Comparison with 1860 |
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of time, geology plainly declares that all species have
changed; and they have changed in the manner which my theory requires,
for they have changed slowly and in a graduated manner. We clearly see this in the fossil remains from consecutive formations invariably being much more closely related to each other, than are the fossils from formations distant from each other in time.
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Such is the sum of the several chief objections and difficulties which may justly be
urged against my
theory; and I have now briefly recapitulated the answers and explanations which
can
be given
to them.
I have felt these difficulties far too heavily during many years to doubt their weight. But it deserves especial notice that the more important objections relate to questions on which we are confessedly ignorant; nor do we know how ignorant we are. We do not know all the possible transitional gradations between the simplest and the most perfect organs; it cannot be pretended that we know all the varied means of Distribution during the long lapse of years, or that we know how imperfect the
Geological Record
is. Grave
as these several difficulties
are, in my judgment they do not
overthrow
the theory of descent
from a few created forms with subsequent from a few created forms with subsequent 1860 |
with 1859 1869 1872 |
from a few primordial forms with subsequent 1861 1866 |
modification.
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Now let us turn to the other side of the argument. Under domestication we see much variability.
This seems to be mainly
due to the reproductive system being eminently susceptible to changes in the conditions of life; so that this system, when not rendered impotent, fails to reproduce offspring exactly like the parent-form. Variability
is governed by many complex laws,— by correlation
of growth,
by
use and disuse,
and by the direct
action of the physical
conditions
of life.
There is
|
of time, geology plainly declares that
all species have all species have 1859 1860 1861 1866 |
species have all 1869 1872 |
changed; and they have changed in the manner
which my theory requires, which my theory requires, 1859 1860 1861 1866 |
required, 1869 |
required by the theory, 1872 |
for they have changed slowly and in a graduated manner. We clearly see this in the fossil remains from consecutive formations invariably being much more closely related to each other, than are the fossils from
formations distant from each other in time. formations distant from each other in time. 1859 1860 1861 1866 |
widely separated formations. 1869 1872 |
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Such is the sum of the several chief objections and difficulties which may
justly be justly be 1859 1860 1861 1866 1869 | be justly 1872 |
urged against
my my 1859 1860 1861 1866 | the 1869 1872 |
theory; and I have now briefly recapitulated the answers and explanations
which which 1859 1860 1861 1866 1869 | which, 1872 |
can can 1859 1860 1861 1866 1869 |
as far as I can see, may 1872 |
be
given given 1859 1860 1861 1866 | given. 1869 1872 |
to to 1859 1860 1861 1866 | to 1869 1872 |
them. them. 1859 1860 1861 1866 | them. 1869 1872 |
I have felt these difficulties far too heavily during many years to doubt their weight. But it deserves especial notice that the more important objections relate to questions on which we are confessedly ignorant; nor do we know how ignorant we are. We do not know all the possible transitional gradations between the simplest and the most perfect organs; it cannot be pretended that we know all the varied means of Distribution during the long lapse of years, or that we know how imperfect
the the 1859 1860 1861 1866 1869 | is the 1872 |
Geological
Record Record 1859 1860 1861 1866 1869 | Record. 1872 |
is. is. 1859 1860 1861 1866 1869 | is. 1872 |
Grave Grave 1859 1860 1861 | Serious 1866 1869 1872 |
as these several
difficulties difficulties 1859 1860 1861 1866 | objections 1869 1872 |
are, in my judgment they
do not do not 1859 1860 1861 1866 |
are not 1869 |
are by no means sufficient to 1872 |
overthrow overthrow 1859 1860 1861 1866 1872 |
sufficient to overthrow 1869 |
the theory of descent
from a few primordial forms with subsequent from a few primordial forms with subsequent 1861 1866 |
with 1859 1869 1872 |
from a few created forms with subsequent 1860 |
modification. modification. 1859 1860 1861 1866 | subsequent modification. 1869 1872 |
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Now let us turn to the other side of the argument. Under domestication we see much
variability. variability. 1859 1860 1861 1866 |
variability, caused, or at least excited, by changed conditions of life. 1869 |
variability, caused, or at least excited, by changed conditions of life; but often in so obscure a manner, that we are tempted to consider the variations as spontaneous. 1872 |
This seems to be
mainly mainly 1859 1860 1861 | in part 1866 |
due to the reproductive system being eminently susceptible to changes in the conditions of life; so that this system, when not rendered impotent, fails to reproduce offspring exactly like the parent-form.
Variability Variability 1859 1860 1861 1866 1872 | This variability 1869 |
is governed by many complex laws,— by
correlation correlation 1859 1860 1861 1866 | correlation, 1869 | correlated 1872 |
of growth, of growth, 1859 1860 1861 1866 | growth, 1872 | of growth, 1869 |
by by 1859 1860 1861 1866 1869 |
compensation, the increased 1872 |
use and
disuse, disuse, 1859 1860 1861 1866 1869 | disuse 1872 |
and by the direct and by the direct 1859 1860 1861 1866 |
and by the definite 1869 |
of parts, and the definite 1872 |
action of the
physical physical 1859 1860 1861 1866 | surrounding 1869 1872 |
conditions conditions 1859 1860 1861 1866 | conditions. 1869 1872 |
of of 1859 1860 1861 1866 | of 1869 1872 |
life. life. 1859 1860 1861 1866 | life. 1869 1872 |
There is
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