Historical notes on why something very tiny can change the world. VERY LONG
This is somewhat more limited, but… America developed its own version of the Thoroughbred. The majority of the progenitors of the American TB were from lines in the first UK General Stud Book of 1791(1781?), but a good number were not. These horses came in to the Colonies at the same time the British were creating the TB. So the roots are parallel and contemporaneous. There were some horses brought in from Spain and the Spanish colonies and quite a few dams of completely unknown lineage; in fact, all TBs start with horses of unknown lineage. But the horses imported to America by racing fans created not only the American TB but the Colonial Quarter Racing Horse, which then became the foundation of the Quarter Horse. Some other TBs were in the foundations of the Standardbred and the ASB.
In the beginning of TB racing, both here and in the UK, other than short track racing, horses ran at older ages and most racing was 4 mile heat racing. A horse had to win at least two 4 mile races in one day to be the winner overall. This was because racing to was improve the cavalry horse and not be an end in itself. Then the Brits in about 1820 started doing dashes–single races; and they started doing futurities for younger horses to prove breeding potential. Even today, geldings are not allowed to race in some of the British classics, consonant with the performance testing of the classic races. Futurities in those days mostly meant 3yos, BTW. The US didn’t leave heat racing until 40 or so years after the Brits. So the UK TB was being bred for specific traits–comparatively short speed (but not short track racing speed) over a mile to 2 1/2 miles from a completely closed population.
In the US, we have always had short track racing and bred for that; but we also bred for the stamina of the heat races. In the 1870’s we went to the British dashes, and a new wave of British importations of mares began. The old heat lines were sort of pushed aside, but not completely. We’d always imported TB sires. But in many of our mares the original Non-GSB mare lines were perpetuated, especially if they produced fast racers. Oddly enough, our population for organized racing was not completely closed until 1943; the JC maintained Appendix books for QH x TB crosses, IIRC, and also had an Appendix book for Arab crosses. All of the horses in those books, if bred to TBs, would have their descendants treated as any other American TB. And horses without JC pedigrees were allowed to race, and some became legends, like Pan Zareta.
This is getting to be a book, but allow me to continue.
Right before the turn of the 20th century, a few American horses were exported to the UK. Among these were Nearco’s third dam, Sibola and Lady Josephine’s damsire Americus, and Orby’s dam. Then a wave of US breeders relocated their operations to Europe in about 1900 because many states outlawed gambling on horses. The US breeders bred their American mares to European TB stallions and raced them and did well. Many of them located in France. Some of the results of the use of American mares were the Teddy son, Aethelstan, and the Ksar son, Tourbillon. The Brits in 1913 decided that any American TB who could not prove 100% descent from horses in the GSB would be treated as a NON-TB, allowed to race, but relegated to the Non-TB registry. Those horses who were from non-pure American lines but who had already bred UK descendants from pure UK TBs were grandfathered in. Exports in TBs went only one way, from Europe to North America, until the Pure Blood rule was modified just after WWII Now, of course, OUR JC has such a rule and non PURE horses are not even allowed to race.
What’s interesting is that all of these stallions whose genes have spread so very widely across the entire TB population in the 20th Century ALL have ancestresses who are from the UNKNOWN Colonial mares; and both Lady Josephine and Nearco have mares who descend from one of the Spanish imports–a mare named Croucher.
Why did I just go through all this? Because genetic recent research has showed that the spread of the C allele of the MSTN gene on Chromosome 18 came after the American TB entered the European population. The C was not not present in any of the historical stallions who had DNA analysis. It wasn’t in Eclipse; it wasn’t in Bend Or; it wasn’t in St. Simon; it wasn’t in Hyperion They tested 12 of the most famous historical UK stallions who were very widely used and whose body parts were preserved, and NONE of them carried the C allele. The European researchers say that Nearco was a “coalescing” point; and at the time he was breeding, so were the female descendants of Lady Josephine; and just a few years later, so was Tourbillon. The Euro researchers, who made a major error by premising their theory on a population limited to only GSB lines since the first GSB, say that they believe that where the C allele was all but absent in the historical population, it is now present in 51% of all TBs, in 70% of sprinting TBs, and in 90% of QHs. Where their incorrect premise could bite them badly is that they claim to have located the source of the C in a British native mare of the middle 1600’s. I’ve been told that the researchers believe that the C was in less than 9% of the breed founders. But it could just have easily come from one of the unknown Colonial mares, couldn’t it? Well, why not Croucher? Why couldn’t the C allele have been created or preserved in the American racing population and exported back to Europe at the turn of the 20th Century, then spread very widely with the descendants of Nearco, Lady Josephine and Tourbillon, as their descendants mated?
Point is that that one gene seems to make a major difference in what a TB is able to do and how it responds to training. One little gene, possibly from America and a non PURE mare, is in the process of swamping the entire population in less than 70 years.
Maybe there’s a gene like that in the Morgans, ASBs, etc, that would do just the same thing to the Euro WB where movement or jumping is involved if they were given a fighting chance.
