ABSTRACT
Though invisible to the naked eye, our planet is teeming with microbes. The diversity of prokaryotic life can be attributed to several factors, including (1) their existence on this planet for at least 3.5 billions of year during which they evolved, (2) their short generation time (compared to multicellular life forms), and (3) their ability to shuffle around genetic material with ease via horizontal gene transfer. In stark contrast, metazoans and plants, while able to undergo genetic recombination through sexual reproduction, have only existed for 500-600 million years and have relatively longer generation times. Consequently, the genetic, and therefore metabolic, diversity of prokaryotes far surpasses that of multicellular eukaryotes.
