When defects become an advantage

Our ancestors in Africa had genes producing dark pigments in our skins. These dark pigments protect us from the scorch of the sun. When some of them migrated out of Africa and into the cold and cloudy places, these people couldn't get enough sunshine and most of them perished. But some of them had a defect in their genes producing dark pigments. These people had lighter skins that enable them to absorb more of the scarce sunlight. Their defect in dark pigment producing genes turns out to be an advantage in the cold environment. 

Some people couldn't digest raw vegetables. Their defects in digestive systems force them to rely on cooked foods. With foods cooked and hence predigested, their digestive systems are less energy intensive. As a result, more resources are channeled toward brain. On average, these people have high IQ, which enables them to perform well in intellectual activities. This becomes an advantage in an environment requiring high intelligence. 

Autism is regarded as a disease in modern days. Being autistic largely insulates oneself from the prevailing social opinion. Many great scientists probably are autistic according to modern standard. Being autistic, one's original ideas can germinate, grow and bear fruits without yielding to external social pressures. In a society tolerant of independent ideas, being autistic can be an advantage. It is no accident that being autistic is defined a disease and independent ideas are actively suppressed occur around the same period of time.  

When we have a defect, don't be discouraged. We might create or seek an environment where this defect will become an advantage. When we have a loved one with a defect, we might create a micro environment that turn this defect into an advantage.