The sun's light and heat, for one thing, are necessary, and
though the bulk of combustible material in the sun is enormous, there
must be some end to it. Sir William Thomson has calculated (and his
calculations have never been answered) that on purely physical grounds,
the existence of life on the earth must be limited to some such period
as 100 millions of years; and this is far too short for uncontrolled
evolution.
We know from fossils, that species have remained entirely unaltered
since the glacial epochs began, and how many generations are included
even in that! If no change is visible in all that time, how many more
ages must have elapsed before a primitive _Amoeba_ could have developed
into a bird or a Mammal?
In Florida Mr. Agassiz has shown that coral insects exist unchanged,
and must have been so for 30,000 years.
When we remember also the enormous destruction of life that takes place,
supposing that in a given form a few creatures underwent accidental
changes which were beneficial and likely to aid them--still what chances
were there that the creatures which began to exhibit the right sort of
change should have died before they left offspring! the chances against
them are enormous: and the chances have to be repeated at every
successive change before the finally perfected or advanced creature took
its place in the polity of nature.
Pages:
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92