The outline should include the overall structure of the essay (e.g., introduction, thesis, antithesis, synthesis, conclusion) AND a collection of the ideas that you plan to cover in the different parts.
What are the units of natural selection?
Genes, Organisms, Communities - One interesting angle might be to push this to the extremes: individual nucleotides, or the biosphere as a whole can hardly be considered as possible units of selection.
Can the genome be considered as an ecosystem?
Our genome consists to a large (or very large) part out of former selfish genetic elements that propagated and some still propagate in our genome. What, if any. is missed in this gene centered view of the genome?
Can ecological concepts be applied to relations between genes?
Symbiosis (= mutualism, parasitism, or commensalism) are usually applied to relations between organisms. However, molecular parasites, selfish genetic elements, and even protein domains can have (or "might have" or "always have") relationships to one another that might be described using the same terminology.
Trash to treasure - treasure to trash
Discuss one or more examples of selfish genetic elements and molecular parasites (more vermin than trash) making positive contributions to the host fitness on the long run (possible are inteins, introns, nonsense-mediated mRNA decay pathway, hedgehog proteins).
In your essay include a brief discussion whether or not this contribution initially qualifies as a nearly neutral pathway towards higher complexity.
Items to think about:
Suggested reading: