Final answer:
The 'footprints' left by transposable elements in the genome are typically insertion sequences or distinctive sequence remnants resulting from their excision, which can serve as genetic markers for various genomic studies.
Step-by-step explanation:
The "footprints" that can be used to identify sites in the genome which used to be occupied by transposable elements are known as insertion sequences (IS Elements) or targeted sequence deletions resulting from the excision of these elements. Transposable elements, including transposons and retrotransposons, can move from one part of the genome to another ('jumping genes'), leaving behind a distinguishable sequence pattern upon their excision. The presence of variable number of tandem repeats (VNTRs) and single nucleotide polymorphisms (SNPs) are both indicative of such genetic mobility. When a transposable element moves, it can disrupt the function of a gene at the insertion site or leave behind a 'footprint' when it is excised. Geneticists can use these 'footprints' as genetic markers for studying genetic diversity, mapping the genome, and understanding evolutionary biology.