Approaching any task on aging brings a flood of images that are a personal repetition of what has been one of the greatest and most persistent concerns of mankind. Even restricting time to the past decade or so and
approaching only the biomedical sciences, one still encounters a flood of information in this relatively young research area. The­ ories and ideas abound as though each researcher provides one of his own. This might well be
expected; aging is an exceedingly complicated series of crossroads involving trails and even superhighways. Each specialist has a peephole (society, body, organ, tissue, cell, or-especially in modern biology-cellular
organelles, macromolecules, and even molecules) and the views of the crossroads are obviously different. Hence, the num­ ber of observations just about equals the number of independent ideas put forward. It is natural to seek
from highly specialized knowledge a fundamental understand­ ing of aging through the modern research trends in biology that focus on events at the cellular, subcellular, macromolecular, and molecular levels. The ultimate clues
must lie there-with one serious complication: There are numerous cell types in any body and each cell type is a very complex machine of its own. Additionally, there are potential repercussions in that different cells, tissues,
and even molecules have effects on one another. This is indeed a confusing situation, and one for which we must seek reliable answers, provided that we can take a step back and provide a generalized view.