The lesson explains patterns of population growth in the UK. It discusses two phases of change before and after 1970. Before 1970, the population grew due to natural increase as the death rate fell due to improved health and hygiene. The birth rate also fell later. After 1970, population growth slowed as birth and death rates declined, resulting in smaller families and longer lifespans. Recent growth is due to immigration rather than natural increase, and migrants are now of child-bearing age. Factors like women's rights, education, costs and globalization contributed to falling birth rates, while healthcare and lifestyle led to increased life expectancy.