JOHANNESBURG (AP) - Dr. Sikhulile Moyo was analyzing COVID-19 samples in his lab in Botswana last week when he noticed they looked startlingly different from others.Within days, the world was ablaze with the news that the coronavirus had a new variant of concern — one that appears to be driving a dramatic surge in South Africa and offering a glimpse of where the pandemic might be headed.New COVID-19 cases in South Africa have burgeoned from about 200 a day in mid-November to more than 16,000 on Friday.