Origin of Species Variorum

→ p 14 , 1859 1861 1866 1869 1872

p 14 1860

→ f 14 , 1859 1861 1866 1869 1872

f 14 1860

→ m 14 , 1859 1861 1866 1869 1872

m 14 1860

→ and as these latter two genera, both from continued divergence of character and from inheritance from a different parent, will differ 1859 1860 1861 1866

differing 1869 1872

→ three genera descended from (A), the two little 1859 1860 1861 1866

descendants of (A). These two 1869 1872

→ one species of a 1859 1860 1861 1866

some 1869 1872

the extinct species lived at

various remote

very ancient

epochs when the branching lines of descent had diverged less.

I see no reason to limit the process of modification, as now explained, to the formation of genera alone. If, in

the

our

diagram, we suppose the amount of change represented by each successive group of diverging dotted lines to be

~~very~~

very

great, the forms marked a 14 to → p 14 ,

, those

those

marked b 14 and → f 14 ,

, and

and

those marked o 14 to → m 14 ,

, will

will

form three very distinct genera. We shall also have two very distinct genera descended from

(I),

(I);

→and as these latter two genera, both from continued divergence of character and from inheritance from a different parent, will differ widely from the →three genera descended from (A), the two little groups of genera will

thus form

form

two distinct families, or

~~even~~

even

orders, according to the amount of divergent modification supposed to be represented in the diagram. And the two new families, or orders,

are

will have

descended from two species of the original

genus,

genus;

and these

~~two species~~

two species

are supposed to

have

descended from →one species of a still more ancient and unknown

form.

genus.

We have seen that in each country it is the species

belonging to

the larger genera which oftenest present varieties or incipient species. This, indeed, might have been expected;

for,

for

as natural selection acts through one form having some advantage over other forms in the struggle for existence, it will chiefly act on those which already have some advantage; and the largeness of any group shows that its species have inherited from a common ancestor some advantage in common. Hence, the struggle for the production of new and modified

descendants

descendants,

will mainly lie between the larger

groups

groups,

which are all trying to increase in number. One large group will slowly conquer another large group, reduce its numbers, and thus lessen its chance of further variation and improvement. Within the same large