The same genes responsible for children's growth and development are responsible for their degeneration, assert Harvard researchers in a new report.
According to a press release on the report, scientists have long frowned on the idea that development is linked to aging.
In the new report, published in the journal Physiology, Joao Pedro de Magalhaes and George Church of Harvard Medical School argue that new evidence supports the theory that aging is driven by the same genetic processes behind development.
"We now know of several animals that can delay development and as a result delay aging as well," says de Magalhaes, the report's lead author. "Even in mammals there is growing evidence that aging is a consequence of developmental mechanisms. For instance, the pace of development influences the pace of aging, suggesting that the timing of developmental mechanisms determines the timing of aging in mammals."
The researchers do not think, however, that aging is an intentional product of evolution.
"I don't think aging is under strong selection," says de Magalhaes. "What happens, at least in higher organisms like mammals, is that evolution is not about selecting for long life. Evolution is about optimizing developmental mechanisms for reproduction. Once an organism has passed its genes to the next generation evolution gives up on it and the same genes responsible for the growth and maturation of that organism will inadvertently end up killing it. Examples include cell proliferation genes that are crucial in embryonic development but at older ages become harmful and can cause cancer and other age-related diseases."
De Magalhaes says the theory provides reason for optimism, as scientists already know many genes regulating development and aging.
"Some hormones like growth hormone and genes involved in insulin-like signaling appear to do just that: they regulate growth and development early in life and later contribute to aging," he says.
Despite this, de Magalhaes warns that there is much work to do before researchers know all of the genes involved.
"Development and aging are so complex that it will be some time before we fully understand them," he says.