Feeding the Birds Feeds Their Evolution

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Humans undeniably make a huge impact on the world. We are shaping the Earth's climate, its habitats and ultimately their inhabitants.

But did you ever think something as simple as throwing some crumbs to our feathered friends are driving their evolution? Probably not. Some birds have become so dependent on humans for food that is has changed their migratory pattern and their wing shapes.

Over 3.5 years, scientists in Germany studied the migratory patterns of birds called blackcaps. The birds has split into two groups with significant different routes. One set of birds migrated from Central Europe to southwestern Spain, the other to northwestern UK.

The newer pattern to the UK is shorter than to Spain. As a result, these lazier birds have rounder wings that give better maneuverability, but makes them ill-equiped for flying long distances. Their bills are also more narrow than their Spanish-destined counterparts who eat large fruit.

Surprisingly, these birds are raised in the same forest side by side but do not interbreed. The split into two distinct populations occurred in less than 30 generations.