When an organism is best suited for its environment and has a better chance of passing on its traits to the next generation.

There was once a large population of cheetah, but about 12,000 years ago most of the cheetahs were killed off because of human activity and only a few survived and reproduced. What is this an example of?

Evolution by chance, survival of the luckiest:

According to the theory of natural selection, why are some individuals more likely than others to survive and reproduce?

A small group of squirrels gets separates them from the rest of the population due to a large flood. These squirrels, now confined to this new island, begin to start a new population. This is an example of which of the following?

An earthquake creates a new canyon in a mountain area. This canyon separates two populations of mountain turtles to the east and the west of the new canyon. To the west of the new canyon, there are large groves of berry bushes. East of the canyon, there are no berry bushes and only a few plants. However, there is a large river with lots of insects and minnows.

Based on this scenario, what is likely to happen to the two populations of mountain turtles?

In a mouse population inhabiting a grassland area, a mutation occurs that results in a new coat color allele.

Which factor has the GREATEST effect on whether the new coat color will become more common in the mouse population?

The diagram shows light-and dark-colored beetles that live on a tree.

Which result is MOST LIKELY to occur to the beetle population over time due to natural selection?

A population of wolves is living in an area when a tornado strikes and kills most of the wolves. The genetic variation within the wolf population has been greatly reduced.

Which mechanism BEST explains the evolution of this wolf population?

Individuals with intermediate traits are more likely to survive and reproduce

the selection pressure favors the extreme phenotypes, dividing the population into 2 distinct groups

individuals with alleles for an extreme type are more likely to survive and reproduce

Determine which graph best depicts the situation. In a population of field mice, there are many variations of brown, ranging from a very light brown to a very dark brown. The population becomes more of a medium- brown over time, as individuals that best blend in to their surroundings are favored.

If a population of spiders were hunted by sparrows, the large spiders were easy to spot, but moved very quickly; the small spiders were not very easy to spot; the average size spiders were easier to spot than the small ones, but moved more slowly than the large ones, thus making them the most hunted, which type of selection would this be?

individuals with alleles for an extreme type are more likely to survive and reproduce

the selection pressure favors the extreme phenotypes, dividing the population into 2 distinct groups

Individuals with intermediate traits are more likely to survive and reproduce

Tall kelp have a distinct advantage over shorter kelp in receiving needed sunlight in their ocean environment

Seed cracker birds have either large beaks or small beaks. They do not have medium sized beaks because medium sized beaks do not allow for adequate cracking of seeds.

Black rabbits (BB) and white rabbits (bb) are both able to survive because they can camouflage into the white and black rocks in their environment. However, the intermediate gray rabbits (Bb) do not survive. This results in only white and black rabbits.

A population of birds with various size beaks eats seeds. Small seeds can be eaten by birds with small beaks. Larger, thicker seeds can only be eaten by birds with larger, thicker beaks. During a drought, only large thick seeds exist so only the large, thick-beaked birds survive.

Small lizards have difficulty defending territories so they end up dying out. Large lizards are more likely to be preyed upon by owls. Over time, only medium sized lizards end up surviving.