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.

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

All the populations will survive because the hummingbirds will change the length of their beaks if they need to.

Populations 1 and 2 will survive.

Populations 2 and 3 will survive.

The water became warm. As a result, ducks with thin feathers were more likely to survive, so the ducks with thick feathers changed to have thin feathers.

The water became warm. As a result, ducks with thin feathers were more likely to survive, so both kinds of ducks passed on the gene for thin feathers to their offspring.

The water became warm. With each generation, more ducks with thin feathers survived long enough to pass on the gene for thin feathers to their offspring.

You cannot tell how the environment changed. With each generation, more ducks passed on the gene for thin feathers to their offspring.

All snakes would survive.

Only yellow and green snakes would survive.

Only the green snakes would survive.

Only the red and green snakes would survive.

The population in Niger has the largest number of tall giraffes.

The population in Somalia has the largest number of tall giraffes.

Both populations have the same number of tall giraffes.

These bar graphs do not show which population has more tall giraffes.  

Populations 1 and 2 will most likely survive.

Populations 2 and 3 will most likely survive.

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

All the populations will survive because the seals will change the thickness of their blubber if they need to.

You cannot tell how the environment changed. With each generation, more guppies passed on the gene for small spots to their offspring.

The rocks became smaller. With each generation, more guppies with small spots survived long enough to pass on the gene for small spots to their offspring.

The rocks became smaller. Guppies with small spots are more likely to survive, so the guppies with large spots changed to have small spots.

The rocks became smaller. Guppies with small spots are more likely to survive, so both kinds of guppies passed on the gene for small spots to their offspring.

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.

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

There were more black trees. Squirrels with black fur are more likely to survive, so the squirrels with gray fur changed to have black fur.

There were more black trees. Squirrels with black fur are more likely to survive, so both types of squirrels passed on the gene for black fur to their offspring.

There were more black trees. With each generation, more squirrels with black fur survived long enough to pass on the gene for black fur to their offspring.

These bar graphs do not show the amount of variation in the population.

There was the same amount of variation in spot size 40 years ago and last year.

There was more variation 40 years ago.

There was more variation last year.