The newest genome-mapping has shown that human beings and chimpanzees share more than 99 percent sequence identity in genes and proteins, while having accumulated more differences in the rest of their DNA. Indeed, the great apes - chimpanzees, bonobos, gorillas and orangutans - are now grouped with humans in the family Hominidae. Their close kinship to us makes them interesting to scientists, and research institutions, sanctuaries, zoos, private owners and the entertainment industry together house more than 2,000 great apes, most of them West African chimpanzees.
The UCSD scientists want to make sure that the biomedical community recognizes the great apes' unique status as near-kin. "We have special ethical responsibilities towards captive great apes," they say in the Sept. 1 issue of the journal Nature, in an article accompanying the formal publication of the chimpanzee genome. "They share traits -- including but not limited to, their genetic similarity to humans, the ability to use and modify tools and a sense of 'self' -- that justify this special status."
Pascal Gagneux, James J. Moore and Ajit Varki of UCSD argue in Nature that "the study of great apes should follow ethical principles generally similar to those for current studies on human subjects who cannot give informed consent," and they acknowledge the many grey areas that still perplex researchers.
Is it acceptable, for example, to do "reversible harm," such as causing a mild, treatable infection, or to sedate a chimpanzee (as you might a child) so as to allow therapeutic procedures? Such issues, they say, "deserve much further dialog among all concerned."
Some areas aren't grey for the scientists: Alternatives to potentially harmful forms of research on living chimpanzees should be found as soon as possible; genomic data should never be used to produce "transgenic" apes (as is routinely done with mice); and all biomedical studies on great apes should be carried out in ways that support further improvements to their care.
Noting that both a National Research Council Commission report and a recent Federal Register Notice reemphasize researchers' obligation to provide the "best and most humane care possible" for apes under study, the UCSD scientists argue that "the time has come to establish broadly accepted guidelines for systematic, humane and ethical studies of captive great-ape populations that also contribute to the well-being of the apes themselves. These studies should be carried out at all levels, from genetics to biochemistry to physiology to behavior and culture." Gagneux, a scientist in cellular and molecular medicine who also does endangered-species research for the Zoological Society of San Diego; Moore, a professor of anthropology; and Varki, a professor of both medicine and cellular and molecular medicine, make it very clear that their proposal applies only to the great apes, "and not to other primates, nor other animals."
And, they assert, their concern is "not about animal 'rights' but about ethical and scientific challenges specific to great apes in captivity."
The scientists recommend several practices and policies for research to protect the great apes, even while making fuller use of their contributions to biomedical discoveries:
"We urge all scientists studying great apes," say the authors, "to contribute not only to the care of captive apes, but also to develop mechanisms by which studies of captive great apes would help generate a revenue stream to enhance support for the conservation of great ape populations in the wild."
The UCSD scientists know that their proposal is just the beginning of a potentially contentious process, "unlikely to please everyone currently interested in the great apes," but hope that the resulting dialog in the research community will help develop a mutually acceptable solution for all concerned, including the great apes.
"We will undoubtedly be accused of trying to stand on the proverbial slippery slope," said Varki. "However, depending on one's perspective, this particular slope can incline in either direction. Thus, this is exactly where we wish to be on this difficult ethical issue."
Meanwhile, they note, there is a deep irony in the fact that the sequencing of the chimpanzee genome coincides with the potential demise of great apes in the wild.
"Research on captive great apes will provide precious new knowledge," said Gagneux. "The future survival of these endangered species, however, will depend on conservation efforts in their natural habitats of Africa and Asia."
The work of Gagneux, Moore, Varki and members of the UCSD Project for Explaining the Origin of Humans is funded by the G. Harold and Leila Y. Mathers Charitable Foundation.