WGU C451/GNC2/1NC1 Integrated
Natural Sciences Module 8
Explain the concept of natural selection. – ✔✔It is a process where organisms with advantageous
traits leave more offspring than organisms with other traits – causing populations to change over
time. (key mechanism of evolution)
variation – ✔✔traits vary from individual to individual
heritable traits – ✔✔A trait that can be passed on genetically from parent to offspring.
fitness – ✔✔the number of offspring an organism leaves over its lifetime compared to other
individuals in the population
Describe an example of a population that changes over time due to natural selection. How do
variation, heritable traits, fitness and natural selection allow change in the population to occur? –
✔✔peppered moth, rat snake, humans, deer mouse, pesticide resistant insects, Galapagos
finches, peacocks, warrior ants, nylon-eating bacteria, and lizards. (They have all adapted &
made changes to support the environments they live in)
Explain why adaptations are an important component of a species’ survival. – ✔✔because they
are important for survival. If the specie does not adapt to its environment it lives in, it will not
survive
Describe adaptations of animals in extreme environments, such as a polar bear (in a cold, arctic
environment) or – ✔✔Polar Bear (cold- arctic environment): larger, tend to have a smaller
surface area-to-volume ratio, their volume increases rapidly due to growing so quickly
(Bergmann’s Rule), short appendages (Allen’s Rule) & small ears to conserve heat, although
polar bears seem white, they are transparent, which allows sun to transmit to skin below, they
have insulating layers that conduct heat slowly & slow down heat loss.
Describe adaptations of animals in extreme environments, such a desert rabbit (in a hot, dry,
desert environment). – ✔✔Desert Rabbit (hot-dry-desert environment): smaller, long legs, large
ears that increase the surface area available for heat dissipation, extensive blood vessels that
carry heat from core of body to skin where convection cool them off, pale in color.
Describe how variation, heritability, fitness, and natural selection contributed to the evolution of
peppered moths – ✔✔Variation: There are varying kinds of colors that can be selected by nature
between the moths. Heritability: The idea that if you had more dark colored moths, they would
give birth to dark colored baby moths which would grow up to be again a dark colored moth. It’s
an inheritable trait Fitness: you had increased survival depending on what color choice you were.
Natural Selection Contributed to the Evolution: had a change in the environment. We had this
habitat change, where we had a change of the color of trees. Change due to Industrial Revolution
and all the pollution ash and smog.