‘Modern’ dog behavior already appeared in wolves

One of the largest studies ever done on dog genetics has revealed some of the foundations of the great diversification of breed behavior that exists today, including abilities such as herding, hunting or companionship.

According to research, although the vast majority of current dog breeds are recent, dating back only to the 19th century or even later, their capabilities were already present in much older lineages and, in many cases, depend on DNA variants that existed in wolves (ancestors of domesticated dogs) tens of thousands of years ago.

The conclusions have just been published in the scientific journal Cell, one of the most important in the world, by a trio of specialists in the USA. Emily Dutrow and Elaine Ostrander, from the National Institute for Research on the Human Genome, coordinated the work, which also included the participation of James Serpell, from the University of Pennsylvania.

To conduct the analysis, the three counted on genomic information from more than 4,000 dogs, among which there were both pedigree dogs and strays, “semiferal” individuals (basically dogs of domestic origin that live free and without an owner, a common phenomenon in places like India or Russia) and also species of wild canids, of which the most important for this type of study is the wolf (canis lupus🇧🇷

About a third of this data corresponds to the complete DNA of each dog, while the rest comprises maps of SNPs. The acronym designates single nucleotide polymorphisms, that is, exchanges of a single chemical “letter” of DNA.

Based on comparing these masses of data, the researchers were able to classify more than 200 dog breeds into ten major main lineages, which are not entirely isolated (since many breeds were created by crossing members of existing distinct breeds), but even so, they tend to have their own genetic characteristics.

The ten groups correspond, in general, to canine types that are well known to the public, such as different types of terriers, sheepdogs (including German shepherds) and retrievers (such as labradors and golden retrievers).

Going a step further, to try to assess the genetic influences behind the behavior of each canine lineage, the trio of scientists used a database of nearly 50,000 pedigreed dogs around the world. In it, the owners answer questionnaires about how their pets behave, which helped the authors of the research to correlate the genetic profiles of each breed with the temperament of the animals.

Thanks to the crossing of information, the scientists were able to identify several regions of the DNA that seem to have slightly different characteristics depending on the canine lineage.

“One of the most surprising findings was that many of the genomic changes that define major dog lineages can also be found in modern wolves,” Emily Dutrow said in a statement. “This indicates that humans have taken advantage of ancient variability among dogs’ wild ancestors to create unique dog types suited to performing specific tasks.”

A curious case is that of terriers —despite their modest size, 72% of their most typical genetic variants also appear in wolves. This is perhaps linked to the fact that they were originally developed as hunting dogs. In the case of retrievers, on the other hand, most of this variation appears to have arisen after domestication.

Another important detail is that the DNA variants do not directly interfere with the genes of the dogs, that is, with the “recipes” for the production of proteins in the organism. Instead, almost all of them seem to be in regulatory regions, which coordinate when and how a gene is turned on or off.