Answer: Directional selection occurs when individuals with traits on one side of the mean in their population survive better or reproduce more than those on the other. ... Directional selection does the “heavy lifting” of evolution by tending to move the trait mean toward the optimum for the environment.
Answer:
It releases carbon dioxide and decreases Earth's supply of oxygen. It absorbs oxygen, thus decreasing Earth's oxygen supply
Explanation:
ANSWER:
I think it's the second one.
EXPLANATION:
in primary succession newly exposed or newly formed rock is colonized by living things for the first time. in secondary succession an area that was previously occupied by living things is disturbed, then recolonizeed following the disturbance.
The circulatory system moves the nutrients from the digestive system to all over the body.