Study Warns Against Comparing Human Migration to Biological Invasions

Scientists highlights the risks of using invasion biology metaphors in migration debates

Drawing parallels between human migration and biological invasions can be misleading and potentially harmful, particularly in the current political landscape, where immigration remains a contentious issue in Europe and the United States. A study published in Biological Reviews—involving researchers from 42 institutions across 23 countries—warns that framing migration through the lens of invasion biology distorts public perception and reinforces xenophobic narratives. The study included Portuguese researcher Ronaldo Sousa, from the Centre of Molecular and Environmental Biology (CBMA) at the University of Minho.

While both biological invasions and human migration involve movement and adaptation, they are fundamentally distinct processes. Biological invasions refer to the introduction of non-native species and their ecological impacts, whereas human migration is shaped by social, political, environmental, and historical factors. According to Ronaldo Sousa, applying invasion science terminology—such as alien, exotic, invasive, or eradication—to human migration “oversimplifies complex realities, fuels fear-based narratives, and misrepresents the role of migrants in society.”

The study, Parallels and Discrepancies Between Non-Native Species Introduction and Human Migration, also highlights how political discourse has increasingly adopted invasion metaphors to frame migration as a threat. “This language dehumanises migrants and promotes alarmist rhetoric,” explains Sousa.

By analysing historical contexts and the sociopolitical impact of terminology, the researchers emphasise that, unlike biological invasions—which can cause severe ecological and economic disruptions—human migration has always been an integral part of human history, contributing to cultural and scientific progress.

The authors advocate for a more interdisciplinary approach that bridges natural and social sciences, ensuring that migration and environmental policies are informed by scientific evidence and ethical considerations. By fostering a more accurate and responsible discourse, the study aims to support policymaking that upholds human dignity and encourages global cooperation.

Read the full press release in portuguese HERE .