Earlier this semester I talked about a few new kinds of assignments I was trying out in my evolutionary medicine class. I’ve got my students posting on the readings every week at the group blog, and there have been several great interactions. For instance, here is a thoughtful comment on one student’s post:
“…I have long wondered why a natural process, such as ovulation, is so painful and discomforting in a spectrum of ways to women across the board. Perhaps hormonal contraception modalities are not the ideal accommodation, but can you really blame the women who opt for it?
“I think perhaps it is our culture that is out of balance with our biology and needs a second review. Not only are women reaching ages of menarche earlier, experiencing higher levels of hormones, having fewer children to break the hormonal cycle, but our lifestyles just do not accommodate in alleviating this process. How are our stressful lifestyles adding to the premenstrual discomfort and feelings of inconvenience women have about their reproductive cycles?
“I understand that oral contraception stands in the way of natural ovulation and conception, but similarly, our culture stands in the way of our natural biological functioning. Should women have to live with discomfort and contemptuous feelings towards their bodies, supported by large cultural consensus that menses is ‘annoying so why not just stop it’? Is this ideology not also to be reproached?
“I only bring this up to suggest that perhaps the huge injustice to our bodies has been our cultural environment and not just the fix-its that we humans have come up with….”
You can check out the whole blog here.
But that’s not all! As part of their 20% projects, a few students have decided that the way they want to present their work is through writing a blog. First there’s The Daily Filling, a blog by a pre-dentistry student who is using her 20% time as a chance to integrate what we’re learning about evolutionary biology into a better understanding of dental health.
Here’s a neat passage from her post on sugar:
“I feel it is essential for readers to understand how humans have evolved to consume sugar more readily and how although it appears counter-intuitive that natural selection has not chosen against the side effects of sugar, it is not entirely Mother Nature's fault. Sugar had historically been a rare substance for our ancestors to obtain--when it was ingested, it was readily stored and then used. New York Times states "humans evolved to crave sugar" and that apart from honey, there was rarely any food sweeter than carrots.
“If only they tried a Twinkie or two.
“Natural Selection has indirectly favored this genetic predisposition of craving sugar as a means of survival and reproductive success. What limits modern day humans is the excessive consumption of refined sugar spread throughout the day instead of at one sitting.
“From a dentition standpoint, it thus makes sense why our early Hominid ancestors lacked any cavities or tooth decay. When agriculture was discovered, the lactic-acid causing bacteria Streptococcus was found in more mouths across the world--found from eating all sorts of foods from carbohydrates to milk sugar (lactose) and sucrose. And, because brushing one's teeth was a relatively novel idea at the time, the decay of teeth began.”
“So how does stress physiologically strain the cardiovascular system so much that it can give a perfectly healthy individual a heart attack?
“The obvious answer? – Stress. Though, it is far more complicated than that. From an evolutionary perspective, the stress response of our cardiovascular system is ideal. Say you are living 100,000 years ago. You and couple of your tribal peers go out hunting for a boar. You find one, have it in sight. You begin strategizing your method to catch it. But something unplanned happens – the boar starts charging you! Stress response activated: your digestive tract shuts down and your breathing rate surges. Your body inhibits the release of sex hormones, while others like epinephrine (adrenaline), norepinephrine and glucocorticoids spill into your bloodstream, activating the sympathetic nervous system. Heart rate increase to pump oxygen quicker throughout the body, glucose energy reserves are released, attention and response centers in the brain are heightened, and blood flow to skeletal muscles are top priority. With all this in place, you have a pretty good chance of escaping that charging boar intact.
“This heightened blood flow is well and great when we have the metabolic demand to match. However, like family member ‘A’, if these physiologic responses are chronic, you are continually diverting as much blood flow to your limbs, straining the heart and overlooking other areas of the body. This is when we see damaging effects.”
Finally, one of my students wanted to learn more about variety in the human diet by trying a number of diets herself (not the weight loss kind) for her blog Cuisine for Comfort. She has recently finished a rice-based diet and a typical Western diet – check out some of her daily posts that she has written, with pictures of her meals and descriptions of her health!
So go give these students a little love. They’re trying to make the blogosphere a little more sciencey, and are doing great work incorporating evolutionary medicine into their own interests, which is perfectly in line with the 20% project.