Getting older may come with more aches and pains, but new research suggests there’s a bigger picture to look at: As we reach our old age, we might actually be helping the evolution of our species .
Aging was once assumed to be an inevitable consequence of living in a hectic world, but is now considered something of a mystery . Some species barely age, for example. One of the big questions is whether aging is simply a byproduct of biology or something that comes with an evolutionary advantage .
The new research is based on a computer model developed by a team at the HUN-REN Ecological Research Center in Hungary that suggests old age can be positively selected in the same way as other traits.
The research has been published in BMC Biology .
In recent years, scientists have investigated the inevitability of aging and associated deterioration of the body (technically known as senescence ). What the model suggests is that, in certain situations, it can be beneficial for a species.
"Aging can have an evolutionary function if there is selection for senescence," says evolutionary biologist Eörs Szathmáry from the HUN-REN Ecological Research Center. "Our goal was to discover this selection."
These situations require strong directional selection , where evolutionary pressures (such as predators or environmental change) guide traits in a consistent direction; and significant kin selection, where genes have a greater chance of being passed on through the help of relatives.
"For example, it is possible that in a changing environment, aging and death are more advantageous for individuals, because in this way competition, which makes it difficult for the most adaptable progeny with better genetic compositions to survive and reproduce, can be reduced. " says Szathmáry. In other words, natural aging and death leave room for a new generation that could have better combinations of genes.
The researchers also suggest that kin selection would favor more generations remaining through prolonged senescence in organisms that are strongly altruistic. In other words, those who help their relatives create a new generation more often pass on their long-aging genes through them.
While humans as a species may be obsessed with stopping aging, it appears that senescence has an important role to play in terms of evolutionary advantage. – a role that experts are still trying to explore and understand.
"In the evolutionary biology community it has been accepted that classical non-adaptive theories of aging cannot explain all aging patterns in nature, which means that the explanation of aging has once again become an open question," says Szathmáry.
Conclusions We find that aging can be positively selected in a spatially explicit population model when sufficiently strong directional and kin selection prevails, even if reproduction is sexual. The view that there is a conceptual link between abandoning clonal reproduction and developing an aging genotype is supported by computational results. |
