Monkeys can be as self-domesticated as humans, studies suggest

New research suggests that monkeys, like humans, may be engaged in the process of self-adaptation, altering their own evolutionary and physiological pathways through the way they interact with each other.

It has long been recognized that animal rearing promotes certain physical features that are not found in their wild counterparts. This phenomenon has been noted since the time of Charles Darwin – what is called homininization syndrome and is believed to be behind all sorts of physical features and characteristics.

While the term ‘humanization’ is often used in animal husbandry situations, it does not always mean that. Scientists have also hypothesized that humans inadvertently choose partners who are self-motivated – less aggressive and exhibit more social behaviors.

The idea is that, over the generations, those choices may produce some more wild and animalistic aspects of our ancient practices, instead promoting tolerance and professional behavior, which in turn can lead to the development of human culture, as we know it. .

That sounds like a convincing argument, but scientists agree that the evidence for this hypothesis is largely circumstantial.

“It’s a really popular and exciting idea, but there’s no direct evidence of it, the link between friendly behavior and other courtyard features,” says Asif Ghazanffer, a neuroscientist at Princeton University.

Thanks to the new research of Ghazanfar and his team, however, we may have identified such a link.

In experiments with marmoset monkeys (Calithrix JacquesThe researchers found that they were the first data to show a link between noisy social behavior in animal species and physical adherence traits in individual animals.

Marmosets exhibit a high degree of social tolerance and pro-socialism and communicate with each other through walking. In previous research, Ghaznfar and his team showed that infant monkeys learn these syllables in the same way that children learn to speak, through social reinforcement from their parents.

This type of parental feedback has an effect on more than just laryngeal technique. One of the well-known markers of spinach in mummies is characteristic of the depiction: a prominent white patch of fur on the foreheads of animals.

Getty Images 453290335Normal marmoset with white patch on forehead. (MB-Photos / Getty Images)

The researchers wanted to investigate whether there was a link between the exchange of sound and this particular morphological trait, which, if found, could be taken as evidence of self-adherence.

In experiments with infant twins from three different momoset families, each infant monkey was given a voice from a ‘simulated parent’: a computer designed for an adult-like sound, which responds to ls. “

However, in these sessions, which have been held for more than two months, one of each pair has given 10 times more noise than his siblings. The researchers found that the amount of noise the animals trained was linked to the size of the white patches of fur on their heads, while the domestic markers appeared larger and increased faster with more discussion time.

“If you change the rate of sound growth of mummies, then you change the rate of fur coloration,” says Ghaznfar. “It’s an interesting and fantastic set of results!”

Researchers suggest that this phenomenon is caused by neural crest cells, a form of stem cell that migrates throughout the body during early development.

One of the derivatives of neural crest cells is melanocytes that contribute to pigmentation, and researchers argue that experiencing more vocal training acts as a simple self-home conditioning that affects the developing body of young marmosets.

Much research remains to be done on how neural crest cells may be involved in these processes, and researchers acknowledge that their study is small and intends to replicate the future in separate research.

Nonetheless, it is a rare thing: experimental evidence of how inter-racial interactions seem to be associated with self-adherence – a progression that may help stimulate additional discoveries.

“The potential involvement of neural Christ cells provides a mechanism by which behavioral experience can be linked to the emergence of morphological phenotypes associated with pets,” the researchers write. “

“This in turn provides a new evolution of how choices on correlated phenotypes can act during human evolution, as hominins have become increasingly dependent on cooperative networks for survival and reproduction.”

These findings are reported Current Biology.