Genetics and Evolution STAAR Review

Which of the following is the best evidence that mammals evolved from reptiles?

• Similarities in the diets of extinct reptiles and modern mammals
• Similarities in the average lifespans of modern reptile and modern mammals
•  Fossils of ancient reptiles and mammals that appear together in the same layers of rock

The Galapagos Islands, a small group of islands off the coast of Ecuador, is home to reptiles such as the giant tortoise and the iguana. The eastern islands are much older than the islands to the west.  Which statement about the origin of these reptiles is best supported by this information?

• The ancestor of each species came from different continents at different times.
• The common ancestors of the reptiles probably came from Equador.
• The common ancestor of each species evolved in Peru and came to the islands at the same time.

The different species of the Hawaiian honeycreepers shown all descended from a single species of North American bird. They now have different beaks, eat different food, sing different songs, and live in different environments on the islands. Which factor probably contributed MOST to the development of these different species?

• Loss of habitat
• Geographical isolation
• Egg size
• Predation

What is the advantage of having different shaped beaks?

• To look different from other species.
• To be able to eat the food readily available in the environment.
• To protect itself against predators.
• To protect itself against prey.

Scientists compare the limbs of organisms to look for evidence of common ancestry. These limbs provide evidence of common ancestry because they -

• perform the same function
• are the same size
• have the same basic structure
• are parts of the same animal

The picture shows the members of the Camelidae family. The physical features and the geographical origin of these animals provide evidence that - 

• they live in the same type of environment.
• have slowly evolved to become herbivores.
• have a common ancestor.
• exchanged DNA in the past.

Which of the following is the best example of natural selection?

•  The lifespan of a chimpanzee is extended to 60 years in captivity
•  The population size of giraffes changes over time as a result of immigration
•  A populations of bunnies select for brown fur when winter is approaching
•  Ants develop poisonous chemicals in response to high predation

The diagram shows fossils in different rock layers. Which of these statements about the age of these fossils is most likely correct?

• Fossil A and C are the same age
  
• Fossil B is older than fossil C
• Fossils A is older than fossil B
• Fossil D is older than fossil C

 A scientist wants to determine if two species of mammals are related. Which of the following is the best evidence in determining if the species had a common ancestor.

•  Both species move in similar ways
• Both species both live in the same area
•  Both species have very similar DNA sequences
• The embryos of both species are similar

What conclusions can be made based on this table shown?

• the American black bear and the giant panda are most closely related
• the giant panda and the red panda are most closely related
• the red panda and the racoon are the most closely related