The secrets of how malaria became a human-killer have been revealed by a genetic study.
The work, led by researchers from Wellcome Sanger Institute in Cambridge, compared seven types of malaria - tracing the parasite's family tree.
This revealed that, about 50,000 years ago, the parasites diverged, with one "branch" evolving into the most deadly human-infecting species.
The findings are published in the journal Nature Microbiology.
One element of this diversion was a genetic switch that enabled malaria to infect human red blood cells - a "chunk of deadly DNA" that previous studies suggest could yet provide a target for a malaria-blocking vaccine.
"Our study has pieced together the sequential series of steps that set up the critical storm. allowing the parasites to not only enter humans but to stay, divide and be transferred by mosquitoes," explained one of the lead researchers, Dr Matt Berriman.
According to the World Health Organization, more than 200 million people are infected with malaria every year; the disease caused the deaths of almost half a million people globally in 2016, and the majority of those deaths were children under the age of five.
