A new study suggests that our bodies might increase these investments to slow the pace of aging if our father or grandfather waited until they were older before having children.
“If your father and grandfather were able to live and reproduce at a later age, this might predict that you yourself live in an environment that is somewhat similar — an environment with less accidental deaths or in which men are only able to find a partner at later ages,” said Dan T.A. Eisenberg, lead author of the study published June 11 in the Proceedings of the National Academy of Sciences.
“In such an environment, investing more in a body capable of reaching these late ages could be an adaptive strategy from an evolutionary perspective,” he said.
Eisenberg will become an acting assistant professor in the University of Washington’s anthropology department this fall. He did the study while at Northwestern University.
The study, which was conducted in the Philippines, found that children of older fathers not only inherit longer telomeres, which are DNA found at the ends of chromosomes, but that the association of paternal age with offspring telomere length is cumulative across multiple generations. Shorter telomeres seem to be a cause of ill health that occurs with aging — longer telomeres seem to promote slower aging.
It appears that as men delay reproduction, they will pass on longer telomeres to offspring, which may facilitate extension of life span and allow reproducing at older ages.
Eisenberg said he hopes the study will further the understanding of the evolution of aging, why we get old and the ways that we adapt to the environment.
“When we think of adaptation, we tend to think of it happening over hundreds of generations,” Eisenberg said. “This study illustrates a means by which much more rapid adaptive genetic changes might occur over just a few generations.”
He and his co-authors said their study should not be taken as a recommendation that men reproduce at later ages, because previous research has shown that older fathers are more likely to pass along harmful mutations to their offspring at conception. This can lead to increased rates of miscarriage and other health issues in offspring.
The National Science Foundation, Wenner-Gren Foundation and National Institutes of Health funded the study. Co-authors are M. Geoffrey Hayes, and Christopher W. Kuzawa of Northwestern.
For more information, contact Eisenberg at firstname.lastname@example.org or 847-859-9179.
This story is adapted from a news release by Hilary Hurd Anyaso at Northwestern University.