Almost all rewrites start where your essay left off. Don't critique papers without suggesting how you would modify them. It is easy to be critical of most studies. The challenge is to figure out how to make them better. Be very clear about where you are in your essay.
Science is written in first person, active tense.
You already have a set of guidelines in the course prospectus on the format of the essay and how to cite papers in it. The comments below relate to things that have caused problems in previous years. I would like to head off some of these problems this year. Don't take on too big a topic. Stay away from complex things like the definition of adaptation or what is wrong with optimality theory for this essay.