Question

question 39
which of the following does not provide an example of geographic isolation?
two squirrel populations live on opposite sides of a wide, deep river.
two bird populations live on adjacent mountains with a narrow valley between them.
two snail populations live in two valleys on opposite sides of a mountain range.
two fish populations live in different lakes.

Explanation:

Geographic isolation occurs when physical barriers prevent gene - flow between populations. All the options except one describe physical barriers separating populations. In the case of two fish populations in different lakes, they are likely isolated by water bodies which can act as barriers. Similarly, a river between squirrel populations, a valley between bird populations, and a mountain range between snail populations are all examples of geographic isolation. However, if the question is looking for a non - example, we need to analyze each option carefully. But all of these are typical examples of geographic isolation as they involve physical separation of populations by natural geographical features. There seems to be an error in the question as all options provided are examples of geographic isolation.

Answer:

There is no correct answer among the given options as all are examples of geographic isolation.