Monday, 18 February 2013

Evolution to be blamed for bad backs, tooth aches: Scientists

Evolution may have put humans at the top of the food chain but it also landed us with bad backs, dropped arches and impacted wisdom teeth, scientists have claimed.

While the process of natural selection allowed humans to become much more advanced than other primates, it is also to blame for many of the maladies we suffer from today.

For all our success as a species, the problems we still experience as a result of our evolution demonstrates that humans are in fact "not very well designed", researchers explained.

Our development of large and complex brains, for example, resulted in a narrowing of our mouths which in turn caused the pain of impacted wisdom teeth.

Similarly, when our ancestors began walking on two feet six or seven million years ago, they prompted skeletal changes which today result in bad backs.

Our spines were originally arch-shaped, but standing upright turned the backbone into a weight-bearing pillar, causing the development of the "S" shaped curves which help us balance and walk but also cause lower back pain.

Studies suggest that conditions like flat footedness and high ankle sprains, which are often attributed to our modern, inactive lifestyle, were in fact plaguing our ancestors as many of 3.5 million years ago, the Telegraph reported.

Prof Jeremy DeSilva of Boston University said that our feet would be much more effective if they resembled the "blades" used by paraplegic runners, rather than consisting of 26 individual moving parts.

Impacted wisdom teeth can be blamed on our development of large brains, which caused the shape of our skulls to change and shortened our mouths leaving no room for a third molar, Prof Alan Mann added.

Many people now carry genetic mutations which mean they no longer develop wisdom teeth, with 25 percent of people now lacking at least one third molar.

Although lacking wisdom teeth does not provide a survival advantage in the modern world,

Prof Mann suggested that the trait may one day die out because people with aching jaws might be marginally less likely to have children.

He said that one plausible scenario might be that one evening, a partner in a relationship suggests a bout of reproduction, and the other partner, plagued by an impacted third molar which is painful enough to be distracting, says: "not tonight dear, my jaw is killing me."

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