Definitions of life become arbitrary as the molecular size diminishes. But an evilutionist would probably that the essential qualities of a living unit are replication and susceptibility to variation and selection. It is not unreasonable to include prions, because -- as our ID proponent in chief has pointed out -- proteins do not occur in the absence of living processes.
How would you classify an obviously living thing that cannot reproduce without the presence of specific other living things? Is a parasite dead if there are no hosts? If not, is a virus alive in the absense of a host? Is a prion?
This evilutionist doesn't. I think the hallmark of life is a complex metabolism feeding on a relatively simple environment.