How Humans Have Shaped Evolution

3 March 2026

Genomes are the vast sequence of millions to billions of the A, T, G, and C bases which make up the DNA inside all living things. Thus the genome contains a wealth of information about the biology, evolutionary history, and ecosystem function, as well as the health of an organism. The biological function of most of this blueprint remains uncharted territory, and elucidating it is a primary frontier of modern science. The resulting knowledge holds immense potential for all aspects of biology, and medicine, making it a cornerstone of the teaching and research conducted at SBBS.

In our group, we are interested in understanding how human activity rewrites this blueprint of life. Look around any city or countryside, and the human thumbprint is everywhere. We do not just live alongside nature, we actively reshape it. By building roads, clearing forests, and transporting species across continents, we have become one of the most powerful drivers of change on Earth. 

Our influence goes even deeper than the landscape. For millennia, humans have "played" with the natural world, for example, by breeding dogs that look nothing like their ancestors. In doing so, we have not just changed how these animals look, we have completely derailed their natural evolutionary trajectories. When we change the course of evolution, whether through intentional selective breeding or by accidentally destroying its habitat, we leave a permanent mark. These interventions dramatically shift the frequency of specific gene versions, known as alleles, within a population. By favoring certain characteristics over others, we cement a new evolutionary path for the species that is passed down through every subsequent generation.

Our research group as part of the Centre of Evolutionary and Functional Genomics aims to uncover how human activity has redirected the evolutionary paths of other species by reading the very blueprints where these changes are recorded. To do this, we decode the genomic code that makes up an "instruction manual" for life. By comparing the genomic code of thousands of individuals from species like dogs, wolves, pigs, wild boars, and cattle we can see how their biology has shifted under our influence. 

One of our most powerful tools is ancient DNA. Using specialised techniques, we can reveal the genetic code of animals that died thousands of years ago. This serves as a sort of time machine. By comparing the genomes of ancient animals to those living today, we can catch evolution red-handed, allowing us to track the long-term impact of human history on the living world around us. We track how, where, and why dogs were first domesticated over 15,000 years ago, a period when humans were still hunter-gatherers and agriculture had yet to emerge. We investigate how people have reshaped ecosystems by introducing invasive species, such as pigs and dogs, throughout history and prehistory. We also use ancient DNA to understand how modern interventions, such as the use of vaccinations or antibiotics for livestock, have influenced the evolution of the viruses and bacteria that impact our world today.

In our recent work, we studied the genome of 73 ancient dogs from across Europe and Asia, dating back roughly 12,000 years. Our findings show that dog and human populations have traveled together for millennia, moving across the globe during the great migrations of prehistory. This shared journey spans almost every way humans have lived, from nomadic hunter-gatherers and early farmers to livestock herders and the first city dwellers.

These results show that dogs have not just been a part of human culture for a huge part of our history, but that their genetic code was shaped by the specific communities they lived in. The changes we see in their genomes likely reflect the many different jobs they performed. Dogs were not just pets or hunting partners; depending on the culture, they were also used for herding, transport, and sometimes even as a source of food.

In another study, we analysed the genomes of over 700 pigs from Island Southeast Asia and the Pacific (from Sumatra to Hawaii), from both living and archaeological specimens. We discovered that humans have been deliberately moving pig species across this region for over 50,000 years, beginning with the very people known to be the world's earliest cave painters. The deliberate introduction of pigs on islands across the region accelerated dramatically around 4,000 years ago, following pig domestication, when early agricultural communities transported domestic pigs, alongside rice, from Taiwan through the Philippines and into remote Polynesia. Many of these pigs escaped and became feral, acting as both invasive species and a vital food source for local predators like the endangered Komodo dragon. 

These findings highlight the enduring impact of human activity, stretching back not just over the last century, but for millennia. This raises difficult conservation conundrums: how do we manage species that have been an integral part of an ecosystem for thousands of years, yet began as domestic animals deliberately introduced by humans? Our work suggests that the 'natural' world is inextricably linked to our own history, requiring a more nuanced approach to protecting the biodiversity of the future.

Laurent Frantz is a part of the Centre for Evolutionary and Functional Genomics