Visualizing the Invisible Lines
Conservation biologists graphically map interactions between species
Rose Eveleth • September 24, 2010
“When we try to pick out anything by itself we find that it is bound fast by a thousand invisible cords that cannot be broken, to everything in the universe,” John Muir wrote, in his journal in 1869.
Today, scientists are still interested in finding those connections. “We want to make those invisible cords visible,” said Eric Sanderson who created Muir webs as a component of his research for the Wildlife Conservation Society in New York City. This one represents the interactions between species and their environment on Manhattan in the year 1609, when Dutch explorers first sailed up the Hudson.
Each little dot on the image, from which the lines radiate, is either a species (beaver), or a group (nuts), or a habitat (wetland), or simply a physical element (soil moisture). The lines between dots indicate need – a beaver needs a stream, for example, so there’s a line between the two.
It’s an odd way of going about things, and the web doesn’t take into account a whole host of important factors like microbes, invertebrates (aside from butterflies and dragonflies), competition for resources, or temporal relationships. Were those to be added, it might look entirely different.
But, Eric says, it’s just as much art as it is science (here he explains in detail how the webs are built). Without labeling or explanation, this big picture doesn’t really tell us anything. We don’t know what each dot is, or even, what kind of dot it is. It’s just a big mash of dots connected by lines that we don’t know anything about.
The Manahatta website does a good job of turning this mash into something educational. There, you can click around a highly magnified and labeled version of web, and learn about the interactions between the forest and the big brown bat, the squirrel and the nuts and the beaver and the river. Or, if you’re like me, you can just stare at the complete image and feel very, very small.
Good stuff, Rose!