Evolution Practice Quiz (Medium Version)

1. The distinction between homologous and analogous structures can be summarized as follows:

Homologous structures share common ancestral origins while analogous structures do not.

Analogous structures share common ancestral origins while homologous structures do not.

Homologous structures are like bird wings and bat wings, while analogous structures are like dolphin and shark body plans.

None of the above are correct.

Homologous structures are similar in form and function because they share a common ancestry. This means that these structures have evolved from a common ancestor and have been modified over time to serve different purposes in different species. On the other hand, analogous structures may have similar functions but do not share a common ancestry. They have evolved independently in different species to serve similar purposes due to similar environmental pressures. Therefore, the correct answer is that homologous structures share common ancestral origins while analogous structures do not.

Explanation

Homologous structures are similar in form and function because they share a common ancestry. This means that these structures have evolved from a common ancestor and have been modified over time to serve different purposes in different species. On the other hand, analogous structures may have similar functions but do not share a common ancestry. They have evolved independently in different species to serve similar purposes due to similar environmental pressures. Therefore, the correct answer is that homologous structures share common ancestral origins while analogous structures do not.

2. A scientist discovers a previously unidentified primate species and sequences its entire genome and compares it with two currently identified species genomes: Homo sapiens (human) and Pan troglodytes (chimpanzee). Which of the following statements could likely also be correct if the scientist found that the unidentified primate shared more genetic content with the Pan genus than the Homo genus.

The unidentified primate shares greater morphological (physical shape) similarities with humans than with chimps.

The chimp and human posses more morphological similarity to each other than either species does with the unidentified primate.

The unidentified chimp is a hybird offspring of a human and a chimp.

The less genetic difference among a species, the less amount of time has been passed for that ancestral species to have acquired mutations. Therefore, the chimp and the unidentified primate likely share a more recent common ancestor.

Explanation

The less genetic difference among a species, the less amount of time has been passed for that ancestral species to have acquired mutations. Therefore, the chimp and the unidentified primate likely share a more recent common ancestor.

3. Darwin’s theory of descent with modification states that:

Newer forms appearing in the fossil record are the modified descendants older species

Organisms that descend from high elevations are modified as they acquire new traits

All living things descended from a recent common ancestor on the Galapagos Islands

Individuals modify their behavior to survive and then pass those modifications to their descendants

Darwin's theory of descent with modification states that newer forms appearing in the fossil record are the modified descendants of older species. This means that over time, species change and evolve, giving rise to new forms that can be observed in the fossil record. These new forms are not completely different from their ancestors, but rather have undergone modifications and adaptations to better suit their environment and survive. This theory is supported by the evidence of transitional fossils, which show intermediate forms between different species.

Explanation

Darwin's theory of descent with modification states that newer forms appearing in the fossil record are the modified descendants of older species. This means that over time, species change and evolve, giving rise to new forms that can be observed in the fossil record. These new forms are not completely different from their ancestors, but rather have undergone modifications and adaptations to better suit their environment and survive. This theory is supported by the evidence of transitional fossils, which show intermediate forms between different species.

4. A starfish is an animal that has radial symmetry. Which of the following phyla also share a similar body plan type?

Platyhelminthes (ex. planarian worm)

Porifera (ex. sponge)

Chordata (ex. tunicate)

Cnidaria (ex. anemone)

Arthropoda (ex. beetle)

Recall that the cnidarians and ctenophores are the only phyla who also possess the radial body plan - the type in which a central point can be found in which the same body shape radiates out in all directions (360 degrees). The other body type, bilateral symmetry, is found in the remaining animal phyla.

Explanation

Recall that the cnidarians and ctenophores are the only phyla who also possess the radial body plan - the type in which a central point can be found in which the same body shape radiates out in all directions (360 degrees). The other body type, bilateral symmetry, is found in the remaining animal phyla.

5. If Lamarckian evolution were correct, which of the following situations would be likely to happen?

Experimental fruit flies had their wings clipped for 50 generations, and all of their offspring continued to develop wings.

None of the above

If Lamarcking evolution were true (although we know that its implied mechanism is largely not correct), parents would have to acquire a trait and pass on that trait to their offspring. Over long amounts of time and through many generations, the population of individuals who inherited those acquired characteristics would eventually look different than their ancestors (note that the time length is critical - the answer with giraffes had only a single generation resulting in a massive change between parent and offspring)

Explanation

If Lamarcking evolution were true (although we know that its implied mechanism is largely not correct), parents would have to acquire a trait and pass on that trait to their offspring. Over long amounts of time and through many generations, the population of individuals who inherited those acquired characteristics would eventually look different than their ancestors (note that the time length is critical - the answer with giraffes had only a single generation resulting in a massive change between parent and offspring)