Failure of selective breeding?

Mugabe asserts at pumpkinperson:

off topic but a huge “teachable moment” today for hereditists.

for the first time since affirmed in ’78 a horse has won the tiple crown.

what horse still holds the record times in all three triple crown races?

secretariat in ’73.

the lesson is that despite enormous incentive to breed a super horse none have succeeded in besting secretariat. and that’s been ca 14 generations of thoroughbreds since ’73.

While Mugabe's broader point is without merit (there's no shortage of examples of successful applications of selective breeding to animals), it does look like thoroughbred breeders may be doing it wrong. Steve Sailer noted in 2005:

Enormous amounts of money are spent to acquire the best breeding stock for thoroughbred horse racing. The average time of the winning horse in the Kentucky Derby dropped steadily up through middle of the 20th Century (as shown in the red line above), yet there has been virtually no overall improvement in average time since 1950 (as shown in the blue line). If the improvements seen from 1896-1949 had continued, the average winning time today would be about three seconds faster.

Expert ratings seem to point to a similar conclusion:
The trend line (red curve) now shows a clear dip between about 1940 and 1970. This means that a larger number of higher ranked horses are clustered in that time frame. The upward trend since then reinforces the position of the critics in that the horses on the list selected since mid-century are, as a group, not as highly regarded as those that came immediately before them. The overall pattern seems to have been continual improvement through the first half of the 20th century followed by a gradual decline since then. This study is far from definitive because the rankings are objective only to the extent that humans apply their best judgment. On the other hand, since there is no purely objective standard to use, the opinions of the seven experts are as a good as any and better than most. The result of their judgment is that changes have occurred and that the best of recent years are not quite up to the level of the best that preceded them.
In contrast, standardbred harness racing times have continued to decline:

From the above chart, starting in 1930 standardbreds have improved winning Hambo times by 7.9%, while thoroughbreds of the same period have improved Derby winning times by just 1.8%. If you start analyzing the data at the time of the breaking of the magic 2:00 threshold the differences are even more striking – 7.0% for trotters vs. an imperceptible 0.08% for thoroughbreds.

The horse trainer quoted above thinks this difference mostly comes down to thoroughbred trainers not having "a very good grasp of equine exercise physiology". But assuming it's a matter of breeding, here's one major difference:
in order for the resulting foal to be registered with The Jockey Club, Thoroughbred breeders must have their mares bred by live cover. As inconvenient as this might seem to those unfamiliar with the Thoroughbred industry, this policy ensures the ability of more colts to end up at stud. If Thoroughbred mare owners weren't restricted by geography and location, they would no doubt be interested only in the sperm of the best of the best, thereby devaluing the stud services of all other stallions. In fact this is the case in the Standardbred industry. Because artificial insemination is the norm, the breed has improved much faster in comparison to the Thoroughbred. However, the Standardbred colt owner must make a profit at the racetrack because unless the colt is literally the best of the best there is no chance of making a profit on the colt as a stud (1).
There's also the question of what's actually being selected for.

"They're the ones who created this tragedy," Parker said. "Robert Clay is smart enough to know better. He bred her. That's where it starts. You don't blame the trainer, who does not have the reputation of breaking horses down, and you don't blame the poor little jockey. ... She was inbred three times to Raise a Native! [She broke down] right where Raise a Native was the weakest, right in the ankles, and everybody acts like they don't know what caused this filly to break down. It's written right there for everyone to see! Except they refuse to see it. To admit it is to address the fact that all these stallions that are bred like that, that all the yearlings that are bred like that, are potential accidents waiting to happen. And they've got so much money wrapped up in this crap!" [. . .]

Through the first 60 years of the 20th century, most of the major stallions and many of the best mares were owned and controlled by some of the oldest families and richest sporting patrons in America, by the Whitneys and Woodwards, the Bradleys and Wideners, the Klebergs and Mellons. They bred horses to race them, not to sell them, and they did so in order to compete against one other -- to beat their fellow members of The Jockey Club, to see who had the fastest horse. A cardinal article of their faith was to "improve the breed," which meant to breed a horse with great speed, stamina and soundness. In fact, on the C.V. Whitney farm in Lexington, a foal born with a crooked leg was usually taken into the woods and shot, lest he or she pollute the Whitney bloodlines with this inherent deformity.

By the middle of the last century, this tight-knit racing world began to change. As these families died out and their blue-chip breeding stock was sold at dispersal auctions, the best stallions and mares fell into the hands of commercial breeders, whose central motivation was to breed, not so much a sound or durable horse, but rather an attractive horse, a "cosmetic horse," who showed well, who had a pedigree filled with fashionable names, preferably sire lines that glowed with speed, and who thus would draw the biggest price at the fanciest yearlings sales. Because they needed to look like show horses, these hothouse yearlings were often raised in small pens and not allowed to run free, or to kick, bite and roughhouse with their peers.

[. . .] This gradual softening and weakening of the breed has led to the use of more medications to keep these horses running sound, among them the corticosteroids injected into injured knees and ankles. [. . .] Drugs are only one way that the industry has been trying to make up for the weakening of the American thoroughbred. A number of racetracks have already replaced their dirt tracks with softer Polytrack surfaces, for the purpose of reducing breakdowns, but all we know about these tracks is that they often are the bane of true speed horses, favoring come-from-behind plodders. They have made the outcome of races so unpredictable that they have driven the high-rolling, sophisticated gamblers away from the betting parlors; and they may or may not save horses' lives. The jury remains sequestered.

All such expedients are aimed at forgiving commercial breeders for what they have done to the breed. At the core of the problem is the fact that the fastest and most popular sire lines in the world are the least durable and sound.

[Eight Belles' breakdown: a predictable tragedy]

This decrease in starts per horse over time also sheds light on another contemptible fact directly related to the absurdity of the economic covetousness of the industry. With exaggerated breeding fees and bloodstock sales that generate literally millions of dollars it has forced breeders to resort to breeding something fashionable that people will be interested in buying. Unfortunately the fastest sires are usually the most unsound. In the commercial sense of the word, horses are no longer bred to race but rather are bred to sell.

[HORSE RACING — BREEDING FOR TROUBLE]

12 comments:

gcochran said...


Likely they've come pretty close to exhausting the genetic variation in thoroughbreds.

n/a said...

Greg,

I doubt that could be the entire explanation. Thoroughbreds are inbred, but they're not that inbred. And selection may have been intense, but I don't think it's been anything like systematic or intense enough for long enough (across the entire breed) that useful variation could be exhausted. With a longer term and more scientific approach, I'm sure race times could go significantly lower.


A Sequence Polymorphism in MSTN Predicts Sprinting Ability and Racing Stamina in Thoroughbred Horses
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0008645

Genome Sequence, Comparative Analysis, and Population Genetics of the Domestic Horse
http://www.sciencemag.org/content/326/5954/865

A Genome Scan for Positive Selection in Thoroughbred Horses [a few highly selected, very low heterozygosity sites are identified here, but I expect that as with most quantitative traits large numbers of small effect size variants probably combine to account for most heritable variation in racing ability]
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0005767

A High Density SNP Array for the Domestic Horse and Extant Perissodactyla: Utility for Association Mapping, Genetic Diversity, and Phylogeny Studies ["Mean individual inbreeding coefficients (F) were highest in the Thoroughbred and Standardbred (0.15 and 0.12, respectively), and lowest in the Hanoverian, Quarter Horse and Mongolian (0.06, 0.04, and 0.02, respectively)"; "The overall MAF across all breeds was 0.236 (SD = 0.139), and the median MAF was 0.224. The Mongolian breed displayed the highest genetic diversity, HE = 0.292, whereas genetic diversity was the lowest in the Thoroughbred HE = 0.247"]
http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1002451

Genome-Wide Analysis Reveals Selection for Important Traits in Domestic Horse Breeds
http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1003211

Genetic Diversity in the Modern Horse Illustrated from Genome-Wide SNP Data
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0054997

Bleeding lungs

However, the analysis of thoroughbred genetics is also revealing the other side of the coin, notes Matthew Binns of the Royal Veterinary College in London, UK. Many negative traits are associated with inbreeding in the diminutive gene pool, he says. "The selections we've made for fantastic beasts have had some detrimental consequences."

One tenth of thoroughbreds suffer orthopaedic problems and fractures, 10% have low fertility, 5% have abnormally small hearts and the majority suffer bleeding in the lungs, says Binns.

But as well as allowing breeders to select for performance-related genes, elucidating the horse genome may allow researchers to breed out negative traits, he says.

"Now we have a good amount of the horse genome, there are interesting times ahead," says Binns. "Over the next 10 years there will be some changes in this very traditional industry."
http://www.newscientist.com/article/dn7941


Anonymous said...

the broader point you ascribe to me, you never describe.

the toos very much still exist. how could they not?

your reading comprehension is even worse than Half Sigma's.

you're a moron and a liar.

Anonymous said...

http://www.forbes.com/families/list/#tab:overall

you'll still find many which originated before 1900.

great fortunes don't disappear. they are only dispersed, taxed, and dwarfed by more recent fortunes.

the duke of westminster is the richest british born british citizen. the most broadacred brit is the duke of sutherland.

n/a said...

Mugabe, my favorite self-diagnosed autistic,

"the broader point you ascribe to me, you never describe."

You asserted that "heredists" ought to draw a "lesson" from stagnation in Thoroughbred race times. Here is the substance of the rest of your comment (http://pumpkinperson.com/2015/06/06/iq-testosterone/comment-page-1/#comment-12902):

"that is, the hereditists may be disappointed when they find a ceiling and that the most eugenics can do is irradicate retardation and draw the population closer and closer to a not very high ceiling. [. . .]

btw, i very much am a eugenicist. i consider eugenics to be the most progressive policy. i just know that the results would not be even close to what heredistists think it would be."

On one side of the scale, we have hundreds/thousands of breeding experiments confirming predictions from quantitative genetics, including often extreme responses to selection. On the other side, we have Mugabe, who just knows "heredistists" are wrong, and selection for intelligence in humans could progress only towards some "not very high ceiling". For your comment to be remotely coherent we have to believe: (1) thoroughbreds don't already exceed their ancestors in selected traits by remarkable degrees (how does Mugabe quantify his "not very high ceiling") (2) stagnating thoroughbred race times in the face of a few decades of expensive but not overly scientific breeding outweighs the entire quantitative genetics literature and countless rather dramatic endpoints of plant and animal breeding.


"you'll still find many which originated before 1900."

Why don't you count them up for us.

Anonymous said...

self diagnosed autistic? when have i ever diagnosed myself as autistic? never.

autism, just like ADHD, is 99% bullshit. so by "self" you meant you?

U

R

A

JOKE!

and btw TEDIOUS fucktarded fucktard i'm a direct descendant of william bradford.

you are NOT!

Anonymous said...

there is the problem for hereditists.

THEY THEMSELVES ARE DUMB.

breed a better of secretariat fucktard.

DO

IT!

UNTIL

THEN

SHUT

UP.

you're just another castrato planging for mommy's tit.

here's my BGI e-mail fucktard:


Your Genome File: ---------- (4)
People
BGI Cognitive Genomics Lab
To
----------@----------.com
Mar 20
Hello Volunteer,


Genome ready.
Thank you for your interest in research into the genetics of intelligence. Though the project for which you’ve volunteered has been significantly delayed by obstacles to sequencing every volunteer for our study - obstacles which are not yet entirely behind us! - we’re pleased to announce that your genome is among the lucky ones, and now available for download at your convenience.


How is the research going?
Our processing of our volunteer DNA samples is taking significantly more time than expected, due in large part to unanticipated resource constraints upon our project, as BGI’s recent acquisition of Complete Genomics, sudden uncoupling from Illumina, and the subsequent shifting of all sequencing capacity into the new CG hardware platform has had a large impact on all of the BGI research projects, especially big ones like ours. This was compounded by a recent change in the local regulation of sequencing, which imposed a bottleneck on sequencing within BGI in general, though that has since been resolved. In consequence, upwards of half of our samples remain unsequenced at this time, and the delay affects all processing and resources available to us, as all samples are being shifted to the new BGI hardware platform, Complete Genomics.

Your HTML cannot be accepted: Must be at most 4,096 characters.

Sincerely,
BGI Cognitive Genomics Lab
Building No.11│Beishan Industrial Zone│Yantian District│Shenzhen 518083│China
认知基因组学 │ www.cog-genomics.org │contact@cog-genomics.org
ST-RM, BGI

get some class already.

Anonymous said...

and "my broader point"...what is it?

you still haven't said.

may be disappointed isn't the same as will be disappointed.

selective breeding has yet to produce a separate species.

so...maybe selective breeding over several million generations could turn a horse into a cheetah...maybe.

the bottom line of the balance sheet is:

you love black cock.

Anonymous said...

and the bottom line of the income statement is:

you love black cock.

ceiling?

think about it.

the price of bonds has a ceiling. the price of stocks doesn't. so which is it, stocks or bonds?

secretariat is a negative nominal rate on the long bond or 40 year JGBs.

fuck off!

Anonymous said...

and if you were conscientious you might've put a "[sic]" next to my "irradicate".

though it was really a "st.", as retardation once sufficiently separated from normal and no longer part of a continuous distribution is "irradicated".

but you missed it.

no golden ticket for you.

you're just an oompa loompa.

n/a said...

Mugabe,

You wrote some dumb shit. You were wrong. Deal with it.

You want to be a brilliant contrarian, but you're going to need to work harder on being brilliant. BGI email or no BGI email.

Blogger said...

+$3,624 profit last week!

Subscribe For 5 Star verified winning bets on NFL, NBA, MLB & NHL + Anti-Vegas Smart Money Signals...