Answering the question as to why we age is tantamount to answering the question of what is life itself. There are countless theories as to why and how we age, but, until recently, the very definition of aging – senescence – was still uncertain. Here, we summarize the main views of the different models of senescence, with a special emphasis on the biochemical processes that accompany aging. Though inherently complex, aging is characterized by numerous changes that take place at different levels of the biological hierarchy. We therefore explore some of the most relevant changes that take place during aging and, finally, we overview the current status of emergent aging therapies and what the future holds for this field of research. From this multi-dimensional approach, it becomes clear that an integrative approach that couples aging research with systems biology, capable of providing novel insights into how and why we age, is necessary.

In this paper the Pair of Siblings Paradox introduced by Pereira [1] is extended by considering more than two children and more than one child observed for gender. We follow the same lines of Wechsler et al.[2] that generalizes the three prisoners' dilemma, introduced by Gardner [3]. This paper's conjecture is that the Pair of Siblings and the Three Prisoners dilemma are dual paradoxes. Looking at possible likelihoods, the sure (randomized) selection for the former is non informative (informative), the opposite that holds for the latter. This situation is maintained for generalizations. Non informative likelihood here means that prior and posterior are equal.