To reach their conclusion, Dr Rich and Dr Wolfe studied the DNA sequences of malarial parasites collected from nearly 100 wild or formerly wild chimpanzees born in central and west Africa.

• 为得出这一结论，里奇和沃夫博士在中非和西非地区从近100个野生或之前野生的黑猩猩身上收集疟疾寄生虫，并研究了它们的DNA序列。