Answer is: a secretary smokes a cigarette in a crowded break room.
External cost Is when consuming a good or servise imposes a cost to a third party. In this case, smoking affects other people in break room, causing pollution and health related problems.
No they do not make dna not that I think of
Divergent evolution is when two different species share the same ancestral origins but have evolved differently whereas convergent evolution is when species with different ancestral origins have developed similar features.
In convergent evolution, two species that are not necessarily closely related develop similar features often as a result of adaptation to similar conditions.
