1 An introduction to ageing

Human beings are complex life systems. As you get older, you experience the effects of ageing. But what is the ageing experience?

There are certain ‘hallmarks of ageing’. Figure 1 is based on research into the ageing process using insects as models, but the process equally applies to human beings.

There are many complicated processes going on here, but you don’t need to know the details. The most apparent hallmark of ageing is ‘genomic instability’. Here, the effect of unstable genomes could reduce life expectancy. All of the ‘hallmarks of ageing’ indicate a reduction in life expectancy. So how does this affect human beings in the 21st century?

You probably know that the population of the world is increasing and that older people are living longer. This is reported in the news almost every day. There are constant worries in western society about how to support our ageing populations, from providing care homes and long-term medical care (which can be very expensive) to state pensions. As a direct result of statistical analysis, most people are well aware of these financial implications; from reduced life insurance premiums to an increase in retirement age.

Figure 2 indicates how the population of the world changed between 1950 and 2000, and how it is anticipated to increase by 2050. This chart was produced by the Population Division of the Department of Economic and Social Affairs of the United Nations in 2005, so it is already out of date.

Now, using the data in Figure 2, complete Activity 1.