The domestication of animals: origins, general characteristics and stages

In the last few years, the idea that human development has been altered by the cultural changes and transformations that have occurred throughout the centuries seems to have gained ground. Indeed, these cultural processes have an obvious impact on human evolution.

One of the most important cultural renovations in our history took place over 10,000 years ago, when a society of hunters and gatherers evolved into new types of human communities that started to produce their own food. To do so, this new society started to domesticate both animal and plant species. Domestication was a circumstance that emerged spontaneously in a number of population centres, which led to a new way of life: farming and stockbreeding. This discovery actually had a huge impact on the lifestyle of human populations.

In this post, we’ll focus on the historical significance, the origins and the different stages of animal domestication. We’ll also go through some features and general ideas about domestic animals.

What makes an animal ‘domestic’?

Domestic animals belong to species (or populations thereof) that don’t exist in wild forms, but are maintained by humans for their exploitation, which is carried out in captivity. These animals are, therefore, unable to survive in the wild, even if they maintain their phenotypic traits.

It’s important to note that there are also semi-domestic or tamed animals, which are those that are exploited by humans and can be held captive, but don’t fulfill all the conditions mentioned above. Examples of semi-domestic or tamed species are falconry birds and ostriches, which are now farmed for different purposes, as well as Asian elephants, whose offspring are captured, tamed and domesticated for their further exploitation. In fact, these cases can probably be considered examples of early stages of the domestication process.

The origins of animal domestication

The domestication of animal species is associated with an increase in the size of the human population, and, apparently, this practice emerged in different regions at different times (multiple origins). It’s quite likely that the appearance of this practice took place in a period with a marked climatic seasonality, which caused instability in the environment (dry, hot summers and cold winters), forcing the population to look for new and more efficient ways of exploiting resources.

During these unfavourable climatic periods – and especially in low-productivity areas (regions with extreme conditions) – it was more profitable to put animals in a stable to look after and rear them than to hunt them, which also required a huge physical effort.

The oldest domesticated animals

Why were some animals domesticated and others not?

It’s likely that, prior to domestication, there were some ‘candidate’ species that met a series of requirements to achieve different goals. The first animals to be domesticated were those that, apart from being a source of food, could also be used as a mechanical force to produce food crops more efficiently; that is, animals that could be used as tools in agriculture. The first candidates were terrestrial mammals of over 45 kilos of weight.

These animals also had to be herbivores or omnivores, so they could be fed a plant-based diet (or another type of diet, in the case of omnivores), food that can easily be obtained or produced by humans (unlike foods of animal origin, which are harder to get and that would have been needed to feed carnivore species).

Physical and ethological characteristics of domestic animals

As we just saw, domestication involves a selection process, so domestic animals will have common characteristics as a consequence of human needs and preferences. These traits appear as a result of the selection of the agriotype – that is, the population of species whose genotype and phenotype were not manipulated by mankind –, who live in the wild and from which domesticated populations derive.

In other words, an agriotype is the wild counterpart of a domesticated animal. In general, the appearance and body proportions of domestic animals are different to those of their agriotypes. This can be reflected, for example, in a smaller body size, shorter horns or limbs (limited defence capabilities) or in a reduction of the ability to fly in birds (as is the case of hens). In addition, some internal traits are more variable in agriotypes, such as the skeleton or dentition.

On the other hand, the behaviour of domestic animals is also altered; they’re generally more docile and manageable, and present a comparatively earlier maturation. They also have a number of common ethological traits that made domestication easier: they’re more tolerant to humans, who they allow to play a dominant role, and are more sociable with other individuals of their species, which means they can live in groups. Lastly, the domestic species are more rustic; they have a greater tolerance to changes in their environment and diet.

The stages of the domestication process

Different stages are generally observed in the domestication process. First of all, it’s important to mention that a period of peaceful tolerance between the animal and humans is necessary during this process. It should allow for some type of relationship to develop, which can even be an association that both will benefit from (may that be because it provides food, protection, etc.).

After this bond is established, it’s easier to keep the animal confined in a controlled space, in order to tame it. Therefore, by rearing animals under controlled conditions, humans obtain highly tolerant individuals.

General implications of animal domestication

The establishment of domestication as a new way of exploiting the environment had significant consequences for the way of life and structure of human populations. While early hunters and gatherers kept their nomadic ways, the new societies of farmers and cattle breeders led significantly more sedentary lives, which helped increase the size of populations. This new lifestyle also allowed the communities to save physical energy, as they no longer had to constantly relocate nor spend long days hunting.

Besides, the majority of the population was involved in the production of new foods, which provided a more balanced diet, rich in carbohydrates and vegetable protein. Diet became particularly important, as it has a huge impact on the health, size and structure of populations.

Translated by Carlos Heras