September 8th, 2026
At the high level, without delving into specific mechanisms, the consensus view on aging is that it exists in the shadow of natural selection. The selection pressure that drives the spread of changes in genes, systems, biology in general in any given species operates most strongly on early life reproductive success. This inevitably gives rise to systems that perform well initially, but which fall apart later. Expenditure of resources on long-term maintenance loses out to expenditure of resources on short-term reproductive fitness. Aging is a near universal side-effect of evolutionary competition, a race to the bottom that exists because early life reproductive success wins out over repeated reproductive success for a longer period of time.
That a given aspect of an individual's biochemistry can be beneficial in early life and harmful in later life is known as antagonistic pleiotropy. There are many examples at all scales, ranging from the structure and behavior of the adaptive immune system and its limited capacity for memory, to the well-known trade-off between developmental growth and later risk of age-related disease, to activities of specific proteins such VGLL3. There is a great deal of literature on this topic. Today's open access paper thus treads familiar ground in discussing aging as a side-effect of evolutionary pressures, attempting a modestly different framing of the situation.
