in 2003, mark stoneking, a geneticist at the max planck institute in leipzig, germany, estimated from dna differences that the body louse evolved from the head louse about 107,000 years ago.
2003年,普朗克学院的基因学家斯通金估算体虱大概在十万七千年前于头虱分叉。
so biologists have long been puzzled over the fact that the human head louse is a sister species to the chimpanzee louse, but the pubic louse is closely related to the gorilla louse.
所以生物学家长期为此困惑:为什么人类的头虱是黑猩猩虱子的近亲。而阴虱却是大猩猩虱子的近亲。
the only difference between a head louse is that they are a lot smaller but have a longer abdomen;
唯一的区别,头虱是,他们有很多规模较小,但有一个较长的腹部;