Forces of Evolution
Natural Selection
Evidence
Random
100
The phenomenon where a small, geographically isolated portion of a population experiences a reduction in genetic diversity due to random changes in allele frequencies
What is genetic drift?
100
The environment exerts pressure on a population to change and nature selects those with the best traits to survive.
What is natural selection?
100
Give an example of homologous structures.
human arms, bat wings, and dolphin flippers (same bones, different shapes and sizes for different functions)
100
What are vestigial structures? Give an example.
structures that we have, but no longer use/need. (whale hip/leg bones)
200
What mechanism of evolution occurs when new Blue Jays with a different hue of blue move into a population and interbreed, introducing new genetic variation?
What is Gene flow?
200
Two organisms, such as bats and insects are not related, but they both have wings because they live in similar environments. What are these structures called?
Analogous Structures
200
How can two populations of the same squirrel species become two different species?
geographic isolation, been apart too long, too many differences that they cannot breed anymore
300
In a species of frogs, there is a new color that pops up into the population. What mechanism of evolution is this?
What is mutation?
300
Describe what "fitness" means in regards to natural selection.
What is the organisms ability to survive and reproduce?
300
The diagrams below show the skeletons of two different animal species. How does comparing the skeletons of these animals provide support for the scientific theory of evolution?
A. It provides information about the organisms' habitats.
B. It shows possible common ancestry between organisms.
C. It provides information to determine the organisms' ages.
D. It shows possible chromosomal similarities between organisms.
B. It shows possible common ancestry between organisms.
400
Over evolutionary time, many cave-dwelling organisms have lost their eyes and whales have lost their hind limbs. How can natural selection account for these losses?
A. Natural selection accounts for these losses because if you don’t use it, you lose it.
B. The ancestors of these organisms experience harmful mutations that forced them to new habitats that these species had not previously used.
C. Under particular circumstances that persisted for long periods of time, each of these structures did not benefit the organism in their environment.
D. These organisms did not have the proper nutrition leading to disease.
C. Under particular circumstances that persisted for long periods of time, each of these structures did not benefit the organism in their environment.
400
The North American cactus and African Euphorbia (plant) are species that have evolved similar structural adaptations to conserve water and survive in a hot, dry, desert environment. They appear similar in appearance, but are not related. What type of evolution are these species demonstrating?
A. Coevolution
B. Divergent
C. Convergent
D. Mutualism
What is Convergent?
500
A tornado wipes out half the community of grasshoppers. What mechanism of evolution is this?
What is genetic drift?
500
You are studying with one of your fellow classmates and they state, "The giraffe stretched its neck while reaching for higher leaves resulting in its offspring with inherited longer necks." Which statement is most likely to be helpful in correcting this student's misconception?
A. Characteristics obtained during an organism's life are generally not passed onto the offspring.
B. Mutations can result in the appearance of new traits
C. If giraffes did not have to compete with each other, longer necks would not have been passed onto the next generation
D. The offspring with long necks will reproduce offspring with longer necks
D. The offspring with long necks will reproduce offspring with longer necks
500
What does this picture tell us about these organisms? Why?
They share a common ancestor because their development is similar.
500
It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that
A. Island species and mainland species descended from common ancestors
B. Common environments are inhabited by the same organisms
C. Island species have the same mutations as the mainland species
D. The island species and mainland species are converging
A. Island species and mainland species descended from common ancestors