Video Transcript
If individuals of a species fail to
reproduce at a fast-enough rate to maintain the population size, which of the
following is most likely to happen? (A) The species will become
extinct. (B) Individual organisms will mate
with other species to produce hybrid animals. (C) Individuals will migrate to new
geographically distinct habitats. Or (D) the process of reproduction
will introduce new harmful mutations into the population.
Let’s look at a model of a
population, where each of the dots represents an individual, to see what happens
when the individuals of a species fail to reproduce at a fast-enough rate. Let’s say these pink Xs represent
individuals in a population that are dying as part of the natural course of
life. And let’s say that the green dots
represent new individuals being born and added to the population as the result of
existing individuals’ reproduction.
When species fail to reproduce at a
fast-enough rate to maintain the population size, the population will reduce in
number. Some individuals may even die
before they can reproduce, reducing the number of offspring further. Essentially, failure to reproduce
may result in more individuals dying than being born. Over time, there will be fewer
individuals from whom to produce offspring and fewer opportunities for each
individual to mate. Eventually, the population may
become so small that members of the species will fail to reproduce at all.
Reproduction is essential for the
survival of a species beyond the life span of the existing members of that
species. If members of a species are not
reproducing, then once those members die out, the species will no longer exist. Eventually, the species will become
extinct. So the correct answer to the
question is (A). The other three answer choices
refer to events that may happen whether individuals in the species are reproducing
or not. Essentially, they are unrelated to
the situation proposed by the question.
If individuals of a species fail to
reproduce at a fast-enough rate to maintain the population size, what is most likely
to happen is that the species will become extinct.
