Please help me understand this

As China and India grew, the incomes of their numerous citizens tended to converge to those of the citizens of the rich world. At the same time, their incomes diverged from those of the people living in countries that were left behind. Initially, when China and India were very poor, the convergence-to-the rich effect dominated. As they got richer, the divergence-from-the-poor effect got stronger and stronger. If China and India continue to grow over the next 50 years and the incomes of the 700 million Africans remain stagnant, world income inequalities will start rising again