<h2>Answer:</h2>
The two reasons are given below:
- Natural selection.
- Lack of food
<h3>Explanation:</h3>
Natural selection is the phenomenon of the evolution in which the organisms able to fit in the changing environment survive while other organism died. Hence the survival if the fittest and then these organisms. Further reproduce to give birth organisms more fit to the changing environment.
The long neck giraffe survive but short neck died. So the population of long neck increased while short neck go extinct.
Other reason is the change of food resource. The food resource change from grass to long trees.
Answer:
The mechanism is natural selection.
Explanation:
Natural selection is the mechanism that these air-breathing fishes have gone through to survive. This mechanism allows species to survive and reproduce due to differences in the phenotypes of every individual in the specie, throughout the time the heritable traits that every individual inherits changes according to the environment and the characteristics of its ancestors.
Answer:
A. Hypothesis
Explanation:
A hypothesis is a well-tested, scientifically supported statement that explains how something works.