Scientists reveal Darwinian evolution through genetic evidence of lactose tolerance in humans

The University of Montana Community Lecture Series took a deep dive into the fascinating world of evolution during its third session on April 17, 2025. The spotlight was on Darwinian evolution, with a focus on how modern science continues to unveil the complexities of natural selection.

One of the standout discussions revolved around the evolution of antibiotic resistance in bacteria. Experts highlighted how bacteria that possess natural immunity to antibiotics thrive, while their vulnerable counterparts perish. This phenomenon exemplifies Darwinian evolution, showcasing how populations can change over time through natural selection.

The lecture also explored groundbreaking insights from genetics, particularly through the sequencing of the human genome. A compelling example discussed was lactose intolerance. It was revealed that adult mammals typically lose the ability to digest lactose, as only young mammals consume milk. However, genetic studies have shown that certain human populations developed the ability to produce lactase, the enzyme needed to digest lactose, coinciding with the domestication of livestock. This adaptation provided significant survival advantages, allowing those with the mutation to thrive in challenging environments.

Moreover, the discussion touched on the interplay between cultural and natural evolution. As noted, evolution is not solely a response to environmental factors but also to cultural changes. This emerging field, often referred to as evolutionary psychology, examines how human behaviors and cultural traits evolve through natural selection.

The implications of these findings are profound, suggesting that evolution is a dynamic process influenced by both biological and cultural factors. As researchers continue to uncover these connections, the understanding of human evolution and adaptation will undoubtedly expand, offering new perspectives on our past and future.