"Networked" Web Extra: Sidebars and Video

The feature article "Networked" in the May-June issue of Harvard Magazine explores the work of five network scientists at Harvard and their connections to other researchers in this dynamic, discipline-melding field. Read the article to learn how networks have shed light on public health, human evolution, creativity, and language. Then navigate to our online-only sidebars to learn more:

• In "Costs and Benefits of Connection," read more about the work of Nicholas Christakis, James Fowler, and their collaborators, including their responses to critiques of their work.
• In "Networks, Neolithic to Now," learn how the structure and other attributes of human social networks persist across societies and through time—and about evidence for these attributes' basis in our genes.
• In "Virtual Friendship, for Real," read about research on online human social interaction, and striking parallels between the online and offline worlds.

The videos below demonstrate the problem-solving power inherent in networks. Here, see physarum polycephalum (slime mold) solving a maze in the lab; the mold was more efficient than graduate students at finding the exit route.

Video by Toshiyuki Nakagaki

In this video, see the slime mold form a map of the Tokyo-area railway system. When the researchers place food at cities on the map, the fungus "collaborates," spreading out to map many possible configurations and then dying away to highlight the shortest routes between cities and the most efficient overall system map.

Video by Toshiyuki Nakagaki