对，，起作用， - account for, be responsible for

Although low population densities may account for the detection of some lineages only within relatively small regions of Africa, other factors may be responsible for the minimal degrees of movement observed for fairly common lineages, such as MSV-A4V (zones 13 and 14 in Fig. 2M), corroborating the commonly observed localization of MSV-A4 genomes to southern Africa (39, 69).