Final answer:
The evolution of copy number in highly repetitive DNA sequences is influenced by gene duplication, mutation, selection, genetic drift, and transposition. Mobile genetic elements like transposons, including LINEs and elytron's, are pivotal in altering the structure and number of these sequences in the genome.
Step-by-step explanation:
The processes that appear to govern the evolution of copy number in highly repetitive DNA sequences include gene duplication, mutation, selection, genetic drift, and transposition. Gene duplication events allow for the extra copies of the genes to undergo modifications freely, through various processes such as mutation or selection, without the risk of losing the original gene function. This duplication can be a result of errors during DNA replication or due to the activity of mobile genetic elements like transposons. These transposable elements, also known as 'jumping genes', can add or remove large sections of DNA, which can lead to changes in the number of copies of certain sequences.
Transposons, in particular, have played a significant role in the evolution of genomes and the complexity of genomic DNA. They have contributed to both the diversity and evolution of sequences by cutting and pasting themselves into new locations or by replicating themselves within genomes. For instance, LINEs (Long Interspersed Nuclear Elements) and elytron's are two types of transposons that have influenced the structure of genomes. LINEs can cause exon shuffling, and elytron's are known to replicate through a rolling-circle mechanism, both contributing to genomic rearrangement and evolution.