A defining characteristic of sympatric speciation is Group of answer choices a. The appearance of new species in the midst of old ones b. Asexually reproducing populations c. Geographic isolation. d. Artificial selection e. Large populations

Witch layer of the atmosphere has the most air pressure

How does rain water cause erosion and deposition? a. when acidic water soaks into the ground, water dissolves limestone, resulting in the formation of caves.b. when a river overflows it moves downhill resulting in the formation of caves.c. when it rains, water flows into rivers and streams and moves back to land, resulting in the formation of caves.d. when water empties into lakes, sediment is deposited, resulting in formation of caves.

The hypothetical island country of gilder lies in the mediterranean sea off the coast of france. demographers have studied gilder for the past 50 years. at the beginning of the study, gilder had a population of 20 million. the demographers have measured birth and death numbers, as well as immigration and emigration numbers, as shown in the data table. from the data, calculate the population of gilder for each 10-year period by filling in the population (no) and population (nt) columns in the data table. use this formula to do your calculations: population size: nt = no + (b + i) – (d + e)initial population = 20,000,000