What relationship do dogs have with wolves?
Although the wolf and the dog have extremely similar DNA, at a morphological and behavioral level, the differences are notable.
For this reason many authors name Canis lupus familiaris as an independent species ( Canis familiaris )
When the wolf became a dog
When Charles Darwin studied morphological characters in domestic animals, he noted a number of differences compared to their wild relatives. This phenotypic manifestation of domestication is known as domestication syndrome .
The morphological changes produced in domestic animals are:
- smaller brain
- depigmentation
- Changes in the shape and size of the ears
- disturbed sexual cycles
- Changes in the concentration of hormones and neurotransmitters
Belyaev’s foxes
Studying Belyaev’s foxes in 1959, Raymond Coppinger proposed the hypothesis that associated with the character of submission and docility there would be a series of genes responsible for the morphological variations observed in dogs, that is, responsible for the domestication syndrome . These genes would have been selected by “accident” being visible in the offspring.
epigenetics
What is striking is that, as we have seen, this syndrome is common in all domestic species. The mystery of how such observable morphological changes were transmitted to offspring very quickly was solved thanks to the neural crest hypothesis.
The neural crest hypothesis began to resonate 10 years ago. With it, researchers have shown how the changes known as domestication syndrome occur during embryonic development and as a result of heritable changes due to the influence of the environment.
It turns out that the activity of the neural crest cells is highly conditioned by the environment in which the embryo develops. Surprisingly, changes due to alterations in this environment modify the DNA or genes of the neural crest. Such modifications are transmitted and maintained in the offspring. This phenomenon is known as epigenetics and seems to have been key in the processes of domestication .
The observable morphological changes in dogs and other domestic animals would not be the result of one-by-one selection of certain genes related to the tameness trait. Rather, they would be the consequence of epigenetic processes on the cells of the neural crest, affected by an environment in contact with the human being, and that would be inherited in the offspring.
Really, is a dog less aggressive than a wolf?
Many studies ensure that dogs are not less aggressive than wolves, but rather that they are species that act differently due to their adaptation to different ecological niches.
In the experiments carried out, the wolves showed less aggressive behavior with members of their pack. This is explained because these attacks would weaken the group, an important aspect for survival.
Unlike wolves, dogs:
- They don’t live in herd
- They are not monogamous
- They do not hunt in groups or share prey.
With this, it has been found that dogs show a greater number of aggressive behaviors with other dogs in their social group.
However, tolerance towards other individuals outside the social group is greater in dogs than in wolves. This aspect has been attributed, by many scientists, to the process of socialization and habituation in contact with humans, rather than to evolutionary differences.
Do dogs understand us better?
Dogs must be understood as animals that have adapted to a specific social and ecological niche. In addition to having been shaped in their selection by the guidelines of the human being.
Several studies have shown that dogs are extremely adept at following our directions and signals. However, the observation that wolves also possess these communicative abilities with humans has also been cited in several investigations.
About dogs, humans and love
The oxytocin system is present in dogs and humans, functioning in a similar way.
Thanks to the secretion of this hormone, the ties between different individuals are strengthened.
The curious and remarkable thing is that this system works in an interspecific way, segregating itself, for example, when a dog and its owner or guardian meet again after a time apart.
It seems that this structure would not be present in wolves.
Therefore, we can say that the fact that dogs are dogs is the result of affection between them and people.
On tenderness and affection in dogs and humans
It seems that there are also certain genes responsible for the appearance of muscles above the eyes of dogs, whose movement would be responsible for arousing reactions of tenderness and affection in people.
These muscles would be the “eyebrows” that your dog moves while you eat and leans on your thigh, making you feel sorry to give him food.
Dogs with these more developed muscles have been shown to be more easily adopted from shelters. For this we say that they are experts begging.
Some of these muscles seem to be absent or very residual in wolves.
Conclusion:
The way in which dogs came into our lives still holds mysteries. But it is very likely that love played a fundamental role.
References:
Anastasiadi, D., & Piferrer, F. 2019. Epimutations in developmental genes underlie the onset of domestication in farmed European sea bass. Molecular biology and evolution, 36(10), 2252-2264.
Range, F., & Marshall-Pescini, S. 2022. Comparing wolves and dogs: current status and implications for human ‘self-domestication’. Trends in Cognitive Sciences.
Rubio, A. O., & Summers, K. 2022. Neural crest cell genes and the domestication syndrome: A comparative analysis of selection. Plos one, 17(2), e0263830.
Skoglund, P. et al. 2015. Ancient wolf genome reveals an early divergence of domestic dog ancestors and admixture into high-latitude breeds. Current Biology, 25(11), 1515-1519.
