Photojagodka / DepositPhotos
Domestication has made cats and dogs more diverse, but also curiously similar-with serious implications for their health and well-being, reveals new investigation.
At first glance, Persian cats and pugs do not seem to have much in common. One is a cat, the other is a dog, separated for 50 million years of evolution. But when biologist Abby Grace Drake and her colleagues examined 1,810 skulls of cats, dogs and their wild relatives, they discovered something strange. Despite their distant stories, many breeds of cats and dogs impressive similarities in the form of the skull.
In evolutionary biology, divergence is a common process. Simply put, divergence is when two organisms that share a common ancestry become increasingly different over time, while convergence means becoming more similar. As animal populations are divided and adapts to different environments, they gradually develop new characteristics, a process known as Divergent evolution.
This is one of the main ways in which new species form different characteristics, causing populations to evolve by separate paths. But sometimes evolution can take a different course. THE convergence occurs when unbleed species, molded by similar pressuresevolve independently to similar characteristics.
In the case of domestic cats, dogs and many other domesticated species, the intentional and unintentional selection by humans It seems to have created convergence, accidentally leading different species to develop similar characteristics.
Despite a long history of evolutionary separationflattened races, like the Persian cat and the pug, share similar cranial structures.
To investigate to what extent domestication remodeling the structure of the skull, Drake and his colleagues analyzed 3D skulls scanning of museum species, veterinary schools and digital archives. Its data set included domestic cats, such as Siamese, Maine Coon and Persian races, as well as more than 100 dog breeds, from short muzzle dogs such as pugs, to long muzzle races, such as collies.
Their findings showed that domestication not only increased the diversity of the skull shape In addition to the wolves and wild cats, but also led some breeds of cats and dogs to resemble each other, with convergence for long or flattened faces.
Wild canids (the group of animals that includes dogs, wolves, foxes and chakal) tend to share a similar elongated skullwhile wild felines (the group of animals that includes household cats, lions, tigers and jaguars) have a more natural variation.
However, domestic races of both species now cover a more extreme range at both ends of the scale. This trend can be observed in the emergence of cats raised to look like XL Bully dogs.
Domestication has long shows that when humans intervene, even distant species can end It seems, and sometimes suffering in similar ways.
Selective reproduction exaggerated character in several species. Many other changes caused by man can carry animals beyond what their bodies can bear naturally. For example, some chickens raised for consumption have 30% of their body weight in muscles pectorals, which often results in heart and pulmonary problems.
Human preference for flattened crumbies affects some of our most fundamental instincts. Human beings are programmed to respond to children’s characteristicslike rounded heads, small noses and large and low eyes. These characteristics, which are exaggerated in many races of cats and dogs of flattened muzzle, imitate the appearance of human babies.
Of all species, humans are among the most altricwhich means that we are born defenseless and dependent on caregivers to survive, a feature we share with dogs and kittens. In contrast, early animals are able to see, hear, stand and move right after birth. As human babies depend so much on adult care, evolution has shaped us to be sensitive to signs of vulnerability and necessity.
These signs, such as rounded cheeks and the big eyes of babies, are known as social triggers. They trigger care behavior in adults, from speaking of sharper tones to offering parental care.
Gavotes-Argens are an example of this in nonhuman animals. Its instinctively pupils are a red spot in their parents’ beak, which causes adults to regurgit food.
This red spot acts as a social trigger, ensuring that the needs of the puppies are met at the right time. Similarly, the domesticated animals effectively “Kidnapped” ancient mechanisms of care that evolved to our own descendants.
These characteristics can give pets an advantage in the request for human care and attention, but have a cost.
The UK government is in charge of its animal welfare committee to provide independent specialized counseling on animal welfare issues. In reports produced in 2024, the committee raised serious concerns about the Effect of selective reproduction on cats and dogs.
The reports pointed out that reproduction to obtain extreme physical characteristics, such as flat faces and exaggerated forms of skull, led to widespread health problems, including respiratory difficulties, neurological conditions and childbirth complications.
The committee argues that animals with serious hereditary health problems should not be used for reproduction and calls for more rigorous breeders regulation. Without these reforms, many popular races will continue to suffer of preventable conditions that limit life.
Selective reproduction demonstrated how humans can easily shape nature According to their preferences and as millions of years of evolutionary separation can be annulled in a few decades of artificial selection.
