Many factors affect water quality
Sedimentation.
Runoff.
Erosion.
Dissolved oxygen.
pH.
Temperature.
Decayed organic materials.
Pesticides.
I think observation and measurable.
Answer:
They adapted with new traits to survive to new environments.
Explanation:
survival of the fittest
This phenomenon can be explained by Allen's rule. It says that the body proportions and shape may vary in different climates. The temperature decreases as the latitude increases, so in the northern region is much colder. Animals must preserve heat in such conditions. So, exposed surface areas of the body, such as the ears, feet, and tail, are usually minimized to minimize heat loss in the cold climate. <span>Therefore, northern species often have smaller ears, feet, and tail than the southern species. </span>
