Rudolph and Santa: Why Can We Use Animals to Investigate Humans?

In some cases, when carrying out scientific research, you cannot perform early investigations on humans due to ethical reasons. Therefore, to observe the impact of investigations in a real-world setting, rather than relying on theoretical or clinical research alone, we need a substitute to take the place of humans. For example, we could take a strain of Covid-19 and spray a bunch of bleach on it in a lab. Congratulations, we now have a potential way of killing Covid-19, let’s now just inject bleach into people to have the same result…not such a great idea (right Trump?). Ultimately, understanding scientific concepts and solving them in a clinical, theoretical setting, does not always translate into real-world solutions. Animals allow a kind of ‘intermediate’ to suggest how humans might respond, and thus have been vital in helping us understand human phenomena. But why do animals make the perfect ‘intermediate’?

Widya Mulyasasmita, a geneticist from Stanford University, had a very clever way of explaining this. She says that every living organism has a ‘cookbook’ which gives instruction on how to build it. This cookbook is very simple, only using the letters ‘A’, ‘T’, ‘G’ and ‘C’. In total, there are around 3 billion of these letters in the human cookbook. In humans, the cookbook is split into 46 chapters, known as chromosomes. In each of these chapters, there are recipes for eye colour, how to make fingers, and how to build a brain. Therefore, the difference between humans and mice, for example, is that the human cookbook and a mice cookbook have a different number of chapters, and within these chapters have some different recipes, with changes in recipes which they share.

Whilst this explains why animals may differ from humans, it also explains how they are similar. As all living organisms are all made up of the same four letters, there is a lot of overlap between human and animal DNA. It is probably no surprise that humans share 98.8% of our DNA with chimps, but did you also know we share 98% of our DNA with pigs, 85% with mice and 61% with fruit flies? Because of this, there are a significant number of similarities in the anatomy and physiology between humans and animals, specifically with mammals, despite their external differences. Most mammals all have the same organs and systems which function similarly to humans. It is this reason that animals make the perfect ‘intermediate’ to carry out scientific research on, as a model for humans.

We can use animal models to investigate many different areas of scientific research, but a prominent use of animal models is to investigate human disease. We can use animals, such as mice, and systematically ‘turn off’ certain genes, which humans have in common, and seeing what effect this has on the mice. This type of research is called knockout effect and has been used to recreate and understand many different types of human disease, to help find new treatments.

Animal contributions to scientific research have been essential; not only in the field of genetics, but in almost all areas of science. Cows were used to develop the first vaccines; primates have been essential in the development of drugs to treat cancer, HIV, Alzheimer’s, hepatitis, and malaria. Not only should we be thankful to reindeers for flying Santa around the world, but we also owe animals a world of thanks for their previous and continuous contributions in investigating, understanding, and saving humans.

References:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3979591/

https://speakingofresearch.com/facts/the-animal-model/

https://thednatests.com/how-much-dna-do-humans-share-with-other-animals/

https://genetics.thetech.org/ask-a-geneticist/dog-vs-human-dna

https://fbresearch.org/medical-advances/animal-research-achievements/

Disclaimer

The information in this blog is for information and entertainment purposes only. I am not a medical professional, so I have never and will never give medical advice in this blog. You should always speak to a healthcare professional about your unique health needs. My opinions are entirely my own and do not reflect the organisations or people I work for. I only discuss published literature in this blog which are referenced with links.

 

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