|
The excerpt represents the core issue or deciding factor on which you must meditate, and is drawn from On the Origin of Species by Charles Darwin: climate being conspicuous, we are tempted to attribute the whole effect to
its direct action. But this is a very false view: we forget that each
species, even where it most abounds, is constantly suffering enormous
destruction at some period of its life, from enemies or from competitors
for the same place and food; and if these enemies or competitors be in the
least degree favoured by any slight change of climate, they will increase
in numbers, and, as each area is already fully stocked with inhabitants,
the other species will decrease. When we travel southward and see a
species decreasing in numbers, we may feel sure that the cause lies quite
as much in other species being favoured, as in this one being hurt. So it
is when we travel northward, but in a somewhat lesser degree, for the
On the Origin of Species |
