Minteer, B. A., Collins, J. P., Love, K. E., & Puschendorf, R. (2014, April 18). Avoiding (Re)extinction. Science. American Association for the Advancement of Science (AAAS). doi:10.1126/science.1250953 (paywall)The authors argue that "The availability of adequate alternative methods of documentation, including high-resolution photography, audio recording, and nonlethal sampling, provide an opportunity to revisit and reconsider field collection practices and policies."
This has brought a swift response from Kevin Winkler (Re)affirming the specimen gold standard who argues that physical specimens are vital for much of the science that museum collections support.
At the same time, David Schindel has posted on Minimum standards for e-voucher documentation, that is, DNA samples where no physical voucher exists (e.g., because the organism is a member of an endangered species, or still alive).