American scientists have revealed that reproduction and lifespan are genetically associated but in a negative way.
- People with genetic mutations linked to having children earlier in life are more likely to die before age 76.
- These genetic mutations could also lead to diseases later in life.
- Compared to environmental factors, genetic factors play a minor role in changes caused by natural selection.
Genetic mutations that favor reproduction tend to shorten lifespan. This was recently revealed by researchers at the University of Michigan (United States). Before reaching this conclusion, they wanted to test biologist George Williams’ theory, known as “antagonistic pleiotropy.” According to the specialist, natural selection favoring genetic mutations, which confer earlier or more abundant reproduction but alter post-reproductive life, is at the origin of aging. To test this hypothesis, the team used genetic, reproductive and death data from 276,406 participants from the UK’s Biobank database in a study.
Reproduction: less chance of living long due to genetic mutations
According to the results, published in the journal Science Advances, a strong negative genetic correlation was observed between reproductive traits and lifespan. The authors found that people genetically predisposed to having children earlier were less likely to live to age 76. However, scientists have warned that reproduction and lifespan are affected by both genetic and environmental factors. In the work, genes played a relatively minor role compared to contraception and abortion.
“Natural selection doesn’t care much about lifespan after reproduction ends”
“These results confirm the theory of George Williams. (…) Natural selection does not care much about the length of life after the end of reproduction, because our physical condition depends largely on the end of reproduction”, said Jianzhi Zhang, co-author of the work, in a statement. He added that certain reproductive-enhancing genetic mutations could lead to pathologies later in life. “One of these variants, called rs12203592, for example, has been associated with certain cancers,” concluded the researcher.
