Types of Natural Selection Flashcards
3 types of natural selection
directional, stabilizing, and disruptive
Directional Selection
When individuals at one end of the curve have higher fitness than individuals in the middle or at the other end
Stabilizing Selection
individuals near the center of the curve have higher fitness than individuals at either end of the curve
Disruptive Selection
individuals at the upper and lower ends of the curve have higher fitness than individuals near the middle
Why does the curve of a directional selection shift?
The range of phenotypes shifts as some individuals fail to survive and reproduce while others succeed.
What does the graph of a stabilizing population look like?
keeps the center of the curve at its current position, but it narrows the overall graph
What must happen for disruptive selection to occur?
a pressure that is strong enough and lasts long enough
(makes it possible to split the single curve into 2 and result in 2 distinct phenotypes)