Rob Dunn of the Smithsonian highlights ten human imperfections as evidence that we evolved. “From hiccups to wisdom teeth, the evolution of homo sapiens has left behind some glaring, yet innately human, imperfections.” What human features made the list?
1. The fact that mitochondria became the prey for our cells.
2. Hiccups. The original function? Our ancestors who were fish and early amphibians “pushed water past their gills while simultaneously pushing the glottis down.”
3. Backaches. Learning how to stand up gave us the ability to see farther, and it gave us freedom to make better use of our hands. But the resulting “S” shaped back is not a good design for supporting our considerable weight.
4. Unsupported intestines. Standing up made them hang down “instead of being cradled by our stomach muscles.” this often leads to hernias.
5. Choking. In most animals, the esophagus is below the trachea. This allows us to speak, but allow falling food and water “about a 50-50 chance of falling in the wrong tube.”
6. We’re cold in the winter. We lost our fur, and this proves that evolution is blind as to where we will end up.
7. Goosebumps. They are good for making our fur stand up when we look bigger to scare away a potential predator. But See #6: we lost our fur.
8. Our brains squeeze our teeth. Bigger brains left less room for big jaws. I’m not convinced that the big brain came first, however. I’ve read accounts that suggest that fire lead to less need for big jaws to chew uncooked food, which lead to more room for the brain.
9. Obesity. Those strong cravings for sugar, salt and fat were great when we lived on the savanna, where these things are scarce. In our current food-rich environment, these ancient cravings are toxic for most of us.
10. Rob Dunn makes this the miscellaneous category. He includes male nipples, blind spots in our eyes, and our coccyx (a bone that used to be our tail).
I think that a diet rich of carbohydrates was not part of the 'evolutionary normal' environment (as in Environment of Evolutionary Adaptedness) and constitutes a massive change of environment for humans.
All sorts of illnesses ("lifestyle diseases") are what follow:
– Deteriorating tissue quality over the life-span (Coronary diseases, decay of muscle tissue, artrose even back aches), because the daily change from glucose- to protein-metabolism.
– The range of obesity (which is a symptom, not a root cause) and diabetes problems.
– All sorts of stomach related problems (Crohn's disease to name only one)
– The so called nutritional deficiencies and its set of problems
– All sorts of problems related to the endocrine system (Gland insufficiencies, failure of glands, overproduction of glands, adenomas and carcinomas of the glands)
– Possibly some of the other forms of cancer as well
Thanks, Tony. Good point that calories are now cheap and easy, leading to all kinds of medical issues. Those numerous medical issues that appear when we jam in those refined flours and sugars illustrate that we are evolving on a methodical clock that can't be hurried along.
And lest I forget: There is wonderful evidence that humans evolved in this changed environment and developed some sort of "improvements", like a more "stable" pancreas (lower diabtes type 1 rate in southern Europe than in northern Europe, were agriculture arrived later). Something similar to the development of the lactose-tolerance.
Either that, or that we were haphazardly thrown together by a creator that cared very little for where we were or where we would end up.
But even that imperfect design was perfect. We just don't understand it, having the imperfect puny human brains that we have.
😀
Or we were created by a being that was not all that good at creating living things. Perhaps we were created by a tinkerer. But that's what evolution IS: a tinkerer. Breed and weed.
No, I think roughly 10.000 years since the neolithic revolution (with its environment-change: increased carb content in the food) was not enough time for a complete adaption to the new environment. (And take a look at the massive decrease of life expectancy that coincided with the neolithic revolution, to see what impact carbs had). There were some adapations – Evolution had some time to iron out the worst bugs, so to speak – but we would need another 100.000 to 200.000 years of evolution to adapt fully. In the mean time people would need to suffer and die, this would some kind of Social-Darwinism, something I am not willing to accept.
Then of course since the industrial revolution the quantity and quality of carbs massively increased and we can see an increase an coinciding increase in "lifestyle diseases".
I think we need to change our diet as humans, cut out most of the carbs and find ways to produce enough proteins to feed the world.
Tony mentioned nutritional deficiencies. One I've always found interesting is the inability of humans (and a *very* few other species) to synthesize Vitamin C within our bodies. Interesting that dogs (for example) can make their own Vitamin C from the foods they eat, while we "intelligently designed" humans cannot.
Grumpy: The vitamin C issue is a compelling point featured by Kenneth Miller in his book, Only a Theory. http://dangerousintersection.org/2009/04/13/kenne…
Here are seven more evolutionary leftovers. http://www.divinecaroline.com/22178/67814-seven-e…
Seems that inability to synthesize Vitamin C is a trait which makes us stand out among species. Seems to me that if one were to say we were designed, we should stand out among species, and that inability could be simply there to allow us to enjoy those things that give us the vitamin C. A dog needs not seek the oranges to enjoy, we may unfortunately have sought the wrong apple.
Kyle: Evolution doesn’t plan ahead. It is a “tinkerer,” a process of breed and weed. Nor is evolution a persona concerned with what we might enjoy (and I don’t think it’s vitamin C that makes it enjoyable, though I have read of studies where people go to great lengths to seek out the only source of vitamin c on an island merely on the basis of craving for that food).