These biologically plausible assumptions are not concrete, Rosser suggests that climatic conditions may affect the fertility of certain lineages.

Some early plants may have had heteromorphic alternation of generations, with later acquisition of isomorphic gametophytes in certain lineages.

Only later, in certain lineages, did snakes evolve a deadlier bite.

The RAD52 superfamily shows a sporadic phyletic distribution, and even in the crown-group eukaryotes, might have been secondarily lost in certain lineages, such as plants, nematodes and insects.

All wambars are chosen from certain lineages in the Keber moiety.

But as it turned out, they are in fact more closely related to certain lineages of true weevils than these are to other true weevils.

"Our work confirms that not only is this web type very old, it was also lost in certain lineages of spiders."

Further, among the Hassaniya tribes, certain lineages reputed to be descended from the Prophet Mohammed, the chorfa, have played an important role in inter-tribal religious society.

In contrast, the predicted amino-acid hydroxylases of the EGL-9 family are seen sporadically, in single copies, in certain bacterial lineages such as V. cholerae and Ps.

The further specialized a cell is, the more differentiated it is and as a result it is considered to be more committed to a certain cellular lineage.