Why is reproductive isolation required for speciation to occur?

In iceland, the mid atlantic ridge runs through the center of the contry. what can you conclude about the apperence of iceland many thousands of years from now?

Which measure of an earthquake depends on how close you are to the focus?

The table presents the average day and night temperatures in five cities. it also reveals whether a city receives substantial rainfall (wet climate) or little rainfall (dry climate). which city’s rocks are likeliest to experience frost wedging, and why? a) city a because the consistently subzero temperature would prevent water from melting b) city b because it is a wet region and the temperature fluctuates around the freezing point c) city c because it receives plenty of rain fall and the weather is moderately cool d) city d because the hot and dry weather would cause rocks to absorb water