Comparison with 1860 |
|
always prefer
getting getting 1859 1860 1861 1866 | saving 1869 1872 |
seed from a large body of
plants plants 1859 1860 1861 1866 | plants, 1869 1872 |
of of 1859 1860 1861 1866 | as 1869 1872 |
the
same variety, as the same variety, as the 1859 1860 1861 1866 |
OMIT 1869 1872 |
chance of intercrossing
with other varieties with other varieties 1859 1860 1861 1866 |
OMIT 1869 1872 |
is thus lessened. |
|
Even
in the case of slow-breeding in the case of slow-breeding 1859 1860 1861 1866 |
in the case of 1869 |
with 1872 |
animals, animals, 1859 1860 1861 1866 | animals 1869 1872 |
which
unite unite 1859 1860 1861 1866 1872 |
breed slowly and unite 1869 |
for each birth, we
must not
overrate overrate 1859 1860 1861 1866 |
assume that 1869 |
assume that free intercrossing would always eliminate 1872 |
the effects of
intercrosses in retarding intercrosses in retarding 1859 1860 1861 1866 |
OMIT 1869 1872 |
natural
selection; selection; 1859 1860 1861 1866 1872 | selection 1869 |
for for 1859 1860 1861 1866 1872 |
will always be immediately overpowered by free intercrossing; for 1869 |
I can bring
a considerable catalogue a considerable catalogue 1859 1860 1861 1866 |
a considerable body 1869 |
forward a considerable body 1872 |
of facts,
showing that within the same area, varieties
of the same animal
can can 1859 1860 1861 1866 | may 1869 1872 |
long remain distinct, from haunting different stations, from breeding at slightly different seasons, or from varieties of the same kind
preferring to pair together. |
|
Intercrossing plays a very important part in nature in
keeping the individuals of the same species, or of the same variety, true and uniform in character. It will obviously thus act far more efficiently with those animals which unite for each birth; but
I have already attempted to show that I have already attempted to show that 1859 1860 1861 1866 |
as already stated 1869 |
as already stated, 1872 |
we have reason to believe that occasional intercrosses take place with all animals and with all
plants. Even if these take place only at long
intervals, intervals, 1859 1860 1861 1866 | intervals 1869 1872 |
I am convinced that I am convinced that 1859 1860 |
of time, 1869 1872 |
OMIT 1861 1866 |
the young thus produced will gain so much in vigour and fertility over the offspring from long-continued self-fertilisation, that they will have a better chance of surviving and propagating their kind; and thus, in the long run, the influence of intercrosses,
even at rare intervals, will be great. If there exist
organic beings which never
intercross, uniformity of character can be retained amongst
them,
as long as their
conditions of life
remain the same,
only through the principle of
inheritance, inheritance, 1859 1860 1861 1866 1872 | inheritance 1869 |
and through natural selection destroying any which depart
from the proper type;
but if their
conditions of life change and they
undergo
modification, uniformity of character can be given to their
modified offspring, solely by natural selection preserving
the same the same 1859 1860 1861 1866 | similar 1869 1872 |
favourable variations. |
|
Isolation, also, is an important element in the
process of process of 1859 1860 1861 1866 |
changes effected through 1869 |
modification of 1872 |
|
always prefer
saving saving 1869 1872 | getting 1859 1860 1861 1866 |
seed from a large body of
plants, plants, 1869 1872 | plants 1859 1860 1861 1866 |
as as 1869 1872 | of 1859 1860 1861 1866 |
the
...OMIT 1869 1872 |
same variety, as the 1859 1860 1861 1866 |
chance of intercrossing
...OMIT 1869 1872 |
with other varieties 1859 1860 1861 1866 |
is thus lessened. |
|
Even
in the case of in the case of 1869 |
in the case of slow-breeding 1859 1860 1861 1866 |
with 1872 |
animals animals 1869 1872 | animals, 1859 1860 1861 1866 |
which
breed slowly and unite breed slowly and unite 1869 |
unite 1859 1860 1861 1866 1872 |
