How Humans Shaped the Genes of Pets and Livestock.

Big eyes, wagging tails, and playful affection—these beloved traits in pets aren't merely adorable quirks; they are products of centuries of domestication embedded in animal DNA. The process began more than 15,000 years ago when early humans, still hunter-gatherers, formed bonds with wolves. Over time, selective breeding gave rise to domestic dogs and later extended to other animals such as sheep, goats, pigs, cattle, chickens, and horses for food, labor, and companionship.

Modern genomic tools are now helping scientists unravel the genetic blueprint behind domesticated animals. According to Pam Wiener, an animal geneticist at The University of Edinburgh, this research can guide future breeding strategies and help us understand how animals evolved alongside humans.

Researchers have used various genetic markers to compare domesticated animals with their wild counterparts. Microsatellites—short, repeating DNA segments that mutate rapidly—help identify genome regions linked to traits like meat production. Complementary studies use single-nucleotide polymorphisms (SNPs) to pinpoint specific genetic variations between domesticated and wild animals.

Recent advances in next-generation sequencing have further deepened this understanding. Scientists can now extract and analyze ancient DNA from archaeological remains and museum specimens. When compared with the DNA of modern animals, these studies reveal the origins and evolutionary pathways of domesticated species.

Findings show that domestication involved more than just enhancing productivity. In dogs, for example, two genetic variants were linked to increased sociability—traits that likely encouraged stronger bonds with humans. In cattle raised for meat, scientists identified a deletion in the myostatin gene. This gene typically limits muscle growth, and its absence led to the development of highly muscular, lean animals. Over generations, farmers selectively bred this trait into specific cattle breeds.

But practical benefits weren’t the only selection criteria. As Wiener noted, humans often chose animals based on aesthetic appeal. Traits like coat color were frequently targeted. Domestic pigs, for example, have developed mutations in the melanocortin receptor 1 gene, which affects skin and hair pigmentation. Similarly, most white horses carry a mutation that causes early graying, resulting in their lighter coloring.

These visual traits may have served practical purposes, such as helping farmers distinguish among animals. However, some features—like dogs’ floppy ears and rounded skulls—seem to reflect human preferences for childlike appearances.

Over millennia, people have bred animals to meet both practical and emotional needs. What may seem like charming quirks in pets today are, in fact, the result of deliberate genetic shaping by humans across generations. These changes not only illustrate human influence but also tell a broader story about the intertwined paths of animals and people throughout history.

Source:https://www.the-scientist.com/the-genes-that-shaped-pets-and-domesticated-livestock-73090

This is non-financial/medical advice and made using AI so could be wrong.