Which of the following is NOT a plausible explanation for the mismatch between the
predicted number of extinctions and the number of extinctions actually observed in
historic times?
Most species are unknown to science, and so their disappearance could not have been
documented.
It is difficult to be certain that every last individual of a species is dead, and scientists try to
be relatively certain before making the call.
Extinctions of highly sensitive species occur shortly after human colonization, so the
remaining species tend to be more tolerant of human disturbance and less extinction prone.
No one has bothered to try to document actual extinctions.
