The research that first led me to question scientific dogma took place in the petri dishes that are the workhorses of cell biologists' laboratories when I was cloning stem cells. Stem cells are embryonic cells that replace the hundreds of billions of cells we lose daily in normal attrition due to age, wear-and-tear, etc. As hundreds of billions of cells die every day, hundreds of billions of new cells are created from our bodies' stem cell population.
For my experiments, I would take one stem cell and put it in a petri dish all by itself. That cell would then divide every ten to twelve hours. After a period of about a week, I’d have about 50,000 cells in the petri dish. For my experiments, the most important factor was that all of the cells were genetically identical because all of them came from the same parent cell. Then I split up the cell population into three dishes, each with different culture mediums, i.e. each with a different environment. Despite the fact that all the cells were genetically identical, in environment A, the cells formed muscle; in environment B, the cells formed bone; and in the third environment C, the cells formed fat cells.