A decade ago, an Indian boy was born with a tail. Yes, like how a monkey has! Scientist believes this is due to lack of a gene, which basically informs the body to not grow a tail. After all, all of our ancestors had tail in the past, per Darwin’s theory.
Since we all have evolved a LOT from a single cellular organism, we still have the features of ALL the intermediary transitions hidden in a gene. Meaning, the blueprint is there, but there are instructions NOT to execute it! This fact is really just mind-blowing! And, this is the basis for a disease that we humans call “Cancer”.
Cancer is a phenomenon, where in, the cells forms a cluster, which does not obey normal rules of a multi-cellular organism, and keeps growing at it’s own pace, and spreads across body to cause more damage, eventually killing the person.
Until 70s, we believed that Cancer were caused by tumors, (bunch of bad cells), which has to be removed by Chemotherapy (Poisoning), Radiation (Heat), or by Surgery (Opening). But, the answer to why this tumor was caused was beyond the scope of the time!
70’s to 2k, it was believed that Cancer was caused by “Somatic Mutation” of cells: where in a normal cell genetically mutates to become cancer. They also theorized that it would have to take several millions of mutations, for a normal cell to become a cancer cell. The answer to why does it genetically mutate was not answered.
After 2000’s seem to be a new dawn for Cancer research. As primates, all humans have evolved from unicellular organism. The way in which unicellular organism grows, and works to survive is exactly opposite to how a multi-cellular organism grows, and works.
While unicellular could be compared to a person living in the woods, who has his own rules, and who does everything on his own; multi-cellular is like people living in cities; There is a State and rules have to be followed. And, that is the actual reason for our existence, the cells in the Liver knows that it cannot grow bigger than a certain point, etc., which are basically controlled by set of hormones and a bunch of other things;
However a uni-cellular’s only goal is to keep growing and survive; If it can’t it dies.
Every cell in our body has the potential to mutate from a multi-cellular organism to a uni-cellular organism (Atavism); And, when a cell becomes and shows the attributes of uni-cellular organism, it is termed Cancer.
These cells keep growing at it’s own pace, it progresses, and also moves to multiple other locations in the body to survive (metastasis) and spread.
Why does this happen? Because of a process called carcinogenesis. If the cells are overly exposed to bad things, they are destroyed. If the bad-things are weak, then our immune system fights it off. Carcinogenesis is something in between; The cells are in a state where they are not fully destroyed, and cannot fully survive, and that is when “out-of-the’-survival” need for the cell, it becomes/behaves as a single-cell organism. Which is Cancer!
This usually does not happen on a single once-in a life-time event, but a very gradual manner, and repeated exposure of bad-things increases the chances of a cell to become cancer. This is the seed for cancer to start!
Mind that this could also happen under many other circumstances. For e.g., the acid-reflux that we get after eating food, can be withstood until the top of stomach, but when it moves to the oesophagus, then it’s toxic there, and on repeated exposure of the same, there is a chance of the cells mutating to it’s ancestors, eventually causing cancer!
These seeds are only half the equation; unless it has good soil to grow, they could not end up being fatal.
While exposure to carcinogens, and several factors cause Cancer cells, obesity, and food habits act as a soil for the cancer to grow easily.