for each birth,
we we 1859 1860 1861 1866 1869 |
and which do not propagate rapidly, we 1872 |
must not
assume that assume that 1869 |
overrate 1859 1860 1861 1866 |
assume that free intercrossing would always eliminate 1872 |
the effects of
...OMIT 1869 1872 |
intercrosses in retarding 1859 1860 1861 1866 |
natural
selection selection 1869 | selection; 1859 1860 1861 1866 1872 |
will always be immediately overpowered by free intercrossing; for will always be immediately overpowered by free intercrossing; for 1869 |
for 1859 1860 1861 1866 1872 |
I can bring
a considerable body a considerable body 1869 |
a considerable catalogue 1859 1860 1861 1866 |
forward a considerable body 1872 |
of
facts, facts, 1859 1860 1861 1866 1869 | facts 1872 |
showing that within the same area,
varieties varieties 1859 1860 1861 1866 1869 | two varieties 1872 |
of the same animal
may may 1869 1872 | can 1859 1860 1861 1866 |
long remain distinct, from haunting different stations, from breeding at slightly different seasons, or from
varieties of the same kind varieties of the same kind 1859 1860 1861 1866 1869 |
the individuals of each variety 1872 |
preferring to pair together. |
|
Intercrossing plays a very important part in nature
in in 1859 1860 1861 1866 1869 | by 1872 |
keeping the individuals of the same species, or of the same variety, true and uniform in character. It will obviously thus act far more efficiently with those animals which unite for each birth;
but but 1859 1860 1861 1866 1869 | but, 1872 |
as already stated as already stated 1869 |
I have already attempted to show that 1859 1860 1861 1866 |
as already stated, 1872 |
we have reason to believe that occasional intercrosses take place with all animals and
with all with all 1859 1860 1861 1866 1869 | with all 1872 |
plants. Even if these take place only at long
intervals intervals 1869 1872 | intervals, 1859 1860 1861 1866 |
of time, of time, 1869 1872 |
I am convinced that 1859 1860 |
OMIT 1861 1866 |
the young thus produced will gain so much in vigour and fertility over the offspring from long-continued self-fertilisation, that they will have a better chance of surviving and propagating their kind; and thus, in the long run, the influence of
intercrosses, intercrosses, 1859 1860 1861 1866 1869 | crosses, 1872 |
even at rare intervals, will be great.
If there exist If there exist 1859 1860 1861 1866 1869 |
With respect to 1872 |
organic beings
which never which never 1859 1860 1861 1866 1869 |
extremely low in the scale, which do not propagate sexually, nor conjugate, and which cannot possibly 1872 |
intercross, uniformity of character can be retained
amongst amongst 1859 1860 1861 1866 1869 | by 1872 |
them, them, 1859 1860 1861 1866 1869 | them 1872 |
as long as their as long as their 1859 1860 1861 1866 1869 |
under the same 1872 |
conditions of
life life 1859 1860 1861 1866 1869 | life, 1872 |
remain the same, remain the same, 1859 1860 1861 1866 1869 |
OMIT 1872 |
only through the principle of
inheritance inheritance 1869 | inheritance, 1859 1860 1861 1866 1872 |
and through natural selection
destroying any which depart destroying any which depart 1859 1860 1861 1866 1869 |
which will destroy any individuals departing 1872 |
from the proper
type; type; 1859 1860 1861 1866 1869 | type. 1872 |
but if their but if their 1859 1860 1861 1866 1869 |
If the 1872 |
conditions of life change and
they they 1859 1860 1861 1866 1869 | the 1872 |
undergo undergo 1859 1860 1861 1866 1869 | form undergoes 1872 |
modification, uniformity of character can be given to
their their 1859 1860 1861 1866 1869 | the 1872 |
modified offspring, solely by natural selection preserving
similar similar 1869 1872 | the same 1859 1860 1861 1866 |
favourable variations. |
|
Isolation, also, is an important element in the
changes effected through changes effected through 1869 |
process of 1859 1860 1861 1866 |
modification of 1872 |
|