| I have seen this particularly in those cases where facultative divergence also was greater than usual. |
| Obligate parasites have an absolute requirement for a host, whereas facultative parasites can live and reproduce in the absence of a host. |
| Although the sample is small, this is a powerful test of the facultative response of females to changes in the composition of their group. |
| Of further interest, these canids also tend toward facultative monogamy and toward minimal sexual dimorphism. |
| Many species of Chlamydomonas are facultative auxotrophs, capable of utilizing acetate as their sole carbon and energy source. |
| The most detailed studies of facultative sociality in bees have focused on the large carpenter bee Xylocopa pubescens. |
