refers to the ecological process involved in the concentric zone model in which a new category of people or type of land use arrives in an area previously occupied by another group or land use.

In some zoos, rare crosses between a male lion and a female tiger have produced hybrid offspring called "ligers." male ligers are sterile but some female ligers are fertile. in the wild, lion and tiger ranges do not naturally overlap, making such a cross unlikely. furthermore, the solitary behavior of tigers and the social organizations of lions create behavioral differences. the production of sterile male ligers is an example of read the following scenario to answer the following question. in some zoos, rare crosses between a male lion and a female tiger have produced hybrid offspring called "ligers." male ligers are sterile but some female ligers are fertile. in the wild, lion and tiger ranges do not naturally overlap, making such a cross unlikely. furthermore, the solitary behavior of tigers and the social organizations of lions create behavioral differences. the production of sterile male ligers is an example of a postzygotic barrier the founder effect sympatric speciation a prezygotic barrier

The map shows latitudes and longitudes of france. which city is located at approximately 48°n, 7°e?

Hilard and clint are seeing a therapist for their sexual difficulties. their homework assignment this week is to caress each other while communicating what is pleasurable to each of them, and to avoid setting any performance goals. this is called the exercise.