ABSTRACT
Terrestrial Habitats .............................................................................54 2.4 Summary ........................................................................................................ 55 Acknowledgment ..................................................................................................... 56 References ................................................................................................................ 56
Archaea and bacteria are dif cult to distinguish based on their morphology by microscopy because they were historically grouped together as prokaryotes. However, with the advent of molecular phylogenetic analysis of these taxa, we now know that archaea and bacteria are as different from each other as they are from Eukarya (Woese and Fox, 1977).
