What are the types of longevity

Long-lived species escape the aging process no better than short-lived ones


am by twiedenhoefer.

Max Planck researcher calls for a redefinition of aging.

Master of aging man

Because some living things live long, it was previously believed that they hardly age physically. How else could they have resisted death for so long? This logic is wrong, as Annette Baudisch from Max Planck Institute for Demographic Research (MPIDR) in Rostock now proven with biological data. In fact, long-lived species sometimes degrade much more than other species that die earlier. Baudisch therefore calls for a new definition of aging with two dimensions: the “speed” of aging, which reflects life expectancy, and its “form”, which states how the body's ability to survive increases or decreases over time.

Using ten sample species, Annette Baudisch describes in the journal "Methods in Ecology and Evolution" where the conventional concept of aging fails: Modern humans have the highest life expectancy of the ten species (around 70 years remaining from sexual maturity) and the robin the lowest (1.7 years remaining). Classically speaking, birds age much more than humans. It turns out, however, that the animal experiences a much weaker physical decline: while the robin stays in better shape until death than all the other species on the list, humans list them as "aging masters".

Humans age 1000 times more than robins
The difference is immense: "Modern people age more than 1000 times more physically than robins," says Annette Baudisch. The researcher succeeded in calculating this by giving the shape of aging a mathematical value: the more mortality, i.e. the risk of dying in a certain year of life, increases over time, the steeper its curve - and thus the shape of the Aging. In humans, the risk of death increases from sexual maturity to reaching life expectancy by a factor of 2000 - in robins by a factor of only 1.2. With Baudisch's new definition, the contradiction to the short-lived nature of birds no longer applies: robins age at a rapid pace because their life is short. Their aging process, however, takes the form of a curve that rises only gently. With humans, on the other hand, the pace is slow because they live long. However, the shape corresponds to a curve that points steeply in the direction of increasing degeneration.

The fact that people still get much older than robins is because their risk of death is much lower at any age. But in adulthood your body noticeably loses the ability to regenerate quickly enough not to degrade. The maintenance of robins works much better. In any case, good enough not to lose any noticeable chances of survival over their short life. Some species have amazing regeneration skills. This is how the Mexican tailed amphibian axolotl, which swims through water in the form of a baby throughout its life, allows organs to grow back completely. He can also regenerate his brain if necessary. The California gopher tortoise, like alligators and crocodiles, has a decreasing risk of death until it dies. For species such as roe deer, red deer or marmots, the risk of death decreases for at least some time after sexual maturity. And some birds like the mute swan, the fulmar, or the barn owl can at least keep the decay to zero during this time.

Why species live and die so differently is an unsolved mystery to science. “In order to discover the invisible law of aging, we have to explain what role it plays in the evolution of different species,” says Annette Baudisch. The biologist and mathematician is working on a unified, evolutionary theory of aging. The basic idea: How an organism ages depends on how much energy it invests in its own survival in the course of life - through growth, maintenance or repair of the body - or in the preservation of species through reproduction. "Living beings that, like humans, care intensely for their offspring could be candidates for severe aging," says Annette Baudisch. Because the energy that they invest in their offspring is missing to repair the physical decline.

Learning as a means against death?
"The fact that the risk of death decreases with age could also have social causes or be due to learning success," says the MPIDR researcher. For example, it could be that some animals increase their chances of survival over time because they learn to hunt better or to avoid predators. The influence of growth is certain, as the example of crocodiles shows: Their mortality falls with age because they do not stop growing: If they have not been eaten by larger conspecifics beforehand, they become the largest themselves - and are no longer in danger of death .

About the MPIDR
The Max Planck Institute for Demographic Research (MPIDR) studies the structure and dynamics of populations. From politically relevant topics of demographic change such as aging, birth behavior or the distribution of working hours over the life cycle to evolutionary biological and medical aspects of aging. The MPIDR is one of the largest demographic research institutions in Europe and is one of the top international institutes in this discipline. It belongs to the Max Planck Society, the world's most renowned research association.

Contact Person
Annette Baudisch (author of the article)
Phone: 0381/2081 - 259
email: [email protected]