Natural Selection Review

If their environment changes to have only seeds in pinecones, which of the following blue jay populations will most likely survive?

• Populations 1 and 2 will most likely survive as thick beaks are the adaptive trait

• Populations 2 and 3 will most likely survive as thin beats are the adaptive trait

• Only population 2 will survive because it is the only population with variation

• All populations will survive because the blue jays will change the thickness of their beaks if they need to

Tags

pb1

If their environment changes to have only large rocks, which of the following guppy populations will most likely survive?

• Only population 2 will survive because it is the only population with variation

• All the populations will survive because the guppies will change the size of their spots if they need to

• Populations 1 and 2 will most likely survive because small spots is the adaptive trait

• Populations 2 and 3 will most likely survive because large spots is the adaptive trait

Tags

pb1

How did the trait distribution change? From that, how can we infer the environment changed?

• You cannot tell how the environment changed. With each generation, more snakes passed on the gene for red skin to their offspring

• There was more red dirt in the environment. With each generation, more red snakes survived long enough to pass on the gene for red skin to their offspring

• There was more red dirt in the environment. Red snakes are more likely to survive, so the yellow snakes changed to have red skin

• There was more red dirt in the environment. Red snakes are more likely to survive, so both kinds of snakes passed on the gene for red skin to their offspring

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pb2

How did the population distribution change over time? Based on this, can we infer how the environment changed?

• You cannot tell how the environment changed. With each generation, more foxes passed on the gene for brown fur to their offspring

• The environment became brown. Brown foxes are more likely to survive, so the white foxes changed to have brown fur

• The environment became brown. Brown foxes are more likely to survive, so both kinds of foxes passed on the gene for brown fur to their offspring

• The environment came brown. With each generation, more brown foxes survived long enough to pass on the gene for brown fur to their offspring.

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pb2

Which prediction best shows what the population could look like after many generations? What caused it to change?

• Prediction 1 is best. Two hummingbirds with short or medium beaks had a baby with a mutation in its genes for the long-beak trait. Because long-beak hummingbirds are more likely to survive, that baby survived long enough to pass on its mutation, so the long-beak trait became more common over generations

• Prediction 1 is best. Hummingbirds with long beaks are more likely to survive, so hummingbirds with short and medium beaks began to have offspring with a mutation in its genes for the long-beak trait so that their offspring would have a better chance to survive

• Prediction 2 is best. A hummingbird could have been born with a mutation in its genes for the long-beak trait and lived for a little while. Because long-beak hummingbirds are more likely to die, it would have been more likely to die before it had any offspring, so the final population will only have medium or short beak hummingbirds.

• Prediction 2 is best. A hummingbird could have been born with a mutation in its genes for the long beak trait, but having a mutation in its genes would have caused it to die when it was born, so the final population will only have medium or short beak hummingbirds.

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pb3

Which prediction best shows that the population could look like after many generations? What caused it to change?

• Prediction 1 is best. Two seals with thick or medium blubber had a baby with a mutation in its genes for the thin trait. Because thin seals are more likely to survive, that baby survived long enough to pass on its mutation, so the thin trait became more common over generations.

• Prediction 1 is best. Seals with thin blubber are more likely to survive, so seals with thick and medium blubber began to have offspring with a mutation in its genes for the thin trait, so that their offspring would have a better chance to survive.

• Prediction 2 is best. A seal could have been born with a mutation in its genes for the thin trait and lived for a little while, but it would have been more likely to die before it had any offspring, so the final population will only have seals with thick or medium blubber.

• Prediction 2 is best. A seal could have been born with a mutation in its genes for the thin trait, but having a mutation in its genes would have caused it to die when it was born, so the final population will only have seals with thick or medium blubber.

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pb3

Scientists measured the spot size of guppies (small fish) in two different populations. Which population has more guppies with large spots?

• They both have the same number of guppies with large spots

• The population in Brazil has more guppies with large spots

• The population in Venezuela has more guppies with large spots

• These bar graphs do not show which population has more guppies with large spots

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NGSS.MS-LS4-4

Scientists measured the spine size of a population of cactuses found in an area in 1970. They measured the spine size of the cactus population again in 2015. Which of the statements below best describes the difference in the cactuses at the two time points?

• The cactuses in 1970 had smaller spines than the cactuses in 2015

• The cactuses in 1970 had larger spines than the cactuses in 2015

• There were more cactuses in 1970 than there were in 2015

• There was more variation in spine size in 1970 than there was in 2015

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NGSS.MS-LS2-1

NGSS.MS-LS2-4

Who do you think is right? Explain what happened to the guppies over many generations.

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NGSS.MS-LS2-4

NGSS.MS-LS3-1

NGSS.MS-LS4-4