Evolution through Natural Selection is scientific fact. This is based on an enormous volume of evidence in the scientific database to date. Natural Selection occurs through the "passing on" of good genetic traits that benefit a species to survive. Good traits are essentially "passed on" to daughters and sons because they help them to survive and further pass on good traits. Bad traits, if passed on to progeny, will eventually die out (given enough time) because they offer a disadvantage to that species that eventually leads to their demise. When a species with a bad trait dies, so does the bad trait.
So how does this explain the fact that humans still have numerous genetic diseases present within our genome today? We would have thought that 2 million years of Evolution Through Natural Selection would have selectively removed all those diseases that posed a threat to our human existence.
One researcher has an intriguing theory and believes he can explain it. In his book, Survival of the Sickest, Sharone Moalem argues that Evolution Through Natural Selection has actually preserved certain diseases within the human genome because at some point back in Human history, these diseases actually provided a certain key benefit to our human ancestors that allowed them to survive hash climatic conditions, such as Ice Age or infectious plagues.
For example, he explains, the Bubonic Plague (a.k.a The Black Death) killed 25,000,000 people in Europe during the 1800s. To put this in perspective, this is approximately equivalent to the number of people killed during World War I and World War II COMBINED. The plague killed so many people because it was highly contagious, its cause was unknown and the way it was spread was also unknown.
The key to stopping the plague was not due to some revolutionary cure discovered by a brilliant physician, but to our remarkably resilient human genome. As it was discovered many years later that certain people actually survived the plague. It was through the study of those survivors that it was discovered some people had the necessary genes to stop the plague in its tracks. Therefore the human genome through Natural Selection, developed the key to stopping the plague.
The Bubonic Plague, was a bacteria that thrived on iron. After entering the body, the immune system would send out its white blood cells to consume the invader. However, the plague cells would use the iron of the white blood cells to grow and multiply. Acting like a “Trojan Horse” these cells would ultimately spread to other cells and be carried to other parts of the body, within the white blood cells (particularly the lymphatic system) spreading. This remarkable adaptation of the Bubonic Plague cells was extremely efficient, killing approximately 60% of all those infected in four days if untreated.
Iron is abundant in the cells of a normal human being, and this is why the Bubonic Plague was so effective. It would use the body’s own iron-rich immune system against it. However, the plague cells did not do well in iron-poor conditions.
Hemochromatosis is a genetic disorder (although not always genetic) that comes from the accumulation of iron in the body. In this disease, iron enters the body through food we eat, but continues to build up instead of being removed after the body has used all it can. The result is essentially “Iron Poisoning”.
As it turns out, people with Hemochromatosis do not have high Iron in all cells of their bodies. Unlike healthy people, white blood cells of their immune system are actually “IRON POOR”. So you see, this genetic trait of the disease actually makes them ideally suited to fight the Iron-seeking Bubonic Plague Bacteria.
As the plague bacteria entered the body of a person with Hemochromatosis, the White blood cells would attack and ingest the bacteria. However, as the white blood cells are devoid of Iron, the Bubonic Plague Bacteria had no way of surviving and multiplying. Therefore, it was stopped in its track.
This was one of the main keys in halting the Bubonic Plague which devastated Europe in the 1400s. The human genome, through Natural Selection, had developed a specific beneficial trait against a specific intruder bacterium to end the most devastating plague in human history. This benefit (although an iron accumulating disease) was passed on to future generations because they survived the plague to pass it on.
This is an intriguing book, describing an intriguing theory and has numerous other examples and corroborating data that I will describe in future posts. I highly recommend reading it.
Maddalena Environmental Inc.