Detail of White Cat (1935-38), by Gertrude Abercrombie (Smithsonian American Art Museum)

Try to make the distinction between a thing that is alive and life itself. What happens? For SFI Professor Michael Lachmann and SFI External Professor Sara Walker (Arizona State University), if we can get better at drawing the contrast, we can build stronger scientific theories for understanding the living world.

While it seems like a simple thing to point to something that is alive, when we look at cases that challenge our intuitive first impressions, we open up difficult terrain. A cat seems obviously alive; a virus, alternatively, is hard to pin down. On the one hand, a virus seems to be alive: it behaves in ways that resemble the behavior of obviously living things. On the other hand, viruses don’t seem to be alive: they depend on host cells to copy themselves and cannot reproduce on their own. What do we make of the fact that viruses seem to act like living things in some ways and not in others? Can we say that viruses exhibit some of the patterns of life?

In their essay for Aeon, Walker and Lachmann argue that we would do well to understand life as a process of transmitting information. When we begin to think of life in this way, as opposed to thinking of it in terms of the phenomena we recognize as obviously alive, we have a clearer basis for understanding the core processes that underlie all of life.

Read the essay in Aeon (June 24, 2019)