Are various forms of the same gene

Different forms of one gene are called alleles. Alleles of the same gene occupy the same locus of a specific chromosome.

an adaptation is a change or process by which an organism takes to be better suited for its environment. for example; migration is a behavioral adaptation, this is needed because birds are not built to last extremely cold climates. there are different adaptations because there are different species needing to adjust to different things, bears don't migrate; they hibernate.