Ageing
Ageing is the accumulation of changes over time, affecting most organisms.
Ageing (or aging in American English) describes the process of getting older. While the term mainly applies to humans, many other animals, and fungi, some life forms—such as bacteria, perennial plants, and certain simple animals—are considered potentially biologically immortal. More broadly, ageing can refer to individual cells within an organism that have stopped dividing, or to the overall population of a species. In humans, ageing involves the buildup of changes over time, affecting physical, psychological, and social aspects. For instance, reaction time may slow, while memory and general knowledge often increase. Of the roughly 150,000 people who die each day across the globe, about two-thirds – 100,000 per day – die from age-related causes. Current theories on ageing fall into two main categories. The damage concept holds that accumulated harm—like DNA oxidation—causes biological systems to fail. The programmed ageing concept suggests that internal processes, such as epigenetic maintenance like DNA methylation, inherently drive ageing. Programmed ageing is distinct from programmed cell death, or apoptosis.
Quick Facts
- Field
- Biology, Gerontology
- Known for
- Process of becoming older
- accumulation of damage or programmed ageing
- major risk factor for human diseases
Facts from the source article.
Lore & Background
Current ageing theories are assigned to the damage concept, whereby the accumulation of damage (such as DNA oxidation) may cause biological systems to fail, or to the programmed ageing concept, whereby internal processes (epigenetic maintenance such as DNA methylation) inherently may cause ageing. Programmed ageing should not be confused with programmed cell death (apoptosis). Early life forms on Earth, starting at least 3.7 billion years ago, were single-celled organisms. Such organisms multiply by fission into daughter cells; thus single celled organisms have been thought to not age and to be potentially immortal under favourable conditions. However, evidence has been reported that aging leading to death occurs in the single-cell bacterium Escherichia coli and the yeast Saccharomyces cerevisiae.
Frequently Asked Questions
What is Ageing?
Ageing is the lifelong, progressive accumulation of biological, psychological, and social changes that make an organism older. It is most prominently observed in humans, many animals, and fungi.
What drives Ageing at the cellular level?
Two main hypotheses dominate the field: the damage-accumulation model, where molecular and cellular wear builds up over time, and the programmed-ageing model, where genetic timers trigger decline. Gerontologists generally believe both mechanisms contribute to the overall process.
Do all living things experience Ageing?
No. Bacteria, perennial plants, and some simple animals appear to be biologically immortal and do not show the typical functional decline we associate with growing old. Ageing is a feature primarily of complex multicellular organisms like humans, most animals, and fungi.
Why is Ageing the biggest risk factor for human disease?
As cells and tissues accumulate damage or follow a programmed decline pathway, the body's repair and regulatory systems become less effective. This makes advanced age the single strongest predictor of conditions ranging from cancer to cardiovascular and neurodegenerative diseases.
Which fields of study focus on Ageing?
Gerontology is the dedicated discipline that examines the biology, psychology, and social dimensions of growing older. It sits within the broader field of biology and draws heavily on genetics, medicine, and public health.
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