Dying makes sense from an evolutionary perspective because it clears the way for the next generation, which may then be better adapted to changing environmental conditions. Life expectancy varies tremendously among the different species on Earth. The record-holder is probably a giant sponge in the Antarctic, believed to be 10,000 years old. Single-celled creatures such as the Paramecium protozoa could even be considered immortal, as they can go on dividing indefinitely.
Humans do not have an inherent natural lifespan. This plasticity in human longevity was identified by James W. Vaupel, founding director of the Max Planck Institute for Demographic Research in Rostock. The life expectancy of people in industrialised nations has been increasing for almost 200 years – by around 2.5 years every decade. Reasons for this include advances in hygiene and medical care. If the trend continues, every second child born this year could live to be 100 or older.
On that basis, immortality is possible in principle. A prerequisite for that, however, would be finding out why people age. Aging is a kind of self-destruction mechanism: cell defence systems stop working; repairs are no longer carried out; cells divide less frequently. People continue to age until, ultimately, they die.
Despite the many advances that age research has made, we still cannot fully explain why we age. We need to look at internal factors, such as an organism’s genetic make-up, and at external factors, such as diet and physical activity.
We should remember that while death is a tragedy for us humans, it is also a part of life. If that were to change in the future, it would completely revolutionise the way we view the world and ourselves.
Dr Susann Beetz of the Ideas 2020 team answered this question.