June 12, 2012

Older Reproducing Males Have Longer Living Children

Connie K. Ho for redOrbit.com

With food items like cheese and wine, it´s thought that a longer time of preparation will give it a better taste. This idea of age affecting quality was highlighted in a new study by Northwestern University scientists. A recent study by researchers at Northwestern University found that people whose fathers and grandfathers waited until they were older to have children tended to have a higher amount of resources for the body to repair cells and tissues.

Based on the findings, the investigators propose that the slow rate of aging can cause the body to utilize more resources to keep up the maintenance of the body for a longer period of time.

"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," explained ead author Dan T.A. Eisenberg, a doctoral candidate in anthropology at Northwestern, in a prepared statement. "In such an environment, investing more in a body capable of reaching these late ages could be an adaptive strategy from an evolutionary perspective."

The researchers believe that the findings are incredibly fascinating.

"If our recent ancestors waited until later in adulthood before they reproduced, perhaps for cultural reasons, it would make sense for our bodies to prepare for something similar by investing the extra resources necessary to maintain healthy functioning at more advanced ages," noted co-author Christopher W. Kuzawa, the associate professor of anthropology at Northwestern and a faculty fellow at the school´s Institute for Policy Research, in a statement.

The project was conducted in the Philippines and researchers discovered that participants of older fathers inherited longer telomeres, which are DNA at the end of chromosomes. This connection between paternal age and the length of telomeres for offspring was seen in the data of many generations of family members. The scientists concluded that people with shorter telomeres tended to have bad health, while those with longer telomeres seemed to have slower aging. As such, men who delay reproducing will pass on longer telomeres and help their offspring have a longer lifespan.

Researchers hope to better understand why people age, how elderly members can adapt with the environment, and what affects the evolution of aging. Even though the findings are of interest to the group, they state that other men should not take the study´s findings as a recommendation to reproduce at an older age as past research has shown that older males have a greater chance of passing on harmful mutations to their offspring.

"When we think of adaptation, we tend to think of it happening over hundreds of generations," remarked Eisenberg in the statement. "This study illustrates a means by which much more rapid adaptive genetic changes might occur over just a few generations."

The scientists hope to replicate the results of the study in other populations.

"We will want to see if the longer telomeres that offspring of older fathers and grandfathers inherit at birth have fewer health problems and ailments as they age," Kuzawa said. "Based upon our findings, we predict that this will be the case, but this is a question to be addressed in future studies."