A Genetic Finding Suggests Mutation to Make Horses More Rideable

        The modern domestication of horses can be dated back to over 4,200 years ago. A team of scientists, led by molecular archaeologist Ludovic Orlando, observed the genomes of ancient horses and compared them to ones of the domesticated horses humans are familiar with today. Whilst studying the genomes, nine specific genes stood out as selected and targeted by human breeders   

 

        One gene recorded was ZFPM1, a gene familiar to scientists as the marker for anxiety levels in mice and human well being. This was one of the first genes selected by breeders around 5,000 years ago, suggesting the original concern for domestication was keeping the horse tamer.

        Interestingly enough, around 300-800 years later, the breeders advanced their selection and the gene Gasdermin C (GSDMC) strongly started to appear. In humans, a mutation of this gene causes chronic back pain and disorders such as spinal stenosis. In horses, it is seen to be related to the body length to body height ratio. 

        Once Orlando and his team discovered horses with this gene mutation when first appearing had 20% more offspring than those without, they ran testing on mice and inactivated their GSDMC genes. This experiment found the mice's spines modified to become straighter and forelimbs to be stronger.

        Orlando concludes "people intended to put that variant more frequently into the population... when you see something like that, you know you're onto something that was a real game changer for horse biology".

        The research done by Orlando and his colleagues is impressive and presents the importance of to be able to fully understand the human selected genes of any animal, in this case horses, it must be compared to the original non-domesticated ancestor. Learning more about the genetic makeup of one of the first animals domesticated by humans can help us further learn about the scientific thought process of our ancestors. 

Sources:

https://www.sciencenews.org/article/tamed-horses-rideable-genetic-mutation 

https://www.ncbi.nlm.nih.gov/gene?Db=gene&Cmd=DetailsSearch&Term=56169 

                   

Feline genetics help pinpoint first-ever domestication of cats

 A study at the university of Missouri has determined how long ago cats were domesticated. Leslie Lyons, a feline geneticist, has studied about 200 gene markers in cats from around the world to help pinpoint this domestication. One of these gene markers was microsatellites, which are quickly mutating. 

For a lot of other domesticated species, it seems that they have had multiple domestication events over the years, while cats seem to have been domesticated once, about 10,000 years ago, as humans began to migrate. When humans began to migrate, it seems they felt the need to bring cats with them, which I can't blame them for. 

Cats are also referred to as "semi domesticated" because although cats do well in human care, if they were let outside on their own, they could fend for themselves and hunt just fine. 

https://www.sciencedaily.com/releases/2022/12/221205121616.htm

Donkey DNA Reveals Domestication Origin

Researchers have been analyzing the DNA of donkeys to trace the origin of domestication in the species. Donkeys have long been used by humans throughout history and today can be found all over the world, but the question of where donkeys were first domesticated remained unanswered. Asia or Africa has been believed to be their ancestorial homeland, but the exact location was unknown. The head of the current study, molecular archaeologist Ludovic Orlando, attributed the ambiguity to not having a large enough sample size of donkeys from different areas of the world to draw a conclusion. Orlando's study addressed this by gathering genetic data of donkeys from 31 countries worldwide. In total the team sequenced 207 genomes including that of 31 donkeys living 100-4000 years ago. By comparing the genetic information in the DNA Orlando's team was able to trace back domestication to a single event occurring in East Africa 7000 years ago. From this initial domestication in the Horn of Africa, donkeys spread to elsewhere and formed genetically distinct groups. The timing of the domestication in 5000BCE corresponds with the widening of the Sahara desert so its possible donkeys were domesticated to help with moving goods across the arid climate. 

Donkeys have played a vital role to humans throughout history and are still used by many low-middle income countries today. Knowing the origins of donkeys and their domestication can provide us with more insight into how these creatures function and the traits they have evolved to make them so good at the work we need them for like field work and moving goods. I am grateful for the work Orlando and his colleagues have done to answer this question of donkey domestication origin. I hope this model of sampling genomes from individuals of a species from all over the world, can be applied elsewhere for researchers looking to learn more about other species and trace back other domestication events.