The boundary of a nation can meander along a river, lie invisible beneath a forest canopy, or end as abruptly as a fence or a wall. Sometimes, it can be easy to reason where and why these edges exist–one land regime bumps against another or a geographic feature rises up to form impassable terrain. But more often than not, these boundaries do not follow physical logic. It is a patchwork of man-made lines that composes the world map most recognizable to us, carving the planet up into territories managed by 195 different flags. The further we zoom out, the boundaries of the nation-state seem to have very little alignment with the underlying patterns of the natural terrain.

These political lines often disregard the natural necessities and limits that might define a watershed, biome or ecological region. Basins like the Colorado, Nile and Mekong, which spread throughout uncoordinated and competing political entities, have become micromanaged parodies of mighty rivers. Jungles like the Amazon or the Congo Basin, carved up by a mosaic of changing rules, are dying by more than the metaphorical 1,000 cuts. Human migrations are not the only ones halted by metal fences. We forget that borders, which often run absentminded of the ecology system upon which they are overlaid, are anything but natural.

Courtesy of the Apollo 11 mission, the 1972 planetary self-portraits present an alternative view of the Earth: a colored map of the planet’s natural divisions, from desert to mountain to jungle, each distinguished by the life these biomes support. The governing rules of these land masses are their climate patterns, and at the heart of these divisions lies water: where it falls, how much, and the direction it flows. The dividing lines are drawn by the mountain ranges and valleys. Our map of nation states fades to dust.

Yet evermore, the terrain that becomes increasingly apparent from high up are the swaths of urban, gray concrete we are building. The dendritic networks of roads, infrastructures, and buildings that are increasingly slicing up the blue marble into fragments. The grid is overlaid on the delta; static objects are raised in a dynamic environment; the wild is tamed for an economic engine.

This issue considers the conflicts (and synergies) between natural and man-made lines.