Animal dissection was once part and parcel of teaching. Students learned about body organs such as eyes, hearts, kidneys and lungs by dissecting animals from worms and locusts to frogs, fish, rabbits and rats. All children studying biology would be expected to dissect at least one whole animal. Learning about how the organ systems were laid out and worked together was considered to be essential to gaining an understanding of how biological systems functioned in animals. Plant dissections were also common, with students taking apart and looking at the structures of flowers and seeds.
Dissection still forms part of science teaching but attitudes towards the practice have changed. It is much more likely now that the students will watch a teacher perform a dissection than do one themselves. And with access to high-definition video images and three-dimensional simulations, the question is: should we still be cutting up animals?
Yet an interactive frog dissection is not the same as real life. Looking at three-dimensional images of the heart cannot substitute for seeing and feeling how the walls of the chambers vary in thickness and how the various blood vessels feed into and out of this essential organ.
Some fear that children are too squeamish to look at, let alone do, a dissection - and for a few that has always been the case. Certainly no child should be forced to perform a dissection against their will. However, many overcome their initial revulsion and are truly captivated by seeing first-hand the structure of once-living things and how they functioned.
There are skills to be learned from dissection that virtual systems cannot replicate. Patience and precision are needed to see the finest structures, learn how to handle scalpels carefully and manipulate delicate instruments. This kind of proficiency is useful everywhere, not just in biology.
Dissection should not be gratuitous. If the only justification is to add some "entertainment" to a lesson then it has no place. What we dissect should also be carefully considered. Breeding lab rats for the sole purpose of killing and dissecting them is hard to justify morally. But using animals bred and humanely killed for the food chain is acceptable. Buying whole rabbits from the butcher, or obtaining fresh hearts and kidneys, can, when used in a well-planned lesson, be instructional in a justifiable way.
Seeing and handling the real thing - arteries, veins, nerves and organs - does so much more than a video, photograph or animation. For those who go on to work as doctors, surgeons, dentists and in many other related fields, the skills of dissection are vital. While virtual and online interactive dissection may help, I don't want the first cut that my surgeon makes on real flesh to be on me as I lie on the operating table.
James Williams is a lecturer in science education at the University of Sussex. Follow him on Twitter @edujdw
Guide students through a heart dissection with raj.nandhra's illustrated worksheet.
Turn the art of dissection into a double lesson with an extensive lesson pack, including an audio clip of the heart beating, from jhayward2.