Four experts tell the BBC World Service Inquiry programme how the expected doubling of Africa's population by 2050 will affect the continent.
This graphic is a condensed, and static version of one of Gapminder's famous animated "worm" graphics. Scaling the diameters of the circles according to the years, and then connecting them, induces a sense of motion over time, even in this static image. It is fascinating to see how Vietnam is today on the same level as the US in 1980 with respect to the fertility rate and life expectancy. Also note how the dip in Botswana's curve reflects the drastic effects of AIDS in this country in the 1980s.