Humans are ever changing, adapting to the environment around us in numerous ways. One of these ways is through biological evolution allowing humans to drink milk. Every mammal is used to breastfeeding, or having some milk supplementation as an infant, but not every mammal continues drinking milk throughout the rest of their life. We are the only mammal that drinks milk past breastfeeding, due to evolving genes that allow our bodies to process lactose and break it down. This started when those of European descent started dairy farming, meaning people in that area were exposed to milk more. With the increased intake of milk people in that area were more able to process the lactose in milk, shown by only 5% of people from European descent being lactose intolerant. Comparing this to those of East Asian descent with 95% of that population having an intolerance to lactose. Nowadays, we think of drinking milk as a normal part of life, being encouraged to drink it due to being high in calcium. I find this interesting because even though we have evolved to be able to drink milk, in present day more and more people are becoming lactose intolerant. Is evolution progressing the other way, making us unable to process lactose after evolving to be able to process it thousands of years ago?
Another way that humans are continuing to evolve is shown is what the causes of death are past versus present. Modern medicine has allowed evolution to progress in terms of disease present in society and the way we treat these diseases. Over time we see different diseases present and therefore different causes of death. Even 100 years ago the leading cause of death was primarily due to infectious diseases, such as pneumonia, influenza, tuberculosis, or diphtheria. Now, we have vaccinations that help prevent many infectious diseases, as well as treatment options that effectively treat these diseases if contracted. Although we have improved healthcare significantly since even 100 years ago, other causes of death have increased due to increased lifespan. In present day we see more deaths due to cancers and heart attacks or strokes because people are living longer due to reduction of infectious diseases. These causes of death were not previously seen because people were not living as long and these diseases were not able to develop in the body. In conjunction with diseases now present, more people suffer from diabetes and obesity which is likely due to the evolution of food and the increased quantity of processed foods. Due to the lifestyle changes, health concerns based on how we live are more prevalent. Another modern medicine breakthrough is genetic modification of crops to increase crop yield and provide resistance to pests. Through genetic modification shelf life can be increased and nutritional value can be improved. An example of this genetically modified corn that contains a gene that kills larval pests, reducing consumption and death of plants. Gene therapy is also being designed to help genetically change mutations to fix these mutations prior to a disease forming. Although controversial, gene therapy could revolutionize modern medicine and allow a fix for mutations that previously could not be cured.
Hi Madison! I also talked heavily about how we variability of the way we do things in modern society than in the past. I really enjoyed when you talked about the death process. What occurred in the past versus the present. That too can be a major factor to why the effective use of creating new medicine is what expands our health. Back then, life expectancy was short in comparison to now. We have evolved to have more and more intelligence when it comes to health to expand the life expectancy in humans today. Now that I know that diseases have caused more of an impact than I expected today. The genetics we inherit from our ancestors affects our body. However, I like how you reference gene therapy as a way to show the evolution of modern medicine to help the mutations that are occurring.
Joshua K. Belcher
Hi Madison,
Wow, what a great, and specific example with milk and how it came about and introduced to humans’ lives and environment. I have heard that European descent are rare to have an intolerance, and more Asians have an intolerance. I am Asian American myself, and I have developed a lactose intolerance as I grew up. Nowadays we may hear people avoiding dairy due to it being “trendy” or dairy is just not making them feel good or ruins their skin. There are many reason behind it, but maybe it is not JUST due to developing or having a lactose intolerance. That is still interesting though, maybe we just did not hear of this “problem” in the past because it was not a big deal to be vegan, dairy-free, vegetarian, etc. as it is right now due to the increasing temperatures of the planet and what people decide to do to their diets in hopes of saving the environment. That is what I focused on in your post, but otherwise the rest is extremely reflective and interesting. Good post!
I think its really interesting that you used such a specific example of how we drink milk. I didn’t really think about it but its interesting to know we are the only species that drinks milk for other purposes besides breastfeeding. I think its also a pretty huge debate that we shouldn’t even be drinking milk in the first place, it hasn’t been passed down to us and I don’t believe there was anyone in the past that decided to drink from a cows utters so this is really interesting to learn how we are the only species doing this for other purposes. Its evident that there are other species to survive without the use of this dairy product as part of a nutritional meal.
Hi! I loved your post. I think the idea of humans evolving to be able to drink milk is so interesting. The fact that milk is part of our everyday lives and it’s in most of the things we eat or drink blows my mind because we had to evolve to be able to make this part of our lives. When I was younger I never put much thought into what makes someone lactose intolerant but as I got older I found it so interesting that so many people are lactose intolerant because we are actually not supposed to be consuming milk! It’s amazing that our bodies have been able to evolve to get us to a point where a majority of us can drink milk daily and not have any problems with it. It makes me wonder what other foods are in our diet that we historically were never meant to consume.
Hi Madison, great blog! I really was drawn into your blog by the beginning discussion on drinking milk. I have had the conversation and/or debate with people many times over whether it is good or bad for us human beings to be drinking cow’s milk due to the way that it is produced and the fact that it’s animal’s milk. The things you discussed in terms of that reminded of a documentary on Netflix called “What the Health.” The documentary seemed to argue that even though we’ve evolved to be able to consume cow’s milk, it’s weird that we are the only mammals to continue drinking any milk after infancy and doing so poses more so of a threat to our health. Personally, I wasn’t a milk drinker growing up and I’m still not today, but I think that it is possible that the current progression of evolution could be making people unable to process lactose; of course, in addition to all of the factors revolving around the dairy industry.