If the offspring is born with some characteristic that gives it a better chance of survival in the environment into which it is born, it is more likely to live long enough to find a mate and reproduce, or produce more offspring than creatures without the new characteristic.
(the offspring; is born; ) (some characteristic; gives; it; a better chance of survival in the environment) (it; is born; L:the environment) (it; is; more likely to live long enough to find a mate and reproduce, or produce more offspring than creatures without the new characteristic)
the offspring some characteristic it it
is born gives is born is
it a better chance of survival in the environment
L:the environment
more likely to live long enough to find a mate and reproduce, or produce more offspring than creatures without the new characteristic