There is a species of jellyfish, called Turritopsis dohrnii, which is also known as the immortal jellyfish. These jellyfish begin their life as tiny, free-swimming larvae. As the larvae settle down, they give rise to a colony of polyps that are attached to the sea floor. Jellyfish then bud off these polyps and continue their life in a free-swimming form, eventually becoming sexually mature. If the T. dohrnii jellyfish is exposed to environmental stress, physical assault, or is sick or old, it can revert to the polyp stage, forming a new polyp colony. It does this through the cell development process of transdifferentiation, which alters the differentiated state of the cells and transforms them into new types of cells. Theoretically, this process can go on indefinitely, effectively rendering the jellyfish biologically immortal, although in practice individuals can still die due to predation or disease without reverting to the polyp form. The capability of biological immortality with no maximum lifespan makes the species an important target of basic research on aging.

So, what does this tell us? My takeaway is that there is no natural law that says we must age as we get older. It is possible, at least theoretically, for some natural process to reverse the course of aging and revert cells back to an earlier more youthful form. This is important to me for two reasons: 1) There may be a breakthrough in medical research that can mimic this process and effectively create a fountain of youth. If so, we want to live as long as possible waiting for this to occur so that we may benefit from it before we die. 2) Because it is scientifically proven that aging is not a given fact of life, we can change our mindset to how can we reverse the effects of aging on our bodies, not whether we can. Belief is a powerful force within our minds, and our minds exert a significant amount of control over the rest of our bodies. Belief that we can reverse aging is, in itself, an important first step. I have already made the mental shift to believing that it is biologically possible to halt or reverse the aging process, and that belief alone is already having effects, in my opinion.