The document provides a brief history of metagenomics, beginning in the 17th century when Antonie van Leeuwenhoek first observed microbes using microscopes. Key developments included the definition of microbial communities, techniques for culturing microorganisms, and the realization that culture-based techniques did not capture total microbial diversity. The field of metagenomics emerged in the late 20th century with developments like PCR, sequencing of 16S rRNA, and shotgun sequencing of environmental samples without culturing. This led to insights into uncultured microbes and their roles in environments like acid mine drainage. Global metagenomic sampling projects helped discover thousands of new microbial species.