Yeast has long been used by researchers as a model organisms; it is inexpensive and easy to work with and has many genes and cellular functions with a high degree of similarity to human counterparts.
Researchers have now used yeast to learn more about the cellular mechanisms underlying the aging process, discovering some of the genetic mechanisms that drive aging. It is not only a yeast cell or human body growing old and wearing out from use, aging is an dynamic event controlled by a specific group of genes.
It was found that these yeast centarians had special mitochondria, a part of the cell that generates energy, which made more energy and consumed more oxygen than the mitochondria of normal yeast.
The yeast centarians were more resistant to another process involved in aging, oxidative stress.
The other theory suggests that aging is not relevant to evolution; evolution does not have an interest in limiting lifespan so no evolved mechanism to control aging exists.
The researchers have already shown that separate populations of normal and centarian yeast have equivalent reproduction and growth rates, suggesting that aging is indeed a programmed event that is under biological control.