B. are trying to use the same resources
The answer is b. The ability of all living things to maintain a relatively stable internal environment
The fly species Drosophila santomea is found only on a single small island. Thus, this fly is considered to be "Endemic".
The correct answer is: Layer 1, layer 2, and layer 4 in all three regions.
The index fossils are fossils that are commonly used for identifying a geological period of time, and these fossils are also very wide spread, as well as having a rapid evolutionary trends.
By this picture, we can easily see that even though we have rock strata from different regions, the same layers contain the same fossil, and it is a fossil that also is rapidly evolving so has a minor change in each layer.
