Over millions of years, creatures have evolved many complex adaptations. However, we are still vulnerable to many diseases. Among these tragic ills and the most puzzling is cancer. Cancer cells are very well adapted to their environment. In fact, scientists have always wondered how cancer cells are able to survive in very harsh environments? Even with the use of strong chemicals such as Chemotherapy, somehow the cancerous cells are still able to survive, multiply and grow. Until, scientists made a revelation discovery, which led them to believe that the secret to this adaptation lies within the evolutionary process itself. First, the evolution process is very crucial as it’s responsible for the biodiversity at every level of biological organization, including species, individual organisms, and even molecules. This powerful mechanism was essential for the evolution of multi-cellular organisms and became more vital as animals evolved larger bodies and longer lives. Moreover, the evolutionary process was guided by natural selection, which is a process that favors certain traits whereby organisms adapt to their environment and tend to survive and produce more offspring. This theory was first fully explained by a scientist named Charles Darwin. He proposed that all creatures on earth have evolved from one single-celled organism. This single-celled organism started to evolve because of natural selection. These organisms induced mutations because of natural selection and were then able to mutate and evolve to become specialized cells. These specialized cells then created tissues, organs, and organ systems. Until the first animals showed up on earth about 700 million years ago. Then the evolution process continued until we finally became humans. However, this remarkable achievement that was caused by evolution had many downsides. But, the most tragic and devastating downside is cancer. In the past researchers, hypothesized that cancer was caused by carcinogens, such as smoking. The theory was that a carcinogen, such as a cigarette smoke, induced mutations in a cell’s DNA that eventually caused it to become cancerous, which multiplied and then spread. However, it turned out that smoking doesn’t cause mutations. Rather It alters the genes themselves, smoking changes the activity of genes through a collection of processes called epigenetics. Epigenetics consists of tiny modifications either to the DNA itself or to proteins called histones that wrap around the DNA and change the activity of the genes. Cancerous cells are well adapted for survival, that’s because they can easily manipulate the body and steal more nutrients from surrounding tissues and cells. Thus, killing and damaging surrounding tissues and organs. Not only that, but the cancer cells continue to divide and grow long after ordinary cells would stop, which makes them unstoppable. They destroy surrounding tissues to make room for themselves, and they trick the body into supplying them with energy to grow even larger. Moreover, the ability of these cells to adapt so fast has puzzled scientists for many years and have led them to think that the cancer cells are theoretically immortal. But only recently did scientists discover the link between the Evolution and cancer. This discovery can potentially hold the key to curing cancer. Scientists discovered that the cancer’s development within an individual is also an evolutionary process. In the same way that species evolve by mutation and selection acting on individuals in a population (Natural selection), tumors also evolve by mutation and selection acting on cells in a tissue. This causes the cancer cells to evolve very rapidly and gain a lot of diversity. In fact, researchers say that there aren’t two cells in the same tumor that is the same. Therefore, even with the presence of strong therapies that can decimate a cancer cell population, it’s still not able to eliminate cancer. Unfortunately, since cancer cells are very diverse and evolve very rapidly, can also evolve resistance to these therapies. Therefore, scientists are in constant demand for developing better and newer treatments to kill this dreaded disease. In addition, scientists have wondered if natural selection was powerful enough to create complex adaptations, from the eye to the brain, and the immune system, then why has it been able to eliminate cancer, once and for all? The evolutionary process has always favored certain traits that would help us better survive in the future. For example, it has favored certain defenses against cancer but cannot eliminate it altogether. Based on the study done by Doctor Norman E. Sharpless of the University of North Carolina at Chapel Hill, which studied the effects of the P16 gene that was favored by natural selection to defend us against cancer. He and his colleagues have experimented on genetically engineered mice that lacked the p16 protein. At the end of their research, they concluded Natural selection favors anticancer proteins such as p16, but only in moderation. If these proteins become too aggressive, they can create their own threats to health by making bodies age too quickly. As a result, natural selection couldn’t eliminate cancer. In conclusion, by studying cancer from an evolutionary perspective scientist can better understand why cancers predominantly occur in the elderly? Ans how does exposure to conditions such as radiation and smoking, are associated with increased cancers? Most importantly, the application of evolutionary theory to cancer should create new treatments which could better control this dreaded disease.