Briefly, outline the mechanism of natural selection. Fill in the blank(s) with the appropriate word(s)

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The proposed mechanism of natural selection for how living things might evolve (change)
with the passage of time. Darwin’s main points include: (1) In any group of organisms, more
offspring are produced than can survive to reproductive age. (2) Random variations occur in
all organisms. Some of these traits are inheritable; they can be passed on to offspring. (3)
Some inheritable traits make an organism better suited to its environment (most do not). (4)
Because bearers of favorable traits are more likely to survive, they are also more likely to
reproduce successfully than bearers of unfavorable traits. Favorable traits tend to accumulate
in the population; they are selected. Unfavorable traits are weeded out by competition. (5)
The physical and biological (natural) environment itself does the selection. Favorable traits
that contribute to the organism’s success show up more often in succeeding generations (if
the environment stays the same). If the environment changes, other traits become
favorable, and the organisms with those traits live most effectively in the new environment