# The Evolutionary History of Domesticated Pigs Per Jensen explores ten millennia of selective breeding and its impact on swine biology. - **Source:** [Svenska Dagbladet](https://www.svd.se) - **Published:** 2026-11-06 - **Topic:** [science](https://brifing.si/c/science) - **Original article:** - **On Brifing:** https://brifing.si/s/820d9c2c-754b-4eff-a0cd-ed4e7c4fbf13 ## Ten Millennia of Domestication Domesticated pigs share a common ancestry with wild boars, tracing back ten thousand years of human intervention. Per Jensen’s book, Grisens okända värld, examines how this extensive period of selective breeding has fundamentally altered the species. The narrative explores the biological transformation from wild forest dwellers to the massive animals found today. ## Extreme Weight Disparities A mature wild boar typically weighs as much as a standard piano, reflecting its natural evolutionary state. In contrast, a domesticated boar within the modern meat industry can reach four hundred kilograms. This weight is comparable to a concert-model Steinway grand piano, illustrating the massive physical changes driven by intensive agricultural breeding practices. ## Industrial Breeding Mechanisms The massive size increase in industrial pigs is not accidental but the result of centuries of deliberate selection. Breeders prioritized traits that maximize meat yield, leading to significant physiological shifts. These animals are now engineered for specific industrial purposes, raising questions about the biological limits and health consequences of such rapid artificial evolution. ## The Question of Overbreeding A central theme in Jensen’s analysis is whether these animals have been subjected to excessive breeding. The term 'sönderavlade' implies a state where genetic selection has pushed the species beyond its natural biological capacity. This inquiry challenges readers to consider the ethical implications of prioritizing industrial output over the animal's natural physiological integrity. ## Biological Heritage vs Industry Despite ten thousand years of human-led evolution, the fundamental nature of the pig remains tethered to its wild boar origins. The book highlights the tension between the animal's ancestral instincts and the constraints of the modern farm. Understanding this duality is essential for grasping the true cost of our current food production systems. ## Documenting the Transformation The work features photography by Julia Lindemalm, providing a visual record of the physical reality of these animals. Spanning one hundred and seventy pages, the text combines scientific observation with accessible prose. This documentation serves as a critical bridge between academic research on domestication and the public's understanding of agricultural animal welfare. ## Evolutionary Context of Swine Pigs are highly adaptable mammals that have co-evolved with human civilization since the Neolithic period. This long-term relationship has turned them into one of the most significant livestock species globally. By analyzing their history, researchers can better understand how human needs have reshaped the genetic landscape of the animals we rely upon. ## Future of Animal Breeding The ongoing debate regarding the ethics of animal breeding continues to gain momentum in scientific circles. As we look forward, the focus shifts toward balancing productivity with animal health and genetic diversity. Jensen’s research provides a necessary historical foundation for these discussions, emphasizing the long-term impact of human choices on animal biology. ## Sources covering this story - https://www.svd.se/a/L3V6L4/trots-10000-ars-avel-grisar-fortfarande-svin?utm_medium=rss — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._