Nitrogen cycle could not live without if what

According to the theory of punctuated equilibrium, at what rate does speciation occur? species change depending on the rate of natural selection. after periods of stasis, new species evolve relatively rapidly. species change slowly and eventually form new species. some species change quickly and others change slowly to balance the overall rate.

Which of the following is not a main characteristic that scientists focus on when determining which kingdom an organism belongs to

Environmental differences within ecosystems are generally caused by