There are many different factors, but some are: the amount of natural resources (food, water, etc.), amount of predator/prey, and availability of shelter.
Answer:
Yes both are different. In directional selection one of the extreme traits is favored, whereas in disruptive selection both the extreme traits are favored.
Explanation:
Directional: If selection acts to eliminate one extreme form and supports the other extreme then the peak shifts in the direction which is selected by the nature.
Disruptive: If the selection does not favor the mean character value, rather favors both the peripheral character values then this kind of selection is called disruptive selection.
Firstly they are not membranes and they are villi's which increase the surface area during digestion
