Evolutionary History Chapter 3

This bandicoot, this sea lion, and this zebra have similarities and differences in their body structures. What does the information about these structures tell you about the ancestors of these species?

• Sea lions and zebras share the same ancestor population, but they must not share an ancestor with bandicoots because sea lions and zebras do not have a pouch for their babies.
• None share an ancestor population because different species cannot share an ancestor population. It is a coincidence that these species have some of the same body structures.
• All three species share an ancestor population, but sea lions and zebras share a more recent ancestor population. This is why neither shares the pouch structure for their babies.
• We cannot make observations of ancestor populations from the past. It is impossible to explain ancestors with only the information about the body structures of different species.

What does this diagram show?

• All three species share a common ancestor, but the African elephant and Sumatran tiger are more closely related to each other than they are to the Norway rat.
• All three species share a common ancestor, but the Sumatran tiger and Norway rat are more closely related to each other than they are to the African elephant.
• The Sumatran tiger, African elephant, and Norway rat are not related and come from separate lines of evolutionary history.
• All three species share a common ancestor and are equally related to each other.

This red-eared slider, this greater flamingo, and this siamang have similarities and differences in their body structures. What does the information about these structures tell you about the ancestors of these species?

• The red-eared slider and the greater flamingo share an ancestor population, but they must not share an ancestor with the siamang because red-eared sliders and greater flamingos lay eggs, but siamangs give live birth.
• All three species share an ancestor population, but the red-eared slider and the greater flamingo share a more recent ancestor population. This is why they share the egg-laying structure.
• We cannot make observations of ancestor populations from the past. It is impossible to explain ancestors with only the information about the body structures of different species.
• None share an ancestor population because different species cannot share an ancestor population. It is a coincidence that these species have some of the same body structures.

This echidna, this natterjack toad, and this blue tang have similarities and differences in their body structures. What does the information about these structures tell you about the ancestors of these species?

• We cannot make observations of ancestor populations from the past. It is impossible to explain ancestors with only the information about the body structures of different species.
• None share an ancestor population because different species cannot share an ancestor population. It is a coincidence that these species have some of the same body structures.
• All three species share an ancestor population, but echidnas and natterjack toads share a more recent ancestor population. This is why they share the neck-bone structure.
• Echidnas and natterjack toads share an ancestor population, but they must not share an ancestor with the blue tang because blue tangs have no neck bones.

What does this diagram show?

• All three species share a common ancestor, but the bold jumping spider and Bombay locust are more closely related to each other than they are to the common octopus.
• All three species share a common ancestor, but the bold jumping spider and common octopus are more closely related to each other than they are to the Bombay locust.
• The three species are not related and come from separate lines of evolutionary history.
• All three species share a common ancestor and are equally related to one another.

This locust, this jumping spider, and this Roman snail have similarities and differences in their body structures. What does the information about these structures tell you about the ancestors of these species?

• All three species share an ancestor population, but locusts and jumping spiders share a more recent ancestor population. This is why they share the exoskeleton structure.
• We cannot make observations of ancestor populations from the past. It is impossible to explain ancestors with only the information about the body structures of different species.
• Locusts and jumping spiders share an ancestor population, but they must not share an ancestor with Roman snails because Roman snails have a shell.
• None share an ancestor population because different species cannot share an ancestor population. It is a coincidence that these species have some of the same body structures.

What is a part of an organism (for example, one or more bones) called

• ancestor
• body structure
• fossil
• trait

What is a common ancestor population?

• a more recent species that evolved from an ancestor population
• an older population from which two or more newer species descended
• a part of an organism (for example, one or more bones)
• the process by which species adapt to environmental changes over a very long time

What does related mean?

• sharing a common ancestor population
• the process by which one population evolves into two or more different species
• a group of the same type of organism living in the same area
• a random change to a gene that sometimes results in a new trait

True or False: When two species share a structure that is not shared with a third species, this can be evidence that the first two species are more closely related to each other than to the third species.

• True
• False