Good. You didn’t think for a moment that I would write about Kentucky Derby decisions, disqualifications and all. Of course I won’t. Don’t know the rules of that sport, or any sport for that matter.

Instead I am praising science, once again, which has produced some fascinating new insights into the domestication of horses, a feat that revolutionized transport and warfare. You can read about the details here but here are the highlights:

Create an interdisciplinary team of 120(!) geneticists, evolutionary biologists and archeologists and let them figure out how 5500 years ago the horse became servant to (wo)man. Have them generate DNA data from 278 equine subfossils with ages mostly spanning the last six millennia.

Find out this way that in addition to the known two lines, domestic and Przewalski’s horses, there were two more, found on the Iberian Peninsula and in Siberia, now extinct.

Of special interest for these scientists was the fact that selective breeding shaping the look and functions of the horse started about 3000 years ago, most likely in Persia. Making them slimmer and stronger increased the mobility and speed of horses. Europeans picked up on this, and within a few hundred years they influenced the horse genome in more ways than through the previous 4000 years of domestication.

There is still uncertainty where the very first human horse interaction took place, despite all we know about horses. The traditional presumption that it happened in the steppes of Kasachstan was undermined by this current study. The most likely places under discussion are now Anatolia, the Pontic-Caspian steppes in Eurasia or the Middle East. Take your pick.

DNA analysis was also able to establish the recent impact of humans by means of diversity management, selection and hybridization of horses. What they found was not all good:

Most strikingly, we found that while past horse breeders maintained diverse genetic resources for millennia after they first domesticated the horse, this diversity dropped by ∼16% within the last 200 years. This illustrates the massive impact of modern breeding and demonstrates that the history of domestic animals cannot be fully understood without harnessing ancient DNA data. Importantly, recent breeding strategies have also limited the efficacy of negative selection and led to the accumulation of deleterious variants within the genome of horses. This illustrates the genomic cost of modern breeding. Future work should focus on testing how much recent progress in veterinary medicine and the improving animal welfare have contributed to limit the fitness impact of deleterious variants.

And while we are on the topic of DNA analysis, here is something to ponder about what the results of genetic testing in humans can or do tell us: misconceptions abound.

And if instead of experimental science you want some clinical psychology on this Wednesday morning, read this about psychics and the (hurt) feelings of horses.

You tell me if it makes horse sense.

Photographs today are of horse sculptures made by Steve Tilden and some of my pastiches using more of his work in the style of different painters.

Music from two very different sources: