Video Transcript
Parasites, e.g., fleas, living in
the fur of animals have a high death rate. What reproductive strategy would
you expect parasites to use? (A) They will produce few
offspring. (B) They will produce many
offspring. (C) They will invest a lot of
energy in parental care. Or (D) they will not reproduce.
What does reproductive strategy
mean? The reproductive strategy of an
organism refers to the way in which it mates and/or raises offspring. When species live in very harsh
conditions, like fleas, and have a high death rate, that can rapidly bring the
population size down. Such species also tend to produce
very large numbers of offspring. We can also refer to this as a
quantity-over-quality reproductive strategy, in which parents provide little input
or investment beyond simply producing the many offspring.
Let’s say this is a flea colony
with 10 individuals. Due to harsh conditions, they have
a high death rate, and eight out of these 10 individuals die. However, there are still two
individuals left to reproduce. Those two fleas may have 20
offspring in a single clutch of eggs. The eggs also have a high death
rate, so let’s say 12 of those eggs day as well. Although that only leaves two
adults and eight eggs, with such high offspring produced per flea, the species will
be able to survive through the high death rate. So, generally, species with a high
death rate pursue the reproductive strategy of producing many offspring.
Therefore, the correct answer to
this question is (B). The reproductive strategy we would
expect parasites to use is that they will produce many offspring.
