The shift from black grama grassland to desert shrubland that occurred on large portions of the Jornada Experimental Range in New Mexico illustrates how a rangeland can cross a threshold because of the interaction of several factors. How does this happen? Review the steps in the prompt. Organize the sequence of steps that illustrate how the rangeland evolved from black drama grass to scrubland of mesquite and creosote bushes.

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation:

correct answer: understand the different control methods available

integrated pest management is an strategy that is based on the ecosystem and try to prevent the pest and the damage caused by them by applying combination of technique like habitat manipulation, biological control and use of resistant varieties.

the main aim of the integrated pest management is not to completely eliminate the pest but to strengthen the ecosystem so that conditions are favorable for plants and unfavorable for pests.