During periods of rapid environmental change, what may happen to a species that was well-suited to the former environment?

The environment usually refers to all the biotic and the abiotic components that are surrounding us. This environment undergoes changes depending upon various factors which can be natural and/or due to the anthropogenic activities.

When there occur rapid environmental changes, then it directly affects the lives of species, in different ways, such as-

Those species that are comparatively weaker in adapting according to the environmental changes that occur, will not be able to cope up with the new environment. They may become extinct. Some variety of species will be able to adapt to the new environment because of their easily adapting capabilities. The traits that will be developed within the species in the new environment will be more successful in terms of reproduction. The previously existed traits may have a harmful impact in the newly formed environment.

It is evolution, because we all have some of the same traits like eye color or shape or ears.