprise to anyone interested in horses. I would like to add the wild and free-roaming horse population of the USA to the following caution from the authors:
… the domestic horse has been significantly reshaped during the last millennium and experienced a sharp decline in genetic diversity within the last two centuries. At a time when no truly wild horses exist any longer, this calls for enhanced conservation in all endangered populations. These include the Przewalski’s horse native to Mongolia, and the many local breeds side‐lined by the modern agenda, but yet representing the living heritage of over five millennia of horse breeding.
We have a priceless genetic resource in our wild horses, especially those of Iberian and Barb descent, and we should manage them as a national treasure not as pests.
“This suggests that the genomic signature left by the domestication bottleneck was mild, and relative to that observed in some modern breeds. This mild bottleneck is consistent with the large mitochondrial diversity found in horses, which was interpreted as a pervasive restocking of wild mares during the initial spread of horse husbandry.”
Interpretation:Even IF none of the wild horse lines in North America 5000 years ago (as shown by recent sedaDNA studies) survived through until 500 years ago… We know can tell that the “new” lines of Equus caballus introduced by the Spanish were actually GENETICALLY SIMILAR to the original endemic lines.“