Types of Natural Selection

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

• stabilizing selection

• directional selection

• disruptive selection

Tags

NGSS.HS-LS4-4

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

• directional selection

• stabilizing selection

• disruptive selection

Tags

NGSS.HS-LS4-4

Individuals with intermediate traits are more likely to survive and reproduce

• stabilizing selection

• directional selection

• disruptive selection

Tags

NGSS.HS-LS4-4

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

• directional selection

• disruptive selection

• stabilizing selection

Tags

NGSS.HS-LS4-2

NGSS.HS-LS4-4

Aspen trees that are over 25 m tend to blow over in high winds; aspen that are under 15 m don't get enough sun

• directional selection

• stabilizing selection

• disruptive selection

Tags

NGSS.HS-LS4-4

NGSS.HS-LS4-5

On average, human newborns weigh 7.2 pounds because too small or too large can lead to higher death rates.

• directional selection

• stabilizing selection

• disruptive selection

Tags

NGSS.HS-LS4-2

NGSS.HS-LS4-5

Fish that produce 40,000+ eggs have greater fitness than fish that produce less than this number

• directional selection

• stabilizing selection

• disruptive selection

Tags

NGSS.HS-LS4-2

NGSS.HS-LS4-4

Bacteria that are too large cannot obtain nutrients efficiently and bacteria that are too small cannot compete for those nutrients successfully

• directional selection

• stabilizing selection

• disruptive selection

Tags

NGSS.HS-LS4-2

NGSS.HS-LS4-4

Producing 1000 cactus spines requires too much energy, but producing <500 leaves the plant open to predation

• directional selection

• stabilizing selection

• disruptive selection

Tags

NGSS.HS-LS4-2

NGSS.HS-LS4-4

Light-colored oysters would blend into the rocks in the shallows, and the darkest would blend better into the shadows. The ones in the intermediate range make them easier prey.

• directional selection

• stabilizing selection

• disruptive selection

Tags

NGSS.HS-LS4-2

NGSS.HS-LS4-4