The skin of the animal<span> is one of the first systems affected so it is the first indicator when an </span>animal becomes sick. The skin of an animal should be examined for signs of disease. Examined should be the structure and the <span>functioning of the skin. If there are some abnormalities it can be sign that the animal is sick. </span>
To breathe, they use the <span>the carbon dioxide. Carbon dioxide is the main element which help the organisms to breathe.</span>
Answer:
The finches on Galapagos Islands had different beak
The beaks of the finches changed over time
The Galapagos finches had a common ancestor
Explanation: Darwin's Finches are a good example of natural selection and adaptive radiation of evolution. The different finches in Galapagos Island have emerged from a common black, seed eating, short beak finches. This is called adaptive radiation, where different species arose from a single ancestor.
Due to changes in the natural environment, food resources, some finches have a long beak. This long beaks help them to eat insects. As a result, the competition will be less and nature selects them to survive in the new environment. This is a natural selection of evolution.