Evolution

The scientific theory of evolution is supported by different types of evidence. 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?

•  It provides information about the organisms' habitats.
•  It shows possible common ancestry between organisms.
• It provides information to determine the organisms' ages.
• It shows possible chromosomal similarities between organisms.

According to fossil records, the horses that lived 50 million years ago were much smaller, weaker and slower than modern horses. Which process is most likely responsible for the changes that have led to the increased size, strength, and speed in horses?

• commensalism
• inbreeding
• migration
• evolution by natural selection

The diagram illustrates an embryonic stage of two organisms.Which of the following can be determined by observing the embryos shown in the diagram? 

• The organisms share a common ancestry.
• The organisms belong to the same genus.
• The organisms are native to the same geographic areas.
• The organisms will grow into anatomically similar adults.

Scientists have found evidence that about 2.4 million years ago a gene regulating jaw muscles mutated and may have led to the more graceful human jaw we see today. The diagram below shows the skulls of 3 hominid species.Which statement below most closely explains the link between jaw size and hominid evolution? 

• The jaws of hominids evolved to be smaller and less protruding over time. 
• The jaws of hominids evolved to be smaller and less protruding over time. 
• There appears to be no change in the jaws of hominids over time.
• The jaws of hominids changed over time due to a change in brain size. 
  

Scientists are studying the evolutionary history of a group of plants in the United States, and they developed an evolutionary tree, as shown below.Which statement can be inferred from the evolutionary tree?

• Species 1 is most closely related to Species 8.
• Species 2 is most closely related to Species 3.
• Species 3 is most closely related to Species 7.
• Species 5 is most closely related to Species 6.

Scientists are studying the evolutionary history of a group of plants in the United States, and they developed an evolutionary tree, as shown below.What information about the organisms best helps the scientists to determine the evolutionary relationships among them?

• DNA sequences
•  Anatomical features
• Habitat types
• Reproductive Strategies

When organisms are better adapted to their environment they will survive and reproduce more successfully than organisms less adapted. This process is called what?

• Selective breeding

• Natural Selection

• Cloning

• Evolution of all species

Sometimes bones in the front limbs of animals are very similar in structure. What do we call similar bone structures that indicate a link to a common ancestor?

• Adaptations

• Gradualism

• Homologous Structures

• Extinction

A physical or behavioral trait that helps an organism survive and reproduce in its environment is called a what?

• An adaptation

• A response to a stimulus

• A mutation

• Evolution

When looking at two birds of the same species, you notice that one has darker feathers than the other one. You also notice that one has a beak that is just a little longer. These slight differences within members of the same species are called.....

• Fossils

• Extinction

• Meiosis

• Variations