Anthropogenic evolution in an insect wing polymorphism following widespread deforestation.

Area of Science:

• Evolutionary biology
• Ecology
• Environmental science

Background:

• Anthropogenic environmental change alters selective pressures on wild populations.
• Deforestation's evolutionary impacts on terrestrial ecosystems are poorly understood.
• Exposure due to forest removal may select for insect flightlessness in mountains.

Purpose of the Study:

• To investigate if deforestation-induced changes in alpine treeline elevation have shifted phenotypes in New Zealand stoneflies.
• To test the link between human-driven deforestation and the evolution of flightlessness in *Zelandoperla fenestrata*.

Main Methods:

• Utilized human-driven variation in alpine treeline elevation in New Zealand.
• Conducted transect sampling of stonefly populations across elevational gradients.
• Analyzed phenotypic distributions of flight-capable and flightless morphs in relation to treeline elevation.

Main Results:

• Observed sharp transitions from flight-capable to flightless stonefly populations with increasing elevation.
• Found that these phenotypic transitions were consistently aligned with local treeline elevations, not absolute altitude.
• Demonstrated a novel instance of human-driven evolution linked to recent deforestation.

Conclusions:

• Deforestation has driven rapid evolutionary shifts towards flightlessness in stonefly populations.
• Treeline elevation, influenced by human activity, acts as a key factor in this evolutionary response.
• Findings have significant implications for understanding invertebrate evolution and biodiversity conservation in deforested landscapes.