With 224 million people, Nigeria is Africa's most populous country. By 2050, it could crack the global top three with some 375 million people. In the second of our two-part series on the global population passing eight billion, National Geographic photographer Yagazie Emezi describes scenes she captured in Lagos, Africa’s biggest city—including intimate close-ups of a family raising four children in a one-room apartment and women receiving prenatal care. Plus, a Nigerian demographer explains how the country's soaring birth rate could make it an economic powerhouse, but only if the country finds new ways to invest in its youthful population. For more information on this episode, visit natgeo.com/overheard. Want more? See Yagazie Emezi’s photos—and other scenes from a world with 8 billion people—in the April issue of National Geographic.   For a previous National Geographic assignment, Yagazie photographed the women stepping up to remake Rwanda. Follow her on Instagram @yagazieemezi. Also explore: With a get-rich spirit that fuels the continent’s largest economy, see why Lagos has become Africa’s boom town. Read more from Akanni Akinyemi, including how Africa will shape the future of the planet’s population.  Learn more about your ad choices. Visit megaphone.fm/adchoices