What evidence must be considered when determing whether or not a trait is an adaptation

An adaptation is a trait that "evolved" for a particular condition or circumstance that allows the animal to survive.  Something is adaptive if it is a useful trait but not necessarily one that occurred in response to a particular selection pressure.

An ecosystem is in a certain area and includes living and non living plus there is weather conditions and a biome is a large amount of area with similar climate.so ecosystem is based on weather and biome is based on the average climate