Biological Immortality

Biological immortality is the absence of a sustained increase in rate of mortality based on chronological age. A cell or organism that does not experience aging, or ceases to age at some point, is biologically immortal. Life defined as biologically immortal is still susceptible to causes of death besides aging, including disease and trauma. Biological Immortality is not just a concept, but has been demonstrated by a few species on earth:

• Turritopsis nutricula — a species of jellyfish. After becoming a sexually mature adult, they transform back into a child (the polyp stage) via the cell conversion process of transdifferentiation. This process repeats indefinitely. Its immortal adaptation has allowed it to spread from its original habitat in the Caribbean to "all over the world."

• Bacteria (as a colony) — Bacteria reproduce through cell division. A parent bacterium splits itself into two identical daughter cells. These daughter cells then split themselves in half. This process repeats, thus making the bacterium colony essentially immortal.

• Hydra — a freshwater animal, considered biologically immortal as they do not undergo senescence or aging. Hydras are predatory animals that can be found in most unpolluted freshwater ponds, lakes and streams in the temperate and tropical regions.

• Bristlecone Pines — a pine tree species speculated to be potentially immortal; the oldest known living specimen is 4,789 years old. Even longer lived are "tree colonies" which are genetically identical trees that are all a part of a single living organism with an enormous underground root system. A group of 47,000 Quaking Aspen clones (nicknamed "Pando") in Utah is estimated to be about 80,000 years old. A colony of sea grass, Posidonia oceanica, in the Mediterranean Sea, could be up to 100,000 years of age