For anyone keeping up with the lively exchanges between the scientific community and animal rights activists (which are not always mutually exclusive — looking at you, Jane Goodall), 2016 has been a doozy. Not only are everyone’s favorite black-and-white whales being phased out from SeaWorld, but the National Institutes of Health (NIH) announced in March that it’s going to release its collection of chimps used for medical research [1,2]. It was also publicized earlier this year that Santa Cruz Biotechnology, the second-largest vendor in the animal-derived antibody market, suspiciously ‘lost’ a few thousand goats and rabbits from their inventory after numerous animal welfare complaints [3,4].

Given that a prolific number of medical advances and the initial trials of nearly every pharmaceutical product have all been extensively informed by animal research, it’s interesting to consider from a modern standpoint the effect that animal rights activism has had on scientific progress. By challenging scientists to approach research with different tools, animal rights activists have influenced what experiments can be conducted and thus shaped the field at large.

The concern for animal experimentation in scientific research is not new. Whereas members of elite British literary circles criticized physicians who experimented on live animals as early as the 18th century, these criticisms were but a foreshadowing of the virulent antivivisection movement that defined animal ethics in the nineteenth century [5,6]. This shift from private to public opposition was largely driven by an increasing awareness of the controversial techniques used by experimental physiologists. At the time, vivisections were often performed during public lecture demonstrations. However, the public misunderstood how these experiments would benefit society – a lot of methodology was crude, and there was an additional xenophobic concern that organized medicine in Britain was following a barbarous path blazed by French and German physiologists [5]. Partially in response to a public outcry in London following an infamous public greyhound vivisection conducted in 1824 by François Magendie, the physiologist Marshall Hall became an outspoken proponent for a set of guidelines to govern how animal experimentation should be conducted [6,7].

Hall’s deliberations, which argued that animal research should only be conducted when its benefit was clear and that pain to the animal should be minimized, were largely drawn upon in the development of the Cruelty to Animals Act 1876 [5,8,9]. For antivivisectionists, the Cruelty to Animals Act was proof that their efforts were being heard; for scientists, research efforts were temporarily hampered as the act required them to obtain legal permission to perform a vivisection with animals, to use anesthesia during their experiments unless permitted under special consideration, and to state a clear benefit to humanity for conducting their research [6].

Over a century passed before the Cruelty to Animals Act was replaced with the Animals (Scientific Procedures) Act 1986, which defined regulatory procedures for using vertebrate, non-human model organisms for research [5,10]. Importantly, the new act also followed what we now recognize as the animal rights movement, which was begun in 1970 by a young group of Oxford philosophers. An important text written at the time by Peter Singer, Animal Liberation: A New Ethics for Our Treatment of Animals, captured their beliefs and popularized the concept of anti-speciesism, which argues that animals should be treated ethically because they have the ability to suffer [11]. With the resultant Animals Act, the opinions promulgated by the animal rights movement and the public at large have defined the legal and moral parameters with which every scientific researcher working with animals today must comply.

As researchers adapted to the demands placed on them by activists, their work became necessarily regulated, government-sanctioned, and focused. Researchers were required to carefully state and develop the problems they wished to address with the animal research in their projects. But what kind of regulations are involved now? For starters, if you head a lab and you’re interested in researching some biomedical problem, there’s a good chance that you’re going to want some money to fund that research. If you want that money from the NIH (and the chances are you do), then you and your lab will need to comply with the Public Policy on Humane Care and Use of Laboratory Animals (the PHS policy) and the Animal Welfare Act and Regulations [12]. Any investigator in the country who works with animals will at some point have designed a protocol specifying which animals they will work with, how many they’ll work with, how the animals will be cared for, how they’ll be studied, maintained, and used in experiments, and why it’s necessary for the success of the project that they be used at all. Before any research takes place, this protocol will first have to be approved by an institutional animal care and use committee (IACUC). On top of that, your institution must also have an accredited animal research program that has IACUC approval and assurance, effectively preventing any homespun animal research dilettante from starting up a project they couldn’t realistically handle. Like credit cards and library books, institutions must renew their policies too, about every four to five years, and the NIH also strongly advises that all animal facilities maintain accreditation by the Association of Laboratory Animal Care International.

And those are just the most basic rules. These policies each come with individual and detailed requirements, university courses, training sessions, and individual applications for institutions, lab directors, and the researchers who work for them. The NIH requirements for anyone to work with animals spell out a glaring hurdle in the form of time and money. It is here, at the extensive legal barrier to government funding, that animal activism is most powerful, capable of influencing the scientific approach of researchers inside the lab by calling for legal measures that must be adopted by scientific practice before the research can effectively continue.

Considering milestone events like the retiring of NIH chimps used for research begs an interesting question: Why do changes finally happen in science? In the case of vertebrate model organisms like mice or chimps, there is often a cause-and-effect relationship in which activists can successfully sway public opinion, which sways lawmakers, who hold hearings, deliberate, ideally talk with scientists during those deliberations, and finally vote to change or keep a policy. These changes demonstrate that scientists also think about their research from an ethical standpoint and will reframe experimental approaches to minimize the involvement of animal life whenever possible, especially when the research can be continued without them [2].

However, when the NIH announced that its chimps would be released, their explanation suggested that there was less of this cause-and-effect relationship and more of a new-technology-has-rendered-these-chimps-obsolete relationship. The utility of a model organism depends on its relevance, and the rule of thumb for the hierarchy of model organisms that scientists use is, the simpler the better. If genetic engineering tools mean that you can use a mouse instead of a chimp, then you use the mouse; if Alzheimer’s disease can now be studied as effectively in a fruit fly rather than a mouse model, then using a mouse becomes obsolete in favor of the fly.

The use of animals in scientific research operates in a way that has historically adapted to external legal measures. However, as the genetic methods and scientific technology used in biomedical research continue to develop, it will be interesting to see which factors drive the changes made to experimental practice